Cribado del carcinoma escamoso de esófago en población de riesgo

Induced photo-cytotoxicity on prostate cancer cells with the photodynamic action of toluidine Blue ortho

BACKGROUND

Photodynamic therapy (PDT) has become an advantageous therapeutic approach for the treatment of select cancers and microbial infections. PDT generates toxic reactive oxygen species as an end product of the interaction between the photosensitizer and light with an appropriate wavelength. Toluidine blue ortho is a photosensitizer that is commonly used in the photodynamic treatment of bacterial infection and a promising photosensitizer for cancer treatment. This study aims to evaluate the potential photo-cytotoxicity of toluidine blue ortho-mediated photodynamic therapy on PC-3 prostate cancer cells.

METHODS

In this study toluidine blue ortho-mediated photodynamic therapy was assessed on PC-3 cancer cells with various photosensitizer concentrations and light energy densities of the 655-nm diode laser. MTT analysis was used for the determination of the cytotoxicity on the cells and viability/cytotoxicity assay was used for live/dead cell staining after the applications. The mechanism of this application was further analyzed with the determination of intracellular reactive oxygen species and nitric oxide release.

RESULTS

The light applications and the photosensitizer alone did not inhibit the cell viability of PC-3 cells. 20 J/cm² laser energy density together with 100 μM photosensitizer concentration resulted in maximum cancer cell death with a rate of approximately 89 %. The level of intracellular reactive oxygen species increased with the increasing parameters of the applications that resulted in more cell death.

CONCLUSION

This study showed the successful anticancer activity of toluidine blue ortho upon irradiation with 655 nm of laser light against PC-3 cancer cells and it was mediated with the production of reactive oxygen species.

Genetic polymorphisms in cytochrome P4502E1, alcohol and aldehyde dehydrogenases and the risk of esophageal squamous cell carcinoma in Gansu Chinese males

AIM: To evaluate the association between genetic polymorphisms in CYP2E1, ALDH2 and ADH1B and the risk of esophageal squamous cell carcinoma (ESCC) in a high risk area of Gansu Province, in Chinese males.

METHODS: A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYP2E1*c1/*c2, ALDH2*1/*2 and ADH1B *1/*1 genotypes). A total of 80 esophageal cancer cases and 480 controls were recruited.

RESULTS: Compared with controls, cases had a greater prevalence of heavier alcohol consumption (53.8% vs 16.2%) and a higher proportion of alcohol drinkers with > 30 drink-years (28.8% vs 13.5%). Heavier alcohol consumption and alcohol drinking with > 30 drink-years increased the risk of ESCC, with ORs (95% CI) of 3.20 (1.32-9.65) and 1.68 (0.96-3.21). CYP2E1 (*c1/*c1), ALDH2 (*1/*2) and ADH1B (*1/*1) genotype frequencies were higher among patients with squamous cell carcinomas, at a level close to statistical significance (P = 0.014; P = 0.094; P = 0.0001 respectively). There were synergistic interactions among alcohol drinking and ALDH2, ADH1B and CYP2E1 genotypes. The risk of the ESCC in moderate-to-heavy drinkers with an inactive ALDH2 encoded by ALDH2*1/*2 as well as ADH1B encoded by ADH1B *1/*1 and CYP2E1 encoded by CYP2E1 *c1/*c1 was higher than that in the never/rare-to-light drinkers with an active ALDH2 (*1/*1 genotype) as well as ADH1B (*1/*2 + *2/*2) and CYP2E1 (*c1/*c2 + *c2/*c2) genotypes, with a statistically significant difference; ORs (95% CI) of 8.58 (3.28-22.68), 27.12 (8.52-70.19) and 7.64 (2.82-11.31) respectively. The risk of the ESCC in moderate-to-heavy drinkers with ALDH2 (*1/*2) combined the ADH1B (*1/*1) genotype or ALDH2 (*1/*2) combined the CYP2E1 (*c1/*c1) genotype leads to synergistic interactions, higher than drinkers with ALDH2 (*1/*1) + ADH1B (*1/*2 + *2/*2), ALDH2 (*1/*1) + CYP2E1 (*c1/*c2 + *c2/*c2) respectively , ORs (95% CI) of 7.46 (3.28-18.32) and 6.82 (1.44-9.76) respectively. Individuals with the ADH1B combined the CYP2E1 genotype showed no synergistic interaction.

CONCLUSION: In our study, we found that alcohol consumption and polymorphisms in the CYP2E1, ADH1B and ALDH2 genes are important risk factors for ESCC, and that there was a synergistic interaction among polymorphisms in the CYP2E1, ALDH2 and ADH1B genes and heavy alcohol drinking, in Chinese males living in Gansu Province, China.

De novo esophageal neoplasia after liver transplantation

The purpose of the study was to determine the incidence, risk factors, treatment, and influence on survival of patients with de novo esophageal cancer after liver transplantation (LT). From 1988 to 2006, 1,926 patients underwent LT in our institution. A total of 9 patients (0.5%) developed a de novo esophageal cancer and 1 patient a cancer of the cardia (0.05%). A retrospective analysis was performed to reveal underlying diseases, timeframes between LT and appearance of cancer, predisposing factors, cancer therapy, complications, immunosuppressive regimens, and survival. Of our 10 patients, 7 (70%) suffered from esophageal squamous cell carcinoma (SCC) and 3 patients (30%) developed an adenocarcinoma, including the patient with cancer of the cardia. A total of 9 patients were transplanted due to alcoholic cirrhosis; 1 patient suffered from hepatocellular carcinoma in nonA-nonB hepatitis-related cirrhosis. Median time to tumor diagnosis was 51 months after transplantation. A total of 5 patients were treated conservatively with combined radiochemotherapy and 5 underwent surgical resection. Patients with radiochemotherapy showed a mean survival of 14.8 months vs. 24.8 months for the patients of the surgery group. No major postoperative complication has been observed. A total of 2 patients of the surgery group are still alive after a follow-up of 15 and 89 months. In conclusion, de novo esophageal and cancer of the cardia after LT is a rare event. In spite of immunosuppression, no increased complication rate has been observed. Patients may have a survival benefit from surgical resection.