ABSTRACT
OBJECTIVE: Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1), serine/arginine-rich splicing factor 1 (SRSF1), and SRSF3 are splicing regulators associated with oncogenesis. However, the alterations of SF proteins and their diagnostic values in cervical cancer are unclear. To apply SFs clinically, effective marker selection and characterization of the target organ properties are essential. MATERIALS AND METHODS: We concurrently analyzed HNRNPA1, SRSF1, SRSF3, and the conventional tumor markers squamous cell carcinoma antigen (SCCA) and carcinoembryonic antigen (CEA) in cervical tissue samples (n = 127) using semiquantitative immunoblotting. In addition, we compared them with p16 (cyclin-dependent kinase inhibitor 2A [CDKN2A]), which has shown high diagnostic efficacy in immunohistochemical staining studies and has been proposed as a candidate protein for point-of-care screening biochemical tests of cervical neoplasia. RESULTS: HNRNPA1, higher molecular weight forms of SRSF1 (SRSF1-HMws), SRSF3, CEA, and p16 levels were higher (P < 0.05) in cervical carcinoma tissue samples than in nontumoral cervical tissue samples. However, the levels of SRSF1-Total (sum of SRSF1-HMws and a lower molecular weight form of SRSF1) and SCCA, a commonly used cervical tumor marker, were not different between carcinoma and nontumoral tissue samples. In paired sample comparisons, HNRNPA1 (94%) showed the highest incidence of up-regulation (carcinoma/nontumor, >1.5) in cervical carcinoma, followed by p16 (84%), SRSF1-HMws (69%), SRSF3 (66%), CEA (66 %), SCCA (32%), and SRSF1-Total (31%). HNRNPA1 (92%) and p16 (91%) presented the two highest diagnostic accuracies for cervical carcinoma, which were superior to those of SRSF3 (75%), SRSF1-HMws (72%), CEA (72%), SCCA (59%), and SRSF1-Total (55%). CONCLUSIONS: Our results identified that HNRNPA1 is the best diagnostic marker among the SFs and conventional markers given its excellent diagnostic efficacy for cervical carcinoma, and it has a p16-comparable diagnostic value. We suggest that HNRNPA1 is an additional effective target protein for developing cervical cancer detection tools.
Subject(s)
Biomarkers, Tumor/analysis , Heterogeneous Nuclear Ribonucleoprotein A1/analysis , Uterine Cervical Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Female , Heterogeneous Nuclear Ribonucleoprotein A1/genetics , Heterogeneous Nuclear Ribonucleoprotein A1/metabolism , Humans , Immunoblotting , Middle Aged , Serine-Arginine Splicing Factors/analysis , Serine-Arginine Splicing Factors/genetics , Serine-Arginine Splicing Factors/metabolism , Up-Regulation , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/metabolismABSTRACT
Statins, HMG-CoA reductase inhibitors have been studied for their antiproliferative and proapototic effects. Recently, statin-induced apoptosis has been associated with down-regulation of survivin expression in cancer cells. However, the mechanism of deregulated survivin by simvastatin on lung cancer is still unclear. Herein, we demonstrated that simvastatin induced caspase-dependent apoptosis in A549 lung cancer cells. Simvastatin also resulted in a decrease in the expression of phosphorylated Akt. In addition, simvastatin effectively down-regulated survivin mRNA and protein, but not cIAP-1 and cIAP-2. The combination of simvastatin and 10 µM LY294002 (non-toxic dose) augmented apoptosis significantly, as evidenced by cleavage of PARP. The immunoreactive band of survivin was markedly decreased in cells treated with 50 µM LY294002 (toxic dose) as well as by the combination of simvastatin and 10 µM LY294002. Moreover, survivin down-regulation by RNA interference induced apoptosis accompanied by an increase in hypodiploid DNA content. Taken together, these data suggest that the anti-cancer effect of simvastatin via induction of apoptosis is related to Akt signaling dependent down-regulation of survivin in lung cancer A549 cells.
