Lidocaine Inhibits Rat Prostate Cancer Cell Invasiveness and Voltage-Gated Sodium Channel Expression in Plasma Membrane

There is increasing evidence, mostly from breast cancer, that use of local anaesthetics during surgery can inhibit disease recurrence by suppressing the motility of the cancer cells dependent on inherent voltage-gated sodium channels (VGSCs). Here, the possibility that lidocaine could affect cellular behaviours associated with metastasis was tested using the Dunning cell model of rat prostate cancer. Mostly, the strongly metastatic (VGSC-expressing) Mat-LyLu cells were used under both normoxic and hypoxic conditions. The weakly metastatic AT-2 cells served for comparison in some experiments. Lidocaine (1-500 μM) had no effect on cell viability or growth but suppressed Matrigel invasion dose dependently in both normoxia and hypoxia. Used as a control, tetrodotoxin produced similar effects. Exposure to hypoxia increased Nav1.7 mRNA expression but VGSCα protein level in plasma membrane was reduced. Lidocaine under both normoxia and hypoxia had no effect on Nav1.7 mRNA expression. VGSCα protein expression was suppressed by lidocaine under normoxia but no effect was seen in hypoxia. It is concluded that lidocaine can suppress prostate cancer invasiveness without effecting cellular growth or viability. Extended to the clinic, the results would suggest that use of lidocaine, and possibly other local anaesthetics, during surgery can suppress any tendency for post-operative progression of prostate cancer.

Drug repurposing: Metformin's effect against liver tissue damage in diabetes and prostate cancer model

Background

There are evidences linking diabetes to the pathogenesis and progression of various cancers. Metformin is a well-known antidiabetic drug that reduces the levels of circulating glucose and insulin in patients with both insulin resistance and hyperinsulinemia. Aim of the present study was to evaluate the effect of metformin on the liver of rats bearing prostate cancer, diabetes and prostate cancer + diabetes via histopathological and biochemical methods.

Methods

Male Copenhagen rats were divided into six groups. Control group, diabetic group, cancer group, diabetic + cancer group, diabetic + cancer + metformin group, cancer + metformin group. Diabetes was induced by injecting single dose of streptozotocin (65 mg/kg) to Copenhagen rats, cancer induced 2 × 104 Mat-LyLu cells. Metformin treatment was administered daily by gavage following inocculation of the Mat- Lylu cells to fifth and sixth group. The experiment was terminated on the 14th day following Mat-LyLu cell injection. At the end of the experimental period, the rats were sacrificed, and liver tissue was taken. Liver damage was scored. Biochemically, serum prostate-specific antigen level was determined by employing Enzyme Linked Immuno Sorbent Assay method. In addition, the activities of different enzyme and biochemical parameters were determined spectrophotometrically inform the hepatic tissue specimens.

Results

The findings of this study reveal that histopathological and biochemical damage in cancer and diabetic + cancer groups decreased significantly in the metformin treated groups.

Conclusion

These highlights that the antidiabetic drug metformin can be repositioned for attenuating liver tissue damage associated with prostate cancer and diabetes.