Operculina turpethum extract inhibits growth and proliferation by inhibiting NF-κB, COX-2 and cyclin D1 and induces apoptosis by up regulating P53 in oral cancer cells.

OBJECTIVES: Herbal drugs are popularly emerging as complementary and alternative medicines in cancer patients because of their cost effectiveness and minimal side-effects. The extract of Operculina turpethum (OT) is known to have antipyretic, anti-inflammatory and purgative properties. Since it is popularly known have antiinflammatory activity, we investigated its anti-tumor activity on four oral squamous cell carcinoma cell lines (OSCC) namely, (SCC-4, KB, SCC-9 and SCC-25). DESIGN: Antitumor activities of Operculina turpathum extract (OTE) was investigated by MTT and clonogenic assay, effect on cell cycle and apoptosis induction by Annexin-V/propidium iodide (PI) staining and flow cytometry and invasive potential of the tumor was determined by matrigel assay. The expression of various proteins involved in these mechanisms was analysed by western blotting. RESULTS: OTE specifically inhibited the growth and colony formation of OSCC cells in a dose-dependent manner via inhibiting NF-κB and its downstream target COX-2. It further arrested cell cycle at G0/G1 phase by inhibiting cyclin-D1 and induced early apoptosis by up-regulating P53 in OSCC cells. It also limits the invasion capacity of OSCC cells by up to 55-60%. CONCLUSIONS: OTE shows antitumor activities in OSCC cells by inhibiting NF-κB, COX-2 and cyclin D1 and upregulation of p53 expression. It may be developed as a safe and promising alternative chemopreventive/chemotherapeutic agent for oral cancer.

Abnormal expression of PI3K isoforms in patients with tobacco-related oral squamous cell carcinoma.

BACKGROUND: The phosphatidylinositol 3-kinase (PI3K) signaling regulates several cellular functions such as motility, proliferation, angiogenesis and survival. METHODS: Since there is no information on expression of PI3K isoforms in oral cancer, we studied the expression of different isoforms of PI3K (p110α, p110γ, PI3K-C2, Vps34p and p85α) in tumor samples and PBMC by RT and q-RTPCR and serum levels of PI3K p110α by SPR and ELISA techniques in 108 patients with tobacco-related oral squamous cell carcinoma (OSCC) and 46 normal subjects. RESULTS: We observed significantly higher PI3K p110α (p<0.0001) and lower (p<0.0001) vesicular sorting protein 34p (Vps34p) mRNA both in PBMC and tissue samples of oral cancer patients as compared to the normal controls. Other PI3K isoforms did not show such change. Circulating PI3K p110α levels were higher in patients (p<0.0001) as compared to healthy subjects, the SPR data showed direct correlation with advancing stage of the disease. PI3K p110α was overexpressed in tumor samples but not in the normal buccal mucosa. CONCLUSIONS: Upregulation of circulating PI3K p110α isoform and its direct correlation with increasing tumor load in OSCC patients indicates that it may be a significant prognostic indicator and a suitable target for therapeutic/chemo-preventive strategies for tobacco-related OSCC.

Functional genetic variants of TGF-ß1 and risk of tobacco-related oral carcinoma in high-risk Asian Indians.

Transforming growth factor (TGF)-ß1, the most abundant isoform of TGF-ß have been implicated in various stages of carcinogenesis such as epithelial to mesenchymal transition, enhanced expression of metalloproteases, down-regulation of cellular adhesion molecule, increased tumor motility and angiogenesis as well as local and systemic immunosuppression leading to a more aggressive and metastatic behavior. We assessed the association of TGF-ß1 functional genetic polymorphisms at codon 10 (869 T>C) and 25 (915 G>C) of exon 1 in 140 patients with tobacco-related oral squamous cell carcinoma (OSCC) and 120 normal subjects by PCR-RFLP. The frequency of 869 CC genotype and C allele were significantly higher in patients as compared to controls (P(c), 0.024 and 0.0004, respectively) while no significant difference was observed in the frequency of 915 CC genotype and C allele. In logistic regression analysis CC genotype (OR, 3.87; 95% CI, 1.78-8.41) and C allele (OR, 2.20; 95% CI 1.51-3.20) appeared as susceptible while TT genotype and T allele as protective. In addition C(869)-C(915) haplotype with OR of 2.48 at 95% CI, 1.51-4.06 significantly (P=0.0003) increased the risk of tobacco-related OSCC in Asian Indians.

Functional variants of COX-2 and risk of tobacco-related oral squamous cell carcinoma in high-risk Asian Indians.

We assessed the association of COX-2 polymorphisms at promoter sites -1195, -765 and at 3'UTR (8473) in 193 patients with oral squamous cell carcinoma (OSCC) and 137 normal subjects by PCR-RFLP. Although no significant difference was observed in the frequency of COX-2 -1195G>A, -765G>C and 8473C>T single nucleotide polymorphisms (SNPs) between patients and controls, COX-2 -1195G/A genotype showed higher while -765G/C and 8473C/T showed lower prevalence in patients as compared to normal subjects. Logistic regression analysis of these three polymorphisms revealed a quantitative risk associated with -1195G>A SNP (OR 3.07 at 95%CI) while -765G>C and 8473C>T appeared to be protective. Results of the present study indicate that these three functional variants in the COX-2 regulatory region may contribute to risk modification of tobacco-related oral squamous cell carcinoma in Asian Indians.