Ribosomal biogenesis is correlated with cell cycle, cell proliferation, cell growth and tumorigenesis. Some oncogenes and tumor suppressors are involved in regulating the formation of mature ribosome and affecting the ribosomal biogenesis. In previous studies, the mitochondrial ribosomal protein L41 was reported to be involved in cell proliferation regulating through p21(WAF1/CIP1) and p53 pathway. In this report, we have identified a mitochondrial ribosomal protein S36 (mMRPS36), which is localized in the mitochondria, and demonstrated that overexpression of mMRPS36 in cells retards the cell proliferation and delays cell cycle progression. In addition, the mMRPS36 overexpression induces p21(WAF1/CIP1) expression, and regulates the expression and phosphorylation of p53. Our result also indicate that overexpression of mMRPS36 affects the mitochondrial function. These results suggest that mMRPS36 plays an important role in mitochondrial ribosomal biogenesis, which may cause nucleolar stress, thereby leading to cell cycle delay.

Background: The Solanum species have been used for the treatment of warts, tumor and cancer in folk medicine. The S. incanum extract is an important traditional Chinese medicine in Taiwan since 1973. The purpose of the present study was to evaluate the efficacy and safety of Solanum incanum (synonym: Solanum undatum) extract (SR-T100), a water-soluble product primarily composed of alkaloid solamargine, for the treatment of human condyloma and to study the possible underlying anti-condyloma mechanisms.