Several genes encoding ribosomal proteins are over‐expressed in prostate‐cancer cell lines: Confirmation of L7a and L37 over‐expression in prostate‐cancer tissue samples

Abstract

A cDNA library specific for mRNA over-expressed in prostate cancer was generated by subtractive hybridization of transcripts originating from prostatic hyperplasia and cancer tissues. cDNA encoding ribosomal proteins L4, L5, L7a, L23a, L30, L37, S14 and S18 was found to be present among 100 analyzed clones. Levels of ribosomal mRNA were significantly higher at least in one of the prostate-cancer cell lines, LNCaP, DU-145 and PC-3, than in hyperplastic tissue, as determined by slot-blot hybridization. Furthermore, L23a-and S14-transcript levels were significantly elevated in PC-3 cells as compared with those in the normal prostate epithelial cell line PrEC. Generally, dramatic changes in the mRNA content of the ribosomal proteins were not detected, the most evident over-expression being that of L37 mRNA, which was 3.4 times more abundant in LNCaP cells than in hyperplastic prostate tissue. The over-expression of L7a and L37 mRNA was confirmed in prostate-cancer tissue samples by in situ hybridization. Elevated cancer-related expression of L4 and L30 has not been reported, but levels of the other ribosomal proteins are known to be increased in several types of cancers. These results therefore suggest that prostate cancer is comparable with other types of cancers, in that a larger pool of some ribosomal proteins is gained during the transformation process, by an unknown mechanism. Int.

Ribosomal Proteins and Colorectal Cancer

“…The similar results appeared in carcinoma of breast [9], prostate [3], uterine cervix [10], esophagus [11], liver [12] and also in the glioblastoma and multiforme brain tumors [13].…”

“…The dual-function was performed by its different domains [42]. RPS6, a regulator of cell growth, [3] was regulated precisely by extracellular signal which was always disordered in tumor [43][44][45]. RPS6 kinase significantly upregulated in tumors of PTEN mutation, and inhibition of their activity would slowdown the growth of tumors by anti-cancer medicine [46][47].…”

“…Many RPs also fill various roles that are independent of protein biosynthesis, called extraribosomal functions. Some researches revealed that most of RPs just enhanced but were not prerequisite for the protein biosynthesis [3]. The Minute drosophila with RP genes mutation of RP49,RPL9 and RPS13, demonstrated strongly that a quantitative deficiency of RPs could yield abnormal but viable phenotypes [4][5][6].…”

The Comparison of Gene Expression from Multiple cDNA Libraries

“…The genes for S4, L37, and L37a are underexpressed in tumor tissue compared with the normal or hyperplastic cells. This appears to be contrary to the findings of Vaarala et al (1998), who have found that a number of ribosomal mRNAs, including L37, are over-expressed in prostatic cancer cell lines and tumor samples. We do not have any explanation for these discrepancies.…”

Differentially Expressed Genes in Two LNCaP Prostate Cancer Cell Lines Reflecting Changes during Prostate Cancer Progression

“…The gene encoding this protein is overexpressed in a non-metastatic variant of rat rhabdomyosarcoma, SMF-Da (Daigneault et al, 1995). The expression of several other ribosomal proteins is also altered in prostate cancer and prostate cancer cell lines (Vaarala et al, 1998).…”