The combination therapy of HIF1α inhibitor LW6 and cisplatin plays an effective role on anti-tumor function in A549 cells

Hypoxia-inducible factor 1α (HIF1α) has been demonstrated to be involved in the resistance of various human cancer cells to chemotherapies. However, the correlation between HIF1α and the sensitivity of human non-small cell lung cancer (NSCLC) cells to cisplatin has not been illuminated. The aim of the present study was to investigate the effects of HIF1α on drug resistance in NSCLC cells. A549 cells were incubated in 21% or 0.5% O2 followed by the assessment of the level of HIF1α with qRT-PCR and western blot and ROS level by DCFH-DA assays. Effects of hypoxia or HIF1α inhibitor LW6 on the proliferation and apoptosis of A549 cells were evaluated via CCK-8 and flow cytometry assays. IC50 of A549 cells to cisplatin was determined by MTT assay. The mitochondrial membrane potential (MMP) was measured via JC-1 staining. Moreover, the expression of apoptosis related protein (Bcl-2, Bax) and drug resistance related proteins (MDR1, MRP1) were measured by western blotting. Exposure of A549 cells to 1% O2 significantly up-regulated HIF1α expression, maintained cell viability to cisplatin but decreased the ROS level, which promoted chemoresistance to cisplatin. LW6-treated A549 cells showed an increase in ROS level that blocked the hypoxia induced resistance to cisplatin and in addition, decreased expression of MDR1 and MRP1 in cisplatin-treated cells. This study revealed that hypoxia-improved cisplatin chemoresistance of NSCLC cells by regulated MDR1 and MRP1 expression via HIF1α/ROS pathway is reversed by LW6, suggesting that LW6 may act as effective sensitizer in chemotherapy for NSCLC.

Doctors' knowledge of post-splenectomy prophylaxis

A questionnaire was sent to 160 hospital doctors and 200 general practitioners about post-splenectomy prophylaxis during the month of September 1995. A total of 118 questionnaires were returned (43% hospital doctors and 25% GPs). Most doctors (99%) knew that splenectomised patients were at risk of pneumococcal infection; 72% of hospital doctors and 50% of GPs knew of the risk of Haemophilus influenza infection but only 50% of hospital doctors and 33% of GPs knew of the same risks involving meningococcal infection and malaria. Half of the GPs were not aware of H. influenzae type B (Hib) vaccine for prophylaxis and 85% of these and 50% of hospital doctors did not know prophylaxis should be lifelong. There was no significant difference in the knowledge between hospital doctors and GPs.