furthermore, this was observed in all NSCLC cell lines examined. Bfl 1overex pression has been reported to underlie resistance to var ious apoptotic stimuli, and we previously observed that Bfl 1 is frequently over expressed in lung cancer cell lines. Therefore, we speculated that Bfl 1 might regulate the sensitivity selleck Ganetespib of NSCLC to gemcitabine. As was expected, direct Bfl 1 suppression using siRNA sen sitized cells to gemcitabine induced apoptosis in A549 cells. In a study conducted by Brien et al. in B lympho blastoid and diffuse large B cell lymphoma cell lines, Bfl 1 silencing was found to potently induce apoptosis, and sensitize cells to rituximab mediated cell death and apoptosis by doxorubicin, vincristine, cisplatin, or flu darabine.

In the present study using lung cancer cell lines, Inhibitors,Modulators,Libraries although siRNA mediated Bfl 1 suppression per se did not affect cell viability, it sensitized cells to gemcitabine. Therefore, the present and our previous findings suggest that Bfl 1 is a feasible molecular target for enhancing Inhibitors,Modulators,Libraries the efficacy of gemcitabine in lung cancer. Furthermore, in view of the fact that BC itself alone has a cytotoxic effect, it would appear that BC is likely to be better than siRNA at chemosensitizing cells. Although previous studies have reported that NF B regulates the expression of Bcl xL and/or Bcl 2 in various cell types, we observe little changes in the level of Bcl xL and Bcl 2 in cells treated with gemcitabine at low concentra tions inducing NF B activation either by RT Inhibitors,Modulators,Libraries PCR and real time RT PCR.

It is possible that Bfl 1, a direct tar get of NF B, might function as Inhibitors,Modulators,Libraries an Inhibitors,Modulators,Libraries important and sen sitive anti apoptotic Bcl 2 family protein reflecting the alteration of NF B activity in NSCLC cells, particularly in terms of response to gemcitabine. Although Bfl 1 is an anti apoptotic bcl 2 family mem ber and primarily prevents apoptosis, its protective effect depends on cell type and apoptotic stimulus. Furthermore, Bfl 1 can be converted into a pro apopto tic molecule when processed by proteasome or TNF receptor signaling in pro B cells. In this system, the Bfl 1 C terminal domain was important for the pro apoptotic function of Bfl 1, because it was required for Bfl 1 ubiquitination and its localization at the mitochon drial membrane.

Our group, previously, demon strated that anti apoptotic Bfl 1 is converted to a pro apoptotic selleck chem protein when fused with GFP, and that the 29 amino acids of its C terminal region are sufficient to induce apoptotic cell death via the mitochondrial path way and caspase activation in 293T cells. An amphipathic tail anchoring domain of the Bfl 1 C term inal region has been implicated in the targeting of Bfl 1 to the mitochondrial membrane to induce apoptosis. These findings led us to hypothesize that the Bfl 1 C terminal region fused with GFP could be harnessed as a gene therapy in combination with che motherapeutic agents to achieve management of cancer.