Selenium-containing analogs of SAHA induce cytotoxicity in lung cancer cells.

Cancer therapy has moved beyond conventional chemotherapeutics to more mechanism-based targeted approaches. Studies demonstrate that histone deacetylase (HDAC) is a promising target for anticancer agents. Numerous, structurally diverse, hydroxamic acid derivative, HDAC inhibitors have been reported and have been shown to induce growth arrest, differentiation, autophagy, and/or apoptotic cell death by inhibiting multiple signaling pathways in cancer cells. Suberoylanilide hydroxamic acid (SAHA) has emerged as an effective anticancer therapeutic agent and was recently approved by the FDA for the treatment of advanced cutaneous T-cell lymphoma. In our previous study, we reported the development of the novel, potent, selenium-containing HDAC inhibitors (SelSA-1 and SelSA-2). In this study, the effects of SelSA-1 and SelSA-2 on signaling pathways and cytotoxicity were compared with the known HDAC inhibitor, SAHA, in lung cancer cell lines. After 24 h of treatment, SelSA-1 and SelSA-2 inhibited lung cancer cell growth to a greater extent than SAHA in a dose-dependent manner with IC(50) values at low micromolar concentrations. SelSA-1 and SelSA-2 inhibited ERK and PI3K-AKT signaling pathways while simultaneously increasing in autophagy in A549 cells in a time dependent manner. This preliminary study demonstrates the effectiveness of the selenium-containing analogs of SAHA, SelSA-1, and SelSA-2, as HDAC inhibitors and provides insight into the improvement and/or development of these analogs as a therapeutic approach for the treatment of lung cancer.

Flow cytometric DNA analysis for determination of malignant potential in adrenal pheochromocytoma or paraganglioma: an Indian experience.

BACKGROUND: We analyzed the histological features and DNA flow cytometric results in 34 patients with pheochromocytoma and paragangliomas and attempted correlation with the biological behavior for determination of the malignant potential of these tumors. METHODS: DNA analysis was done on a FACSort flow cytometer using paraffin-embedded tissues. Histopathological analysis was performed using parameters, i.e., cell size (large, medium, and small), cell size variation, mitotic rate, nuclear pleomorphism, golden yellow to brown pigment in the tumor, necrosis, and venous invasion. RESULTS: Six tumors had high (>5/10HPF) mitotic rate while venous invasion was seen in three tumors. Fifty percent (18/34) of patients had aneuploid tumors, and 68% (23/34) of patients had high (>10%) S-phase fraction tumors. Aneuploidy correlated with >5/10HPF mitotic rate (P <.05) and diploidy with golden yellow to brown pigment (P <.01). The patients with aneuploid tumor had a worse prognosis than patients with diploid tumors (P =.004). No such difference was observed with low and high S-phase fractions (P =.748), presence and absence of venous invasion (P =.927), and mitotic rate (P =.159). Nuclear pleomorphism and necrosis were not significant factors in prognosis. CONCLUSIONS: Flow cytometric DNA analysis of paragangliomas and pheochromocytomas correlated with biological behavior in the patients with regard to metastasis and overall survival in the patients.