Rb2/p130

This protein is a member of the retinoblastoma gene family of tumour suppressor genes. It has a growth-suppressive action on the G0/G1 phases of the cell cycle. It has been mapped to 16q12.2, a locus frequently altered in neoplasms, including those breast, ovarian, hepatic, prostatic and endometrial carcinomas. There is evidence of the involvement of Rb2/p130 in the pathogenesis and progression of lung cancers and mesotheliomas. There is progressive decrease in expression from hyperplastic endometrium through atypical hyperplasia to carcinoma of increasing grade. It is a strong predictor of outcome in endometrial carcinomas, choroidal melanomas and lymphomas. Staining is nuclear.

Rb2 shows a progressive decrease in expression from hyperplastic endometrium through atypical hyperplasia to carcinoma of increasing grade1:

		negative	1% to 50% of nuclei	>50% of nuclei	average % of nuclei staining
proliferative phase		0/18	9/18	9/18	67%
secretory phase		6/18	5/18	7/18	38%
hyperplasia without atypia		1/18	7/18	10/18	60%
atypical hyperplasia		8/18	3/18	7/18	25%
endometrial carcinoma	grade 1	1/11	10/11	0/11	32%
	grade 2	1/10	9/10	0/10	23%
	grade 3	5/9	4/9	0/9	8%
	overall	7/30	23/30	0/30	22%

References

1Susini, T., Massi, D., Paglierani, M., Masciullo, V., Scambia, G., Giordano, A., Amunni, G., Massi, G., Taddei, G. L. Expression of the retinoblastoma-related gene Rb2/p130 is downregulated in atypical endometrial hyperplasia and adenocarcinoma Human Pathol 2001;32:360-367.

This page last revised 6.11.2001.