Overlapping substrate specificities and tissue distribution of cytochrome P450 3A and P-glycoprotein: implications for drug delivery and activity in cancer chemotherapy.

The clonal composition of human colorectal tumors was studied by means of restriction fragment length polymorphisms (RFLPs). First, X-linked RFLPs were used to examine the pattern of X chromosome inactivation in colorectal tumors of females. All 50 tumors examined showed monoclonal patterns of X chromosome inactivation; these tumors included 20 carcinomas as well as 30 adenomas of either familial or spontaneous type. Second, RFLPs of autosomes were used as clonal markers to detect the somatic loss or gain of specific chromosomal sequences in colorectal tumors. Among other changes, it was found that somatic loss of chromosome 17p sequences occurred in over 75 percent of the carcinomas examined, but such loss was rare in adenomas. These data support a monoclonal origin for colorectal neoplasms, and suggest that a gene on the short arm of chromosome 17 may be associated with progression from the benign to the malignant state.

http://science.sciencemag.org/content/sci/238/4824/193.full.pdf

Clonal analysis of human colorectal tumors

Cancer may be defined as a progressive series of genetic events that occur in a single clone of cells because of alterations in a limited number of specific genes: the oncogenes and tumor suppressor genes. The association of consistent chromosome aberrations with particular types of cancer has led to the identification of some of these genes and the elucidation of their mechanisms of action. Consistent chromosome aberrations are observed not only in rare tumor types but also in the relatively common lung, colon, and breast cancers. Identification of additional mutated genes through other chromosomal abnormalities will lead to a more complete molecular description of oncogenesis.

https://science.sciencemag.org/content/sci/254/5035/1153.full.pdf

Chromosome aberrations and cancer

Morbidity in Turner syndrome.

Chromosomes in Ewing's sarcoma. I. An evaluation of 85 cases and remarkable consistency of t(11;22)(q24;q12)

A method combining an enzymatic technique and short term culture was applied to 27 tumor tissues from 22 patients with nonfamilial renal cell carcinoma in order to establish the chromosome changes in these tumors. Chromosome analyses were successfully carried out in quinacrine mustard-Hoechst 33258 and G-banded preparations of 14 tumors from 12 patients, including 2 cases in which established cell lines were obtained after 43 and 64 days in culture and maintained for 25 and 30 passages in an in vitro system, respectively. The modal chromosome numbers ranged from 38–46 in 11 samples, involving chromosomes in structural and numerical changes and 72 chromosomes in one case, with the remaining 2 samples showing a variety of chromosome numbers. Banding analysis revealed 45 clonal aberrations in 11 tumor samples from 10 patients and nonclonal aberrations in the remaining 3 samples from 2 of the patients. Rearrangements of chromosome 3 were observed in 12 tumors, with the breakpoints on this chromosome almost totally clustered from p11 to p21. In one case both primary and metastatic tumors were studied, and an isochromosome for the long arm of chromosome 1 was observed as clonal in origin in the metastatic tissue. Two cases showed nonclonal changes. The remaining case had one clonal abnormality, i.e. , deletion of 6q. Of the remaining 33 clones, chromosomes 1, 2, 6, 11, and 17 were frequently involved. These results suggest that renal cell carcinoma may be cytogenetically classified into 3 categories: ( a ) tumors with changes of chromosome 3; ( b ) tumors with other clonal aberrations; and ( c ) tumors without clonal changes. Rearrangements of chromosome 3 may be possibly associated with the genesis and/or progression of renal cell carcinoma.

Cytogenetic Studies of Tumor Tissue from Patients with Nonfamilial Renal Cell Carcinoma

An analysis of chromosome aberrations in human tumors was performed in 29 cases of soft tissue sarcoma. The tumor tissues were disaggregated with collagenase and the cells cultured for 2-3 days. Analyzable metaphases were obtained in 15 cases, 4 of which showed only normal karyotypes. The remaining 11 tumors showed various numerical and structural abnormalities in their karyotypes: 8 tumors were near-diploid and the remaining 3 were near-triploid. G- and Q-banding analyses revealed clonal abnormalities in the 11 cases with the presence of marker chromosomes; 15 different chromosomes were involved in chromosome rearrangements, chromosomes 1 and 2 being the most frequently affected. Because of the heterogeneity of the tumor group investigated (neurogenic sarcoma, 2 liposarcomas, neurofibrosarcoma, synovial cell sarcoma, fibrosarcoma, mesothelioma, leiomyosarcoma, rhabdomyosarcoma, Ewing's sarcoma, and hemangiopericytoma), it was impossible to reach any conclusion on the specificity of the cytogenetic abnormalities for a particular tumor type.

Hisako Ochi

Papers

Cytogenetic Studies of Tumor Tissue from Patients with Nonfamilial Renal Cell Carcinoma

Chromosome Changes in Soft Tissue Sarcomas

Cytogenetic studies in primary gastric cancer.

Possible specific chromosome changes in large bowel cancer.

Trisomy X as a possible initial chromosome change in a gastric cancer.