[Influence on cell proliferation by small interfering RNA of Cyclin Y expression in laryngeal cancer cells].

OBJECTIVE: The effects of lentivirus-mediated suppression of Cyclin Y (CCNY) expression on the proliferation of laryngeal cancer cells were investigated in vitro. METHODS: The lentivirus vectors containing a small hairpin RNA (shRNA) to target CCNY were constructed.Hep-2 cells were divided into the following two experimental groups:the negative control group (control lentivirus infected cells) and CCNY knockdown group (CCNY shRNA-expressing lentivirus infected cells). After Hep-2 cells were infected, Real-time PCR was used to measure CCNY expression. The influence of CCNY on the proliferation of laryngeal cancer cells were assessed using MTT and colony formation experiments.Each experiment was performed in triplicate and repeated three times. RESULTS: Lentiviruses expressing shRNA against CCNY were constructed and Hep-2 cells were infected with above mentioned lentivirus at MOI (Multiplicity of infection) of 120.Real-time PCR analysis showed that the mRNA expression of CCNY in Hep-2 cells in the knockdown group was significantly decreased (P < 0.05); the mRNA level of CCNY was 75.3% lower in the si-CCNY group than in the si-CTRL group. After 5 days of lentiviral infection, the cell viability was significantly lower in cells infected with the CCNY-shRNA lentivirus compared to cells infected with the control lentivirus following a 6-day incubation. The colony number was decreased by 60% in Hep-2 cells infected with the CCNY-shRNA-lentivirus infected cells following a 10-day incubation. CONCLUSIONS: The results suggested that lentivirus-mediated downregulation of CCNY expression decreased the proliferation and growth potency of laryngeal cancer cells.Lentiviruses delivering shRNA against CCNY may be a promising tool for laryngeal cancer therapy.

[Relationship of alcohol drinking and tea consumption with the risk of nasopharynx cancer among Chinese population: a meta-analysis].

OBJECTIVE: To evaluate the relationship and strength of association for alcohol drinking and tea consumption with the riskS of nasopharynx cancer among Chinese population so as to provide control rationales for nasopharynx cancer in China. METHODS: A systematic search of 3 Chinese electronic databases (CNKI, VIP, Wanfang) and 3 English databases (Pubmed, ScienceDirect and SpringerLink) up to March 2013 was performed. Two reviewers independently conducted the literature search, examined eligibility and performed data extraction and quality evaluations. Pooled odd ratio (OR) value and 95%CI value were calculated with random-effects model weighted with inverse of variances. RESULTS: A total of 14 studies (including 3 cohort and 11 case-control) involving 6559 cases of nasopharynx cancer and 10 567 controls from 6 provinces were included. The pooled OR between alcohol drinking and risks of nasopharynx cancer was 1.12 (95%CI: 0.98-1.26; I(2) = 44.5%, P = 0.037). Compared with the non-drinkers, the risks of nasopharynx cancer for regular drinkers and occasional drinkers were 1.18 (95%CI: 1.00-1.38; I(2) = 0.0%, P = 0.578) and 0.76 (95%CI: 0.65-0.89; I(2) = 33.4%, P = 0.212). And the association of tea consumption with the risks of nasopharynx cancer was 0.53 (95%CI: 0.43-0.60; I(2) = 17.9%, P = 0.301). CONCLUSIONS: In China, occasional alcohol drinking may decrease the risks of nasopharynx cancer while regular drinking elevates the risks. And there is significantly protective effect for tea consumption on the risks of nasopharynx cancer.