Showing papers on "Mitotic index published in 1999"

Prognosis of gastrointestinal smooth-muscle (stromal) tumors: dependence on anatomic site.

Abstract: Although the significance of various prognostic factors, such as tumor size and mitotic index (MI), has been well established for smooth-muscle tumors of the stomach, the significance of these factors in other sites is less well defined. We studied 1004 patients with gastrointestinal smooth-muscle tumors for whom vital status could be determined. The average MI and tumor size varied significantly among the five major sites examined: esophagus (53 cases), stomach (524 cases), small bowel 252 cases), colon/rectum (108 cases), and omentum/mesentery/peritoneum (67 cases). There was a significant difference in site-specific survival (p = 0.001), with 10-year survival varying between 50% and 70%. Multivariate analysis demonstrated tumor location (p = 0.0320), size (p = 0.0003), MI (p < 0.0001), and patient age (p < 0.0001) to each carry independent prognostic value. The significance of MI was highly site dependent. Separation of survival curves for the stomach, using a threshold for analysis of either 5 or 10 mitotic figures/50 high-power fields, was very good. In contrast, small-bowel tumors showed little separation between survival curves, regardless of whether a threshold of 1, 5, or 10 mitotic figures MF/50 high-power fields was used to distinguish groups. In no site were tumor size and MI alone sufficient to provide an accurate long-term prediction of prognosis. Although tumor location, size, MI, and age have independent value in predicting the prognosis of patients with gastrointestinal smooth-muscle tumors, better methods are still required to accurately predict clinical course.

The redox state of the ascorbate-dehydroascorbate pair as a specific sensor of cell division in tobacco BY-2 cells.

Abstract: The effects of ascorbate (ASC) and dehydroascorbate (DHA) on cell proliferation were examined in the tobacco Bright Yellow 2 (TBY-2) cell line to test the hypothesis that the ASC-DHA pair is a specific regulator of cell division. The hypothesis was tested by measuring the levels of ASC and DHA or another general redox pair, glutathione (GSH) and glutathione disulfide (GSSG), during the exponential-growth phase of TBY-2 cells. A peak in ASC, but not GSH, levels coincided with a peak in the mitotic index. Moreover, when the cells were enriched with ascorbate, a stimulation of cell division occurred whereas, when the cells were enriched with DHA, the mitotic index was reduced. In contrast, glutathione did not affect the mitotic-index peak during this exponential-growth phase. The data are consistent in showing that the ASC-DHA pair acts as a specific redox sensor which is part of the mechanism that regulates cell cycle progression in this cell line.

Comparison of Mitotic Index, In Vitro Bromodeoxyuridine Labeling, and MIB-1 Assays to Quantitate Proliferation in Breast Cancer

Abstract: PURPOSE: To investigate the hypothesis that in vitro bromodeoxyuridine (BrDu) labeling might be superior to MIB-1 immunostaining for prognostic value, because it more selectively labels cells during the S phase. METHODS: Four hundred eighty-six patients with breast cancers (59% lymph node-negative, 41% lymph node-positive) surgically excised between 1988 and 1993 (median follow-up, 62 months) were evaluated for cellular proliferation using prospective in vitro BrDu uptake assays, retrospective mitotic indices, and MIB-1 labeling. RESULTS: MIB-1, BrDu labeling, and mitotic index–derived proliferation data were highly correlated. Each was similarly associated with most other markers of prognosis, although these relationships were not identical. By univariate analysis, nodal status was the most significant prognostic variable for all patients. Higher BrDu labeling index, MIB-1 immunolabeling, and mitotic index were also associated with shortened disease-free survival (DFS) and disease-specific survival for t...

Insulin-like growth factor 1 is required for G2 progression in the estradiol-induced mitotic cycle

Abstract: Insulin-like growth factor 1 (IGF1) has been proposed as a “G1-progression factor” and as a mediator of estradiol’s (E2) mitogenic effects on the uterus. To test these hypotheses, we compared E2’s mitogenic effects on the uteri of Igf1-targeted gene deletion (null) and wild-type littermate mice. The proportion of uterine cells involved in the cell cycle and G1- and S-phase kinetics were not significantly different in wild-type and Igf1-null mice. However, the appearance of E2-induced mitotic figures and cell number increases were profoundly retarded in Igf1-null uterine tissue. There was a significant increase in nuclear DNA concentration in Igf1-null cells, consistent with a G2 arrest. Interestingly, apoptotic cells were also significantly reduced in abundance, and the normal massive apoptotic response to E2 withdrawal was absent in the Igf1-null uterus. These data show that Igf1 is an essential mediator of E2’s mitogenic effects, with a critical role not in G1 progression but in G2 progression.

Effect of retinoids on AOM-induced colon cancer in rats: modulation of cell proliferation, apoptosis and aberrant crypt foci

Abstract: We have previously reported that the retinoids, 4-(hydroxy-phenyl)retinamide (4-HPR) and 9-cis-retinoic acid (RA) prevented azoxymethane (AOM)-induced colon tumors and along with 2-(carboxyphenyl)retinamide (2-CPR) prevented aberrant crypt foci (ACF). In this study, we evaluated the effect of 2-CPR on AOM-induced colon tumors and the effect of the three retinoids on apoptosis and cell proliferation. Male F344 rats were administrated 15 mg/kg AOM at weeks 7 and 8 of age. 2-CPR (315 mg/ kg) was administered in the diet starting either 1 week before or at week 12 after the first dose of AOM. The rats continued to receive the 2-CPR until killed at week 46. Unlike the demonstrated prevention of colon cancer by the other two retinoids, both dosing schedules of 2-CPR resulted in an approximate doubling of the yield of colon tumors. In adenomas, 2-CPR, 4-HPR and 9-cis-RA were equally effective in reducing mitotic activity, while only 4-HPR and 9-cis-RA but not 2-CPR enhanced apoptosis. When administered for only the 6 days prior to killing 4-HPR but not 2-CPR decreased the Mitotic Index and increased the Apoptotic Index in adenomas. In non-involved crypts, chronic exposure to 4-HPR and 9-cis-RA in contrast to 2-CPR reduced the Mitotic Index and enhanced the Apoptotic Index. In concurrence with our previous study, both 2-CPR and 4-HPR were very potent in preventing ACF when administered in the diet starting 1 week before the first dose of AOM and continuing for the 5 weeks of the study. Hence, unlike the other two retinoids, 2-CPR, although very potent in preventing ACF, enhanced rather than prevented AOM-induced colon cancer. Furthermore, our results suggest that the effect of 2-CPR on tumor yield is different from 4-HPR and 9-cis-RA because, unlike them, it does not enhance apoptosis.

Dietary glycine inhibits the growth of B16 melanoma tumors in mice.

Abstract: Dietary glycine inhibited hepatocyte proliferation in response to the carcinogen WY-14,643. Since increased cell replication is associated with hepatic cancer caused by WY-14,643, glycine may have anti-cancer properties. Therefore, these experiments were designed to test the hypothesis that dietary glycine would inhibit the growth of tumors arising from B16 melanoma cells implanted subcutaneously in mice. C57BL/6 mice were fed diet supplemented with 5% glycine and 15% casein or control diet (20% casein) for 3 days prior to subcutaneous implantation of B16 tumor cells. Tumor volume was estimated from tumor diameter for 14 days. Tumors were excised, weighed and sectioned for histology post-mortem. B16 cells and endothelial cells were cultured in vitro to assess effects of glycine on cell growth. Statistical tests were two-sided and a P-value of 0.05 was defined as a significant difference between groups. Weight gain did not differ between mice fed control and glycine-containing diets. B16 tumors grew rapidly in mice fed control diet; however, in mice fed glycine diet, tumor size was 50-75% less. At the time of death, tumors from glycine-fed mice weighed nearly 65% less than tumors from mice fed control diet (P < 0.05). Glycine (0.01-10 mM) did not effect growth rates of B16 cells in vitro. Moreover, tumor volume and mitotic index of B16 tumors in vivo did not differ 2 days after implantation when tumors were small enough to be independent of vascularization. After 14 days, tumors from mice fed dietary glycine had 70% fewer arteries (P < 0.05). Furthermore, glycine (0.01-10 mM) inhibited the growth of endothelial cells in vitro in a dose-dependent manner (P < 0.05; IC50 = 0.05 mM). These data support the hypothesis that dietary glycine prevents tumor growth in vivo by inhibiting angiogenesis through mechanisms involving inhibition of endothelial cell proliferation.

Phenylahistin arrests cells in mitosis by inhibiting tubulin polymerization

Abstract: (-)-Phenylahistin, a fungal diketopiperazine metabolite composed of phenylalanine and isoprenylated dehydrohistidine, arrested cells in mitosis and inhibited the proliferation of A549 cells. The microtubule network in A549 cells was disrupted by (-)-phenylahistin, which also inhibited the polymerization of both microtubule protein from bovine brain and phosphocellulose-purified tubulin in vitro. Competitive binding studies indicated that (-)-phenylahistin interacted with the colchicine binding site on tubulin but not with the vinblastine binding site.

The utility of mitotic index, oestrogen receptor and Ki-67 measurements in the creation of novel prognostic indices for node-negative breast cancer.

Abstract: Introduction:Prognostic factors can be useful to identify node-negative patients at increased risk of relapse who should receive adjuvant treatment. In the past, oestrogen receptor status and mitotic index have been shown to be significant predictors of prognosis. Different techniques for the measurement of these prognostic factors are available.Methods:Paraffin-embedded tumour specimens from 441 pre-menopausal patients with node-negative breast cancer who were previously randomized onto a trial comparing peri-operative chemotherapy with no further therapy were studied. Oestrogen receptor status was determined by the classical biochemical assay and by immunohistochemistry (ER-IA). Mitotic index was assessed by counting the number of mitoses and by calculating the percentage of tumour cells positively staining for the antibody Ki-67.Results:There was a good correlation between ER-IA and the biochemical ER-assay (P<0.01), and the percentage of Ki-67 positive tumour cells and mitotic counts (P<0.01) respectively. However, ER-IA significantly predicted disease-free survival (RR=2.67, 95% CI: 1.60–4.44,P<0.01) whereas the biochemical assay was only borderline significant (RR=1.54, 95% CI: 1.00–2.36,P=0.05). Similarly, Ki-67 was a stronger indicator of prognosis (RR=2.84, 95% CI: 1.80–4.48,P<0.01) than mitotic counts (RR=1.56, 95% CI: 1.22–2.00,P<0.01).Conclusions:We conclude that ER-IA performs better in predicting prognosis than the classical biochemical oestrogen receptor assay. Ki-67 is a more accurate marker for tumour cell proliferation and predicts prognosis of patients with breast cancer better than do mitotic counts.

Apoptotic and mitotic indices predict survival rates in lymph node-negative colon carcinomas.

Abstract: An imbalance between apoptosis and mitosis is believed to underlie colon cancer development and progression. These processes regulate the growth of normal and neoplastic epithelia, and in tumors, may confer prognostic information. To test this hypothesis, we determined apoptotic and mitotic indices (AI, MI) by morphology in HE MI correlated with PI (P = 0.02) and inversely with Bcl-2 in distal tumors (P = 0.02). p53 and Bcl-2 expression were detected in 52 and 53% of tumors, respectively. Distal tumor site was associated with aneuploidy (P = 0.001), p53 (P = 0.001), and PI > 15% (P = 0.002). In a univariate analysis, colon cancers with high MIs (>0.5%) had a poor prognosis (P = 0.04). Bcl-2 overexpression (>20% + tumor cells) was associated with more favorable OS (P = 0.04). The association of ploidy and PI with outcome was of borderline significance for all tumors; however, diploidy predicted better survival in proximal cancers. In distal cancers, low AIs ( 0.5%) were adverse prognostic markers. After adjustment for other variables, an increased MI predicted shorter OS with a hazard ratio (HR) for death of 2.70; 95% confidence interval (CI) was 1.23-5.91 (P = 0.01). Expression of Bcl-2 was associated with more favorable OS (HR, 0.46; 95% CI, 0.21-1.0; P = 0.06). In proximal cancers, Bcl-2 expression was the most important predictor of OS (HR, 0.17; 95% CI, 0.03-0.85; P = 0.03). In distal tumors, low AIs (HR, 3.33; 95% CI, 1.27-9.09; P = 0.01) and high MIs predicted poor survival. In conclusion, increased mitosis and low or absent Bcl-2 expression are significant risk factors for death in node-negative colon cancers, as are low rates of apoptosis in distal tumors. If validated prospectively, our results may identify patient subsets than can benefit from adjuvant chemotherapy.

Apoptosis in breast cancer: relationship with other pathological parameters.

Abstract: Apoptosis is a frequent phenomenon in breast cancer and it can be detected by light microscopy in conventional histopathological sections or by special staining techniques. The number of apoptotic cells as a percentage of cells present, or the number of apoptotic cells per square millimetre of neoplastic tissue, is usually described as the apoptotic index (AI). In breast cancer, the AI is not related to tumour size, axillary lymph node metastasis or distant metastasis at diagnosis. It is greater in invasive ductal carcinomas than in other histological types. High AI is also related to high histological grade, high nuclear grade, comedo-type necrosis, lack of tubule formation, and dense infiltration of the tumour by lymphocytes. Sex steroid receptor-negative tumours have greater AIs than the sex steroid receptor-positive ones. Aneuploid breast cancers with high S-phase fractions (SPFs) also have high AI values compared with diploid tumours with low SPFs. p53-Positive breast cancers have high AIs, whereas tumours that are Bcl-2 positive have low AIs. The AI shows a strong positive correlation to all direct or indirect indicators of cell proliferation, such as mitotic index and Ki67 immunolabelling. Univariate survival analyses show that a high AI is linked with unfavourable disease outcome in axillary lymph node-negative and -positive breast cancer, but multivariate analyses indicate that AI is not an independent prognostic factor. In conclusion, a high AI is related to malignant cellular features and indicators of invasiveness and cell proliferation in breast cancer.

Overexpression of BRCA2 gene in sporadic breast tumours.

Abstract: The breast cancer susceptibility gene BRCA2 is expressed in a wide range of tissues as an 11-kb mRNA transcript that encodes a 3418-amino acid protein involved in the response to DNA damage. To obtain better a molecular characterization of BRCA2 expression in sporadic breast cancer, we quantified BRCA2 mRNA by means of RT – PCR in a large series of human primary breast tumours. BRCA2 expression showed wide variations in tumour tissues, being underexpressed in 14/127 (11%) and overexpressed in 25/127 (20%). BRCA2 overexpression (but not underexpression) correlated significantly with Scarff, Bloom and Richardson (SBR) histopathological grade III (P=0.007) and was mainly attributed to nuclear polymorphism (P=0.005) and mitotic index (P=0.048), suggesting that the BRCA2 gene contributes to the proliferation rate in breast tumours. BRCA2 status (under and/or overexpression versus normal expression) was not associated with subsequent relapse and with significantly shorter disease-free survival. The observed disruption of BRCA2 expression is not due to allelic loss, because the latter did not correlate with altered BRCA2 mRNA expression in our tumour series. Taken together, these data suggest the involvement, especially by overexpression, of the BRCA2 gene in sporadic breast tumours, and the existence of another important tumour-suppressor gene in breast cancer, in the 13q12-q13 region.

Expression of cyclin A and D proteins in prostate cancer and their relation to clinopathological variables and patient survival.

Abstract: BACKGROUND. Cell proliferation and its regulation are important determinants of the prognosis of prostate cancer patients. Cyclins are important regulators of cell proliferation in human cancer, but their prognostic value has not been previously analyzed in prostate cancer. METHODS. The immunohistochemical expression and prognostic value of cyclins A and D were studied in prostate cancer in a cohort of 213 patients followed-up for a mean of 12 years. RESULTS. The expression of cyclin A was both cytoplasmic and nuclear, whereas the expression of cyclin D was nuclear. The mean (SD) fraction of cyclin A- and cyclin D-positive cells was 2.1 (7.9)% and 16.3 (23.4)%, respectively. The expression of cyclin A was related to TM-category, histological differentiation, perineural invasion, S-phase fraction, and expression of Ki67 and bcl-2 (for all, P < 0.05). The expression of cyclin D was related to TM-classification, histological differentiation, perineural invasion, DNA ploidy, S-phase fraction, expression of Ki67, and mitotic index (for all, P ≤ 0.01). In survival analysis, expression of cyclin A predicted cancer-related survival in the entire cohort (P < 0.001). Expression of cyclin D predicted cancer-related survival in the entire cohort (P < 0.0001), in M0 (P = 0.0007), and in T1-2NxM0 tumors (P = 0.0003). In Cox multivariate analysis, T-category, M-category, patient age, and the fraction of cyclin A-positive cells were independent predictors of survival in the entire series. In local tumors, T-category, Gleason score, DNA ploidy, or S-phase fraction were independent prognostic factors, and cyclins had no independent prognostic value. CONCLUSIONS. The results show that the expression of cyclins A and D is related to several malignant cellular features in prostate cancer, but they have no independent prognostic value. Prostate 38:175-182, 1999.

Balance of cell proliferation and apoptosis in breast carcinogenesis.

Abstract: We determined the mitotic and apoptotic index through the spectrum of pre‐invasive ductal breast lesions to invasive carcinoma in search of disturbances in the proliferation/cell death balance in breast carcinogenesis Seventy‐two pure pre‐invasive ductal breast lesions (without invasive carcinoma) and 103 invasive breast carcinomas were used The numbers of mitotic and apoptotic cells were microscopically counted in hematoxylin and eosin stained sections (MI and Al, respectively), and the ratio of the values of MI and AI was calculated for each individual case (M/A index) A distinction was made between well differentiated and poorly differentiated breast lesions, based on histological type and nuclear grade, to arrive at two plausible progression models for breast carcinogenesis For the well differentiated breast lesions, the MI was rather equal for hyperplasias and well differentiated DCIS, but increased 6‐fold from DCIS to well differentiated invasive carcinoma The AI remained in the same range, resulting in a 4‐fold increase of the M/A index For the poorly differentiated breast lesions, a significant increase in MI and AI was found from hyperplasia to poorly differentiated DCIS From DCIS to poorly differentiated invasive carcinoma, the MI increased significantly and the AI decreased 2‐fold (ns), resulting in a 25‐fold significant increase of the M/A index In conclusion, the net increase of the number of cells in the transition from well differentiated pre‐invasive to well differentiated invasive carcinoma is accompanied by an increase of cell proliferation rather than decrease in apoptosis, suggesting that in these lesions, proliferation related mechanisms are most important in carcinogenesis and progression In contrast, in poorly differentiated breast lesions, decreased apoptosis seems to be also important in carcinogenesis and progression At present, we are gathering patients with invasive breast cancer who had a previous biopsy with a pre‐invasive lesion to obtain further more direct evidence for this hypothesis

Induction of polyploidy and apoptosis after exposure to high concentrations of the spindle poison nocodazole

Abstract: The proportions of aneuploid/polyploid versus euploid cells formed after treatment with spindle poisons like nocodazole are of course dependent on the relative survival of cells with numerical chromosome aberrations. This work aimed at studying the survival of polyploid cells formed after treatment with a nocodazole concentration sufficient to significantly decrease tubulin polymerization (0.1 microg/ml). First, normal primary lymphocytes were analysed and the following complementary chromosomal parameters were quantified: mitotic index, frequency of abnormal mitoses, polyploid metaphases and apoptotic cells. The results clearly indicate a positive correlation between abnormal mitotic figures, apoptosis and the induction of polyploidy. They therefore led to a single cell approach in which both apoptosis and polyploidy induction could be scored in the same cell. For this purpose, actively proliferating cells are required and two human leukaemic cell lines were used, KS (p53-positive) and K562 (p53-negative), which have a near-triploid karyotype. Cells were separated into an apoptotic and a viable fraction by means of annexin-V staining and flow cytometry. In KS, treatment with nocodazole induced a similar fraction of hexaploid cells in both the viable and apoptotic fraction, but no dodecaploid cells were ever observed. In contrast, a population of dodecaploid cells (essentially viable) was clearly observed in the K562 cell line. The results in KS, as compared with K562, confirm that wild-type p53 can prevent further cycling of polyploid cells by blocking rereplication. The most probable explanation for these data is that not only the mitotic spindle but also interphase microtubules are sensitive to nocodazole treatment. Our data thus strongly suggest that besides the G(1)/S checkpoint under the control of p53, the G(2)/M transition may be sensitive to depolymerization of microtubules, possibly under the control of Cdc2, Bcl-2, Raf-1 and/or Rho.

BUBR1 Phosphorylation Is Regulated during Mitotic Checkpoint Activation

Abstract: Eukaryotic cells have evolved a mechanism that delays the progression of mitosis until condensed chromosomes are properly positioned on the mitotic spindle. To understand the molecular basis of such monitoring mechanism in human cells, we have been studying genes that regulate the mitotic checkpoint. Our early studies have led to the cloning of a fulllength cDNA encoding MAD3-like protein (also termed BUBR1/MAD3/SSK1). Dot blot analyses show that BUBR1 mRNA is expressed in tissues with a high mitotic index but not in differentiated tissues. Western blot analyses show that in asynchronous cells, BUBR1 protein primarily exhibits a molecular mass of 120 kDa, and its expression is detected in most cell lines examined. In addition, BUBR1 is present during various stages of the cell cycle. As cells enter later S and G 2, BUBR1 levels are increased significantly. Nocodazolearrested mitotic cells obtained by mechanical shakeoff contain BUBR1 antigen with a slower mobility on denaturing SDS gels. Phosphatase treatment restores the slowly migrating band to the interphase state, indicating that the slow mobility of the BUBR1 antigen is attributable to phosphorylation. Furthermore, purified recombinant His6-BUBR1 is capable of autophosphorylation. Our studies indicate that BUBR1 phosphorylation status is regulated during spindle disruption. Considering its strong homology to BUB1 protein kinase, BUBR1 may also play an important role in mitotic checkpoint control by phosphorylation of a critical cellular component(s) of the mitotic checkpoint pathway.

Establishment of a highly metastatic human ovarian cancer cell line (HO-8910PM) and its characterization.

Abstract: To establish a highly metastatic human ovarian cancer cell line and to study its characteristics tissue from the tumor mass of a nude mouse of 7th subtransplantation of the highly metastasizing human ovarian cancer model (NSMO) was cultured in vitro and the cell line HO-8910PM was established. The cell line grew well through 87 passages and the mitotic index, chromosome analysis, morphology under electron microscope and some oncoprotein expression were studied. The cell doubling time was 34.5 h and the mitotic index was 44.3%. The cells were all of epithelial type and most of them were of polygonal shape. Electron microscopic examination showed malignant nuclei with enlarged nucleoli and abundant microvilli. The plating efficiency in soft agar was 31.2%. The cell agglutination appeared in 4 ug/ml PHA. Chromosomal analysis revealed a mode of 54 per cell. The DNA index was 1.57 measured by FCM. Both of them showed hyperdiploid. Positive ER and PR granules were found in the cells. After hetero-transplantation of the cells into three nude mice all of the latter showed tumor growth with metastasis in lungs or lymph nodes. Eight of the nine kinds of oncoprotein detected by immnohistochemical method were found in the cells. The detection for mycoplasma showed negative. After storage in liquid nitrogen cell growth was stable. The cell line HO-8910PM can meet the criteria for the establishment cell lines. This cell line and NSMO model would be very useful in study of the mechanism of cancer metastasis in identifying various cellular factors regulating local and distant metastasis and also in establishing a rational approach for searching after anti-metastatic agents.

A matched observational study of canine survival with primary intraocular melanocytic neoplasia

Abstract: A retrospective histopathologic study was performed to evaluate the effect of primary intraocular melanocytic neoplasia on canine survival. Tumor size, location within the globe, extent of infiltration, and mitotic index were analyzed for their potential to predict survival. A total of 244 cases of dogs with melanocytic tumors submitted to the Comparative Ocular Pathology Laboratory of Wisconsin from 1988 to 1998 were evaluated. Histopathologic criteria (mitotic index, cytologic features of anaplasia) were used to differentiate 188 benign melanocytomas from 56 malignant melanomas. Signalment evaluation of age, sex, and breed revealed similarities in both tumor populations, with the majority of tumors discovered in 9-year-old, female/spayed, mixed-breed dogs. A greater percentage of left eyes (66%) vs. right eyes (47%) was found in the melanoma population, but an equal distribution was found in the melanocytoma population (48% and 52%, respectively). The majority of tumors arose from the anterior uveal tract (79% in the melanocytoma and 95% in the malignant melanoma populations). The German Shepherd breed was predisposed in the limbal distribution. At the time of enucleation, most tumors had invaded the sclera, but did not show extrascleral extension (51% in the melanocytoma and 61% in the malignant melanoma populations). Survival analysis showed a significant difference in survival between control and malignant melanoma populations (P = 0.0081) and was suggestive of a difference between the melanocytoma and melanoma populations (P = 0.031). Tumor extension, tumor size, and mitotic index were not found to be reliable predictors of survival.

Apoptosis and proliferation in relation to histopathological variables and prognosis in hepatocellular carcinoma.

Abstract: The prognosis of patients with resectable hepatocellular carcinoma depends mainly on the anatomical extent of the tumour and on the general condition of the patient. Given the growing evidence that proliferation indices may be of prognostic significance in hepatocellular carcinomas and that parameters of cell loss (usually, but not exclusively, due to programmed cell death) are biologically relevant, the identification and quantitation of proliferative capacity and apoptosis may be of prognostic importance. In this study four different methods have been used to assess proliferation in a series of 193 curatively (R0) resected hepatocellular carcinomas: mitotic count, immunohistochemical assessment of MIB-1 (Ki-67), proliferating cell nuclear antigen (PCNA), and silver-stained nucleolar organizer regions (AgNORs). Apoptosis was assessed using the in situ-end labelling (ISEL) technique in combination with morphological criteria. Patients who received liver transplantation were excluded. The results obtained were compared with histopathological stage (according to UICC), Edmondson grade, several other histopathological factors, and survival rate. Significant statistical correlations were seen between the mitotic index, the rate of nuclear positivity for MIB-1 and PCNA, and the number of AgNOR dots. In univariate survival analysis, tumour stage and Edmondson grade, mitotic index, MIB-1 and PCNA index, and mean AgNOR number were significant factors influencing patients' survival. On multivariate Cox survival analysis, mitotix index, concomitant cirrhosis, Edmondson grade, and patient age were the only significant independent prognostic factors. Apoptosis was not related to prognosis or to other parameters examined. These results indicated that mitotic index is an additional prognostic parameter which could provide auxiliary information for patients' outcome. MIB-1 and PCNA immunostaining and AgNORs showed a good correlation among themselves. Apoptosis did not predict prognosis in hepatocellular carcinoma.

Breast tumors with myofibroblastic differentiation: clinico-pathological observations in myofibroblastoma and myofibrosarcoma.

Abstract: This report describes the clinico-pathological features of myofibroblastic tumors of the breast in six patients. Four women and one man presented with a benign myofibroblastoma. The sixth patient was a woman with myofibrosarcoma. All myofibroblastomas were composed of a fascicular arrangement of spindle cells embedded in dense bundles of collagen. Tumors differed with respect to their proportion of neoplastic cells and collagenous stroma as well as cellular pleomorphism. Based on this variation, the tumors could be subclassified as classic, collagenized, epithelioid and cellular myofibroblastoma. Immunohistological staining confirmed myofibroblastic differentiation by strong expression of either desmin or smooth muscle actin with coexpression of vimentin. In addition, numerous cells reacted with antibodies to CD68. Proliferative activity was rather low in the myofibroblastoma with an average of 0-2 mitotic figures per 10 HPF. DNA cytometric analysis was performed in two cases and showed diploid stem lines with minor S-phase fractions (1% and 3%). In the myofibrosarcoma, cells contained pleomorphic nuclei with some giant cells and numerous mitotic figures (6-7/10 HPF) and had infiltrating margins that were apparent even grossly. Immunohistochemically, tumor cells strongly expressed vimentin, smooth muscle actin and fibronectin. Ultrastructurally, neoplastic cells met the criteria of myofibroblasts, i.e. contained abundant intermediate filaments and myofilament bundles with focal densities as well as fibronexus junctions. DNA cytometric analysis exhibited again a diploid stemline but marked proliferative activity was present as indicated by an S-phase fraction of 20%. In conclusion, in benign myofibroblastoma there may be some cellular pleomorphism but mitotic activity is always low. The malignant counterpart, myofibrosarcoma, is characterized by marked cellular pleomorphism, infiltrating margins and high mitotic rate.

Association of Bcl-2 protein expression with gallbladder carcinoma differentiation and progression and its relation to apoptosis.

Abstract: BACKGROUND Bcl-2 protein is believed to play a role in neoplasia by inhibiting tumor cell apoptosis. To assess its contribution to gallbladder tumorigenesis and cancer progression, an immunohistochemical study was performed. METHODS Fifteen adenomas and 68 adenocarcinomas were immunohistochemically and histopathologically investigated for the relation of Bcl-2 expression to p53 status, apoptosis (apoptotic index, AI), and proliferation activity (mitotic index, MI; Ki-67 labeling index, Ki-67 LI). RESULTS The Bcl-2 score, based on intensity and extent, decreased in the order of adenoma, well-differentiated, and moderately to poorly differentiated adenocarcinoma. Early stage carcinomas demonstrated significantly higher Bcl-2 scores than their advanced counterparts (P < 0.05). On the other hand, p53 score, MI, Ki-67 LI, and AI increased in the same order. The Bcl-2 negative adenocarcinomas displayed higher AI and AI-to-MI ratios than the Bcl-2 positive group, especially in the early stage, well-differentiated lesions. A significantly positive correlation between MI(r = 0.549) or Ki-67 LI(r = 0.446) and AI was observed. In early stage carcinomas, adenomatous components in the lesions were found more frequently in the polypoid lesions than in the nonpolypoid lesions (P < 0.05). CONCLUSIONS Expression of Bcl-2 protein in gallbladder tumors appears to be positively associated with tumor cell differentiation and inversely with tumor progression. It may thus play a role in regulating carcinoma growth, especially in the early stage of tumorigenesis. It is believed that the polypoid carcinomas may arise from preexisting adenomas but the nonpolypoid carcinomas may arise as de novo carcinoma. Cancer 1999;85:318–25. © 1999 American Cancer Society.

Retinoblastoma-related p107 and pRb2/p130 proteins in malignant lymphomas: distinct mechanisms of cell growth control.

Abstract: pRb/p105, p107, and pRb2/p130 compose the retinoblastoma (RB) family of proteins and regulate cellular growth and differentiation. Because recent functional studies have indicated that the expression of the RB-related proteins p107 and pRb2/p130 are tightly cell cycle regulated, we were interested in investigating their expression along with cellular kinetic characteristics and proliferative features of non-Hodgkin's lymphomas (NHLs). p107 and pRb2/ p130 expression was determined immunohistochemically in biopsy specimens from 83 untreated patients with NHLs of various histiotypes. The expression of these two RB-related proteins was correlated with the mitotic index, apoptotic index, and percentages of Ki-67(+), cyclin A(+), p34(+), and cyclin B(+) cells. The overall survival rate was evaluated according to the Kaplan-Meier method and the log-rank test. We found a positive correlation between the percentages of cells positive for p107 and proliferative features such as mitotic index and percentage of Ki-67(+) and cyclin A(+) cells, whereas such correlation could not be demonstrated for the percentages of pRb2/p130 positive cells. Low immunohistochemical levels of pRb2/p130 detected in untreated patients with NHLs of various histiotypes inversely correlated with a large fraction of cells expressing high levels of p107 and proliferation-associated proteins. Such a pattern of protein expression is normally observed in continuously cycling cells. Interestingly, such cases showed the highest survival percentage (82.5%) after the observation period of 10 years. Thus, down-regulation of the RB-related pRb2/p130 protein could be one of the reasons why these cases display such a high rate of proliferation and why they respond so well to therapy.