These results indication that pure and impure diosgenin prevents telomerase activity by down regulation of the hTERT gene expression in A549 lung cancer cell line, with the difference that pure compound is more effective than another.
Recently, a number of case-control studies have been carried out to investigate the relationship between the rs2736100 polymorphism in TERT and genetic susceptibility to lung cancer.
However, the joint effect of TERT and CLPTM1L variants increased the risk of lung cancer, especially squamous cell carcinoma, with an adjusted OR of 3.274.
The ectopic overexpression of CPSF4 upregulated the hTERT promoter-driven report gene expression and activated the endogenous hTERT mRNA and protein expression and the telomerase activity in lung cancer cells and normal lung cells.
Our findings, combined with previous studies, suggest that polymorphisms in the TERT gene contribute to the risk for lung cancer in the Chinese Han population.
In the logistic regression analysis, TERT-rs2853669, rs2736108, and CLPTM1L-rs31490 were significant associated with increased risk of lung cancer (OR = 1.46, 95% CI = 1.22-1.75; OR = 1.22, 95% CI = 1.00-1.49 and OR = 1.74, 95% CI = 1.35-2.23 under additive model, respectively).
We identified one novel variant at the level corrected for multiple comparisons (rs2741354 in EPHX2 at 8p21.1 with p value = 7.4 × 10(-6)), and confirmed the associations between TERT (rs2736100) and the HLA region and lung cancer risk.
Single-nucleotide polymorphisms rs421629 on 5p15.33 and rs1948, rs660652, rs8040868 and rs2036527 on 15q25.1, previously identified as lung cancer risk or nicotine-addiction modifiers, were associated with tumor DNA methylation levels in the promoters of TERT and CHRNB4 (P<0.001), respectively, in two independent sample sets (n=82; n=150).
These results suggest that genetic variants in the TERT-CLPTM1L gene may predispose individuals to be susceptible to LC, particularly NSCLC, in the Chinese population.
After the 2nd stage validation (975 cases versus 1022 controls), the study clarified the association that rs2736100 of the TERT gene conferred the highest significant risk of lung cancer (P=4×10(-3) in the 1st stage association, P=4×10(-4) in the 2nd stage validation, and P=1×10(-5), odds ratio=1.24 in the combined population).
Longer telomere length in peripheral white blood cells is associated with risk of lung cancer and the rs2736100 (CLPTM1L-TERT) polymorphism in a prospective cohort study among women in China.
We conducted a search of case-control studies on the association of TERT with susceptibility to lung cancer in PubMed, EMBASE, ISI Web of Science, Wanfang database in China, and Chinese National Knowledge Infrastructure (CNKI) databases.
A common genetic variant, telomerase reverse transcriptase (TERT) rs2736098, was recently reported to be associated with lung cancer risk in Caucasians.
Human telomerase reverse transcriptase (hTERT) gene amplification was detected in pleural effusions of patients with lung cancer (n = 69) and in patients with benign lung disease (n = 46) when using a quantitative polymerase chain reaction (qPCR) technique.
Genetic factors included six variants implicated in a previous a genome-wide association study (GWAS) of NPC and three variants residing near the CHRNA3 and TERT genes that were linked to lung cancer risk in Asian populations.
The combined analyses identified six well-replicated SNPs with independent effects and significant lung cancer associations (P < 5.0 × 10(-8)) located in TP63 (rs4488809 at 3q28, P = 7.2 × 10(-26)), TERT-CLPTM1L (rs465498 and rs2736100 at 5p15.33, P = 1.2 × 10(-20) and P = 1.0 × 10(-27), respectively), MIPEP-TNFRSF19 (rs753955 at 13q12.12, P = 1.5 × 10(-12)) and MTMR3-HORMAD2-LIF (rs17728461 and rs36600 at 22q12.2, P = 1.1 × 10(-11) and P = 6.2 × 10(-13), respectively).