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Recent studies have demonstrated that antineoplastic activity of Cox-2 inhibitors may depend on targets other than Cox: among those, nuclear factor kappaB (NFkappaB) seems the most promising. Although preclinical studies have suggested that aspirin and Cox-2 inhibitors may influence the progression of lung cancer, the molecular mechanisms of these protective effects in this tumor type has not been fully elucidated. We investigated the effects of celecoxib and aspirin in the induction of apoptosis and in the ability to activate NFkappaB in three non-small cell lung cancer cell lines. Apoptosis was evaluated by FACS, caspase activation assay and expression of apoptosis-related genes by RT-PCR, while NFkappaB activation was assessed by immunofluorescence. No apoptotic response was observed after treatment with both high and low dose of celecoxib. Nevertheless, celecoxib at both concentrations induced a strong NFkappaB activation, with increased expression of NFkappaB-dependent genes, such as bcl-2, bcl-XL and survivin. Similarly, aspirin at both concentrations did not induce any apoptotic response, but activated NFkappaB in a dose-dependent manner. This study supports the hypothesis that NFkappaB activation is an important effect of NSAIDs in lung cancer, leading to apoptosis resistance. This effect of both aspirin and celecoxib may be considered undesirable in lung cancer chemoprevention.

Tenascin C has been recently suggested as a tumor marker, however, its levels in serum has been evaluated only in patients with head and neck cancer and melanoma. In this study, we investigated Tenascin C expression in blood samples from colorectal and bladder cancer patients, compared to that of epidermal growth factor receptor (EGFR), a known circulating tumor marker in these cancer types. RT-PCR specific for Tenascin C and EGFR was performed on RNAs extracted from blood samples of 60 patients affected by colon or bladder cancer. We then investigated the statistical association between Tenascin C, EGFR expression and disease-free survival using the Kaplan-Meier method. Furthermore, in order to select which variable between EGFR and Tenascin C was the most predictive for recurrence, a Cox model for proportional risk was applied. Among all patients analysed, a significantly higher disease-free time was found in the group negative for both EGFR and Tenascin C expression; EGFR expression was significantly correlated to disease progression in stages III and IV, whereas in all patients with stage I and II disease Tenascin C correlated better with prognosis. Negative expression of both EGFR and Tenascin C identifies a group of patients with poor tendency to disease recurrence and longer relapse-free time. While Tenascin C expression seems to influence prognosis in patients with low-stage disease, EGFR appears a marker of worse prognosis in patients with high-staged tumors.

Expression of genes such as cytokeratin 19 (CK19), cytokeratin 20 (CK20) and epidermal growth factor receptor (EGFR) has been investigated at mRNA level in peripheral blood of carcinoma patients to detect the presence of circulating tumor cells (CTC). We performed this study because recent literature emphasizes that the importance of CK19, 20 and EGFR mRNAs in CTC as prognostic factors remains unclear especially for breast, head and neck and colon cancer patients. Reverse transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot hybridization was performed in blood samples from 47 subjects (12 colorectal, 15 head and neck and 20 breast carcinoma patients), as well as in 35 healthy donors. The CK19 expression was found in 36/47 patients (9 colorectal, 9 head and neck and 18 breast cancer), two patients (one affected by colorectal and one by head and neck cancer) were positive for CK20 whereas EGFR was found expressed in 9 patients (3 colorectal, 5 head and neck and one breast cancer). Seven of 35 and 4/35 healthy donors displayed positivity for the expression of CK19 and CK20 genes respectively, whereas no EGFR mRNA was found in this group. The correlation of the detection of CTC in peripheral blood with progression of the disease in a follow-up period of 40 months did not show any prognostic value to the presence of mRNAs of these biomarkers in blood. We believe that research should be addressed, at least for breast cancer, to the identification of occult metastases in sentinel lymph nodes, such as recently performed in melanoma patients.