Preferential involvement of chromosome 11 as add(11)(p15) in ovarian cancer: is it a common cytogenetic abnormality in cancer?

Tumor spreading to the contralateral ovary in bilateral ovarian carcinoma is a late event in clonal evolution

Cancer of the ovary is bilateral in 25%. Cytogenetic analysis could determine whether the disease in bilateral cases is metastatic or two separately occurring primary tumors, but karyotypic information comparing the two cancerous ovaries is limited to a single report with 11 informative cases. We present a series of 32 bilateral ovarian carcinoma cases, analyzed by karyotyping and high-resolution CGH. Our karyotypic findings showed that spreading to the contralateral ovary had occurred in bilateral ovarian cancer cases and that it was a late event in the clonal evolution of the tumors. This was confirmed by the large number of similar changes detected by HR-CGH in the different lesions from the same patient. The chromosomal bands most frequently involved in structural rearrangements were 19p13 (n = 12) and 19q13 (n = 11). The chromosomal bands most frequently gained by both tumorous ovaries were 5p14 (70%), 8q23-24 (65%), 1q23-24 (57%), and 12p12 (48%), whereas the most frequently lost bands were 17p11 (78%), 17p13 (74%), 17p12 (70%), 22q13 (61%), 8p21 and 19q13 (52%), and 8p22-23 (48%). This is the first time that 5p14 is seen gained at such a high frequency in cancer of the ovary; possibly oncogene(s) involved in bilateral ovarian carcinogenesis or tumor progression may reside in this band.

Human PAF complexes in endocrine tumors and pancreatic cancer

The human RNA polymerase II-associated factor (hPAF) complex is comprised of five subunits that include hPaf1, parafibromin, hLeo1, hCtr9 and hSki8. This multifaceted complex was first identified in yeast (yPAF) and subsequently in Drosophila and humans. Recent advances in the study on hPAF have revealed various functions of the complex in humans that are similar to yPAF, including efficient transcription elongation, mRNA quality control and cell cycle regulation. A major component of the hPAF complex, hPaf1, is amplified and overexpressed in pancreatic cancer. The parafibromin subunit of the hPAF complex is a product of the hereditary hyperparathyroidism type 2 (HRPT-2) tumor-suppressor gene, which is mutated in the germ line of hyperparathyroidism-jaw tumor patients. This review evaluates the role of the hPAF complex and its individual subunits in endocrine and pancreatic cancers. It focuses on the functions of the hPAF complex and its individual subunits and dysregulation of the complex, thus providing an insight into its potential involvement in the development of endocrine cancers and other tumor types.