/pdf/inhibitors-of-mammalian-g1-cyclin-dependent-kinases-38eef2u6ay.pdf

Inhibitors of mammalian G1 cyclin-dependent kinases.

The development and progression of cancer and the experimental reversal of tumorigenicity are accompanied by complex changes in patterns of gene expression. Microarrays of cDNA provide a powerful tool for studying these complex phenomena. The tumorigenic properties of a human melanoma cell line, UACC-903, can be suppressed by introduction of a normal human chromosome 6, resulting in a reduction of growth rate, restoration of contact inhibition, and suppression of both soft agar clonogenicity and tumorigenicity in nude mice. We used a high density microarray of 1,161 DNA elements to search for differences in gene expression associated with tumour suppression in this system. Fluorescent probes for hybridization were derived from two sources of cellular mRNA [UACC-903 and UACC-903(+6)] which were labelled with different fluors to provide a direct and internally controlled comparison of the mRNA levels corresponding to each arrayed gene. The fluorescence signals representing hybridization to each arrayed gene were analysed to determine the relative abundance in the two samples of mRNAs corresponding to each gene. Previously unrecognized alterations in the expression of specific genes provide leads for further investigation of the genetic basis of the tumorigenic phenotype of these cells.

Use of a cDNA microarray to analyse gene expression patterns in human cancer.

https://www.cell.com/cell/pdf/0092-8674(95)90039-X.pdf

Mice Lacking p21CIP1/WAF1 undergo normal development, but are defective in G1 checkpoint control

Mice Lacking p27Kip1 Display Increased Body Size, Multiple Organ Hyperplasia, Retinal Dysplasia, and Pituitary Tumors

Review of the biological properties and toxicity of bee propolis (propolis)

The melanoma differentiation associated gene, mda-6, which is identical to the P53-inducible gene WAF1/CIP1, encodes an M(r) 21,000 protein (p21) that can directly inhibit cell growth by repressing cyclin dependent kinases. mda-6 was identified using subtraction hybridization by virtue of its enhanced expression in human melanoma cells induced to terminally differentiate by treatment with human fibroblast interferon and the anti-leukemic compound mezerein (Jiang and Fisher, 1993). In the present study, we demonstrate that mda-6 (WAF1/CIP1) is an immediate early response gene induced during differentiation of the promyelocytic HL-60 leukemia cell line along the granulocytic or macrophage/monocyte pathway. mda-6 gene expression in HL-60 cells is induced within 1 to 3 h during differentiation along the macrophage/monocyte pathway evoked by 12-0-tetradecanoyl phorbol-13-acetate (TPA) or 1,25-dihydroxyvitamin D3 (Vit D3) or the granulocytic pathway produced by retinoic acid (RA) or dimethylsulfoxide (DMSO). Immunoprecipitation analyses using an anti-p21 antibody indicate a temporal induction of p21 protein following treatment with TPA, DMSO or RA. A relationship between rapid induction of mda-6 gene expression and differentiation is indicated by a delay in this expression in an HL-60 cell variant resistant to TPA-induced growth arrest and differentiation. A similar delay in mda-6 gene expression is not observed in Vit D3 treated TPA-resistant variant cells that are also sensitive to induction of monocytic differentiation. Since HL-60 cells have a null-p53 phenotype, these results demonstrate that p21 induction occurs during initiation of terminal differentiation in a p53-independent manner. In this context, p21 may play a more global role in growth control and differentiation than originally envisioned.

Induction of differentiation in human promyelocytic HL-60 leukemia cells activates p21, WAF1/CIP1, expression in the absence of p53.

The combination of recombinant human fibroblast interferon (IFN-beta) and the antileukemic compound mezerein (MEZ) induces terminal differentiation with an irreversible loss of proliferative capacity in human melanoma cells. Using subtraction hybridization, cDNAs were identified that display enhanced expression in terminally differentiated and growth arrested human melanoma cells (Jiang and Fisher, 1993; Jiang et al., 1994a). A specific melanoma differentiation-associated (mda) cDNA, mda-6, is described whose expression inversely correlates with melanoma progression and growth. mda-6 is identical to WAF1/CIP1/SDI1 that encodes the M(r) 21,000 protein (p21) that is an inhibitor of cyclin-dependent kinases. Actively growing normal melanocyte, SV40-immortalized human melanocyte and dysplastic nevus cell lines synthesize elevated levels of mda-6 mRNA; whereas, actively proliferating radial and early vertical growth phase primary melanomas as well as metastatic human melanoma cells produce reduced levels of mda-6 mRNA. Treatment of primary and metastatic human melanoma cells with IFN-beta + MEZ results in growth inhibition and an increase in mda-6 expression. mda-6 expression also increases when human melanoma cells are grown to high saturation densities or when grown in serum-free medium. Using anti-p53 and anti-p21 antibodies, an inverse correlation is found between p53 and p21 protein levels during growth arrest and differentiation. Induction of growth arrest and terminal differentiation in H0-1 human melanoma cells by IFN-beta + MEZ results in a temporal decrease in wild-type p53 protein levels with a corresponding increase in p21 levels. In the Matrigel-assisted melanoma progression model, mda-6 expression decreases in early vertical growth phase primary human melanoma cells selected for autonomous or enhanced tumor formation in nude mice. In metastatic human melanoma cells displaying a loss of metastatic potential resulting from introduction of a normal human chromosome 6, mda-6 mRNA levels increase. Taken together, these studies indicate that mda-6 (p21) may function as a negative regulator of melanoma growth, progression and metastasis.

The melanoma differentiation-associated gene mda-6, which encodes the cyclin-dependent kinase inhibitor p21, is differentially expressed during growth, differentiation and progression in human melanoma cells.

The selective production of monoclonal antibodies (mAbs) reacting with defined cell surface-expressed molecules is now readily accomplished with an immunological subtraction approach, surface-epitope masking (SEM). Using SEM, prostate carcinoma (Pro 1.5) mAbs have been developed that react with tumor-associated antigens expressed on human prostate cancer cell lines and patient-derived carcinomas. Screening a human LNCaP prostate cancer cDNA expression library with the Pro 1.5 mAb identifies a gene, prostate carcinoma tumor antigen-1 (PCTA-1). PCTA-1 encodes a secreted protein of approximately 35 kDa that shares approximately 40% sequence homology with the N-amino terminal region of members of the S-type galactose-binding lectin (galectin) gene family. Specific galectins are found on the surface of human and marine neoplastic cells and have been implicated in tumorigenesis and metastasis. Primer pairs within the 3' untranslated region of PCTA-1 and reverse transcription-PCR demonstrate selective expression of PCTA-1 by prostate carcinomas versus normal prostate and benign prostatic hypertrophy. These findings document the use of the SEM procedure for generating mAbs reacting with tumor-associated antigens expressed on human prostate cancers. The SEM-derived mAbs have been used for expression cloning the gene encoding this human tumor antigen. The approaches described in this paper, SEM combined with expression cloning, should prove of wide utility for developing immunological reagents specific for and identifying genes relevant to human cancer.

https://www.pnas.org/content/pnas/93/14/7252.full.pdf

Surface-epitope masking and expression cloning identifies the human prostate carcinoma tumor antigen gene PCTA-1 a member of the galectin gene family

The active component of the honeybee hive product propolis, caffeic acid phenthyl ester (CAPE), induces a selective growth suppressive and toxic effect toward cloned rat embryo fibroblast cells transformed by adenovirus type 5 (Ad5) or the Ad5 E1A transforming gene versus untransformed cloned rat embryo fibroblast cells (Z-z. Su et al. , Mol. Carcinog., 4: 231–242, 1991). The present study was conducted to determine whether CAPE-induced growth suppression/toxicity was a direct result of expression of the Ad5 E1A and E1B transforming genes or a consequence of the action of these genes resulting in the transformed state. For this investigation we used somatic cell hybrids and 5-azacytidine-treated Ad5-transformed rat embryo cells that display different stages of expression of the transformed phenotype. This series of cell lines has permitted us to determine whether expression of the transformed state and the stage of transformation progression regulates CAPE sensitivity. Evidence is presented indicating that sensitivity to CAPE is directly determined by the state of expression of the transformed progression phenotype, as opposed to simply the expression of the Ad5 E1A and E1B transforming genes. These results provide further evidence that CAPE may represent a unique compound that can specifically target progressed transformed cells for growth suppression and toxicity. An understanding of the mechanism underlying this selective effect of CAPE could result in the identification of important biochemical pathways mediating cellular transformation and progression of the transformed state.

https://cancerres.aacrjournals.org/content/canres/54/7/1865.full.pdf

Growth Suppression and Toxicity Induced by Caffeic Acid Phenethyl Ester (CAPE) in Type 5 Adenovirus-transformed Rat Embryo Cells Correlate Directly with Transformation Progression

Rapid expression cloning and differential RNA display identifies a gene, named prostate tumor inducing gene-1 ( PTI-1 ), that is differentially expressed in prostate cancer versus normal prostate and benign prostatic hypertrophy. PTI-1 encodes a truncated and mutated human elongation factor 1α, and its 5′ untranslated region (UTR) shares significant homology with the 23S rRNA gene of Mycoplasma hyopneumoniae . PCR with human genomic DNAs, using PTI-1 5′ UTR-specific primers, suggests that this sequence is part of the human genome. Furthermore, reverse transcription (RT)-PCR, with one primer specific to the 5′ UTR region and the other to the elongation factor 1α coding region, amplifies PTI-1 transcripts from total RNA of various human tumor cell lines and blood samples from prostate carcinoma patients. RT-PCR products with the predicted size and sequence of PTI-1 are detected in RNAs from cell lines of human prostate, breast, and colon carcinomas. This RT-PCR product is shown by Southern blotting and sequence analyses to contain the junction sequence between the 5′ UTR and the coding region of the PTI-1 gene. Furthermore, RT-PCR analysis indicates that the PTI-1 gene is also expressed in prostate carcinoma patient-derived blood samples. On the basis of serial dilution experiments, PTI-1 can detect 1 prostate carcinoma cell in 108 cells not expressing PTI-1 . In this context, PTI-1 represents a sensitive marker for detecting human prostate cancer in the bloodstream. This study confirms the authenticity of the PTI-1 gene and documents its potential clinical utility as a sensitive and specific indicator of prostate cancer progression.

/pdf/human-prostatic-carcinoma-oncogene-pti-1-is-expressed-in-4dwse1uoj3.pdf

Jian Lin

Papers

Induction of differentiation in human promyelocytic HL-60 leukemia cells activates p21, WAF1/CIP1, expression in the absence of p53.

The melanoma differentiation-associated gene mda-6, which encodes the cyclin-dependent kinase inhibitor p21, is differentially expressed during growth, differentiation and progression in human melanoma cells.

Surface-epitope masking and expression cloning identifies the human prostate carcinoma tumor antigen gene PCTA-1 a member of the galectin gene family

Growth Suppression and Toxicity Induced by Caffeic Acid Phenethyl Ester (CAPE) in Type 5 Adenovirus-transformed Rat Embryo Cells Correlate Directly with Transformation Progression

Human Prostatic Carcinoma Oncogene PTI-1 Is Expressed in Human Tumor Cell Lines and Prostate Carcinoma Patient Blood Samples