Ribosomal protein genes are overexpressed in colorectal cancer: isolation of a cDNA clone encoding the human S3 ribosomal protein.

Abstract

We have isolated a cDNA clone encoding the human S3 ribosomal protein from a normal human colon cDNA library. The clone was identified as one of many that detected genes whose level of expression was increased in adenocarcinoma of the colon relative to normal colonic mucosa. Increased levels of the S3 transcript were present in the tumors of all eight patients examined. Moreover, the S3 mRNA was also more abundant in 7 of 10 adenomatous polyps, the presumed precursor of carcinoma. Additional studies demonstrated that increased levels of mRNAs encoding several other ribosomal proteins, including S6, S8, S12, L5, and P0, were present in colorectal tumors and polyps. These results suggest that there is increased synthesis of ribosomes in colorectal tumors and that this increase is an early event in colon neoplasia.

Antisense sequences of the nbl gene induce apoptosis in the human promyelocytic leukemia cell line HL-60

“…23 Although ribosome biogenesis is a common feature of active proliferation, whether it be normal or malignant, the possible involvement of several ribosomal proteins in oncogenesis has been raised by observations of their selectively enhanced expression in various tumors and that such enhancement has no apparent association with proliferative activity. 24,25 Specific ribosomal proteins can also potentially modulate growth by differentially regulating protein synthesis. For example, constitutively expressed ribosomal protein L7 has been suggested to induce apoptosis by specifically blocking synthesis of anti-apoptotic factors.…”

Differential antiproliferative mechanisms of novel derivative of benzimidazo[1,2-α]quinoline in colon cancer cells depending on their p53 status

“…Negative regulation of its expression was shown to induce growth arrest of transformed human cells through both activation of p53 and p53-independent pathways (37), the latter possibly being the case in SW620. Similarly, increased levels of the 40S ribosomal protein SA and 40S ribosomal protein S12 transcripts were found in human colon carcinoma in comparison with adjacent normal colonic epithelium (38,39). Based on their study uncovering increased levels of mRNAs encoding several other ribosomal proteins (P0, S6, S8, and L5) in colorectal tumors and adenomatous polyps, Pogue-Geile et al (39) hypothesized about an increased synthesis of ribosomes in colorectal tumors, which is probably an early event in colon neoplasia.…”

“…Similarly, increased levels of the 40S ribosomal protein SA and 40S ribosomal protein S12 transcripts were found in human colon carcinoma in comparison with adjacent normal colonic epithelium (38,39). Based on their study uncovering increased levels of mRNAs encoding several other ribosomal proteins (P0, S6, S8, and L5) in colorectal tumors and adenomatous polyps, Pogue-Geile et al (39) hypothesized about an increased synthesis of ribosomes in colorectal tumors, which is probably an early event in colon neoplasia. Our findings revealing lowered levels of several ribosomal proteins in SW620 put forward the possibility that quinoline derivative interferes with ribosome biogenesis in these cells leading to their reduced proliferation ability.…”

Identification of a 170-kDa protein over-expressed in lung cancers

“…It has been shown that over-expression of factors of translation machinery such as elongation factor EF1α (Tatsuka et al, 1992), initiation factors eIF4E (Lazaris-Karatzas et al, 1990), eIF4G (Fukuchi-Shimogori et al, 1997), eIF2α (Donze et al, 1995), and ribosomal protein S3a (Kho et al, 1996), affect cell growth. Expression of eIF4E (De Benedetti and Harris, 1999), the p48 of eIF3 (Asano et al, 1997b), EF1γ (Chi et al, 1992;Lew et al, 1992), and S3a (Pogue-Geile et al, 1991) has also been found deregulated in tumours.…”