The Effect of Lidocaine and Bosutinib on 4T1 Murine Breast Cancer Cell Behaviour In Vitro.

BACKGROUND/AIM: Systemic lidocaine has recently emerged as a promising agent possessing numerous potentially anti-neoplastic effects. In vitro studies suggest that lidocaine may prevent metastasis by acting on the tyrosine kinase enzyme Src. Intravenous lidocaine has been reported to reduce pulmonary metastasis in vivo in a murine breast cancer model, however the beneficial effect is abolished by the Src inhibitor bosutinib. In this study we examined whether lidocaine and/or bosutinib affects 4T1 breast cancer cell activity in vitro and whether any drug interactions similar to that seen in murine models occur. MATERIALS AND METHODS: 4T1 murine breast cancer cells were exposed to lidocaine and/or bosutinib. Cell viability after 1 h of exposure was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell migration after 24 h of exposure was measured using the Oris™ migration assay. RESULTS: Lidocaine and bosutinib alone or combined inhibited 4T1 cell viability and migration, but only at supratherapeutic concentrations. Bosutinib did not modulate lidocaine's effect on viability or migration at any concentration tested. CONCLUSION: Although lidocaine may inhibit 4T1 metastasis in vivo, a direct effect on 4T1 cells is not detectable in vitro at non-toxic concentrations and unlike murine model testing, no unusual interaction with bosutinib was detected. Lidocaine's anti-metastatic properties are likely to be complex and multifactorial and difficult to replicate outside of a biological host.

Effects of Lidocaine and Src Inhibition on Metastasis in a Murine Model of Breast Cancer Surgery.

Breast cancer recurs in 20% of patients following intended curative resection. In vitro data indicates that amide local anaesthetics, including lidocaine, inhibit cancer cell metastasis by inhibiting the tyrosine kinase enzyme Src. In a murine breast cancer surgery model, systemic lidocaine reduces postoperative pulmonary metastases. We investigated whether the additional administration of bosutinib (a known Src inhibitor) influences lidocaine's observed beneficial effect in this in vivo model. Female BALB/c mice (n = 95) were inoculated with 25,000 4T1 cells into the mammary fad pad and after 7 days the resulting tumours were excised under sevoflurane anaesthesia. Experimental animals were randomized to one of four treatments administered intravenously prior to excision: lidocaine, bosutinib, both lidocaine and bosutinib in combination, or saline. Animals were euthanized 14 days post-surgery and lung and liver metastatic colonies were evaluated. Post-mortem serum was analysed for MMP-2 and MMP-9, pro-metastatic enzymes whose expression is influenced by the Src pathway. Lidocaine reduced lung, but not liver metastatic colonies versus sevoflurane alone (p = 0.041), but bosutinib alone had no metastasis-inhibiting effect. When combined with lidocaine, bosutinib reversed the anti-metastatic effect observed with lidocaine on sevoflurane anaesthesia. Only lidocaine alone reduced MMP-2 versus sevoflurane (p = 0.044). Both bosutinib (p = 0.001) and bosutinib/lidocaine combined (p = 0.001) reduced MMP-9 versus sevoflurane, whereas lidocaine alone did not. In a murine surgical breast cancer model, the anti-metastatic effects of lidocaine under sevoflurane anaesthesia are abolished by the Src inhibitor bosutinib, and lidocaine reduces serum MMP-2. These results suggest that lidocaine may act, at least partly, via an inhibitory effect on MMP-2 expression to reduce pulmonary metastasis, but whether this is due to an effect on Src or via another pathway remains unclear.

Effect of Perioperative Lidocaine, Propofol and Steroids on Pulmonary Metastasis in a Murine Model of Breast Cancer Surgery.

Addressing the hypothesis that anaesthetic-analgesic technique during cancer surgery might influence recurrence or metastatic spread is a research priority. Propofol, which has anti-inflammatory properties in vitro, is clinically associated with reduced risk of cancer recurrence compared with sevoflurane anaesthesia in retrospective studies. Amide local anaesthetics, such as lidocaine, have cancer inhibiting effects in vitro. Steroids have anti-inflammatory and immunosuppressive effects and are associated with improved recovery after major non-cancer surgery. We compared the effects of propofol, lidocaine and methylprednisolone on postoperative metastasis in a murine model of breast cancer surgery under sevoflurane anaesthesia. 4T1 tumour cells were introduced into the mammary fat-pad of female BALB/c mice and the resulting tumour resected seven days later under general anaesthesia with sevoflurane. Mice (n = 72) were randomized to four treatment groups: Sevoflurane alone (control); Propofol group received 5 mg.kg-1; Lidocaine group received 1.5 mg.kg-1 followed by 2 mg.kg-1.h-1 infusion; Methylprednisolone group received 30 mg.kg-1 methylprednisolone. The primary outcome measure was pulmonary metastasis colony count, as assessed by in-vitro proliferation, two weeks post-operatively. This was achieved by treating the post-mortem lung tissue with collagenase IV, straining and culturing for 14 days prior to colony count. Compared with control, lidocaine and propofol each individually reduced pulmonary metastasis colonies; mean (SD) 846 (±581) vs. 88 (±52) vs. 34 (±44) respectively, (p = 0.0001 and p = 0.0001). Methylprednisolone increased lung metastasis, 2555 (±609) vs. 846 (±581), p = 0.0001. Post-operative hepatic metastatic disease and serum interleukin-6 and vascular endothelial growth factor levels were similar in all groups. In conclusion, in a murine model of breast cancer surgery during sevoflurane anaesthesia, propofol and lidocaine each decreased pulmonary metastasis, while methylprednisolone increased it.

Effect of Perioperative Lidocaine and Cisplatin on Metastasis in a Murine Model of Breast Cancer Surgery.

BACKGROUND/AIM: Mortality from breast cancer is usually attributable to metastasis. In vitro data suggest that amide local anaesthetics, e.g. lidocaine, inhibit metastasis by multiple mechanisms and recent in vivo data support this. Experimental data also suggest that opioids may inhibit cisplatin chemotherapy. Whether lidocaine would influence cisplatin chemotherapy has not been evaluated. MATERIALS AND METHODS: 4T1 cells were injected into the mammary gland of immunocompetent female BALB/c mice, with resection of the tumour under sevoflurane anaesthesia one week later. Mice (n=45) were randomized into one of three groups: The cisplatin group received 3 mg.kg-1 cisplatin; cisplatin and lidocaine group received 3 mg.kg-1 cisplatin and lidocaine bolus of 1.5 mg.kg-1 followed by an infusion of 2 mg.kg-1.h-1 The control group received sevoflurane only. All agents were given perioperatively. After 14 postoperative days, post-mortem lung, serum and liver samples were collected. Primary outcome measure was lung metastasis colony count. RESULTS: During sevoflurane anaesthesia, the addition of lidocaine to cisplatin significantly decreased metastatic lung colony count [(mean±SD) (157±87)] compared to control [846±581, (p=0.001)], and cisplatin alone [580±383, (p=0.018)]. However, liver metastasis colony count was not reduced with the combination of cisplatin and lidocaine (9.3±13.9) when compared to control (74.7±257.3), p=0.78 or to cisplatin alone (110±388.8), p=0.569. Serum VEGF and interleukin-6 concentrations were not significantly different. CONCLUSION: In a 4T1 murine model of breast cancer surgery, under sevoflurane anaesthesia, lidocaine enhanced the metastasis-inhibiting action of cisplatin. Clinical evaluation of the hypothesis that co-administration of systemic lidocaine during cisplatin chemotherapy seems warranted.

Exposure to 60% oxygen promotes migration and upregulates angiogenesis factor secretion in breast cancer cells.

Peri-operative factors, including anaesthetic drugs and techniques, may affect cancer cell biology and clinical recurrence. In breast cancer cells, we demonstrated that sevoflurane promotes migration and angiogenesis in high fractional oxygen but not in air. Follow-up analysis of the peri-operative oxygen fraction trial found an association between high inspired oxygen during cancer surgery and reduced tumor-free survival. Here we evaluated effects of acute, high oxygen exposure on breast cancer cell viability, migration and secretion of angiogenesis factors in vitro. MDA-MB-231 and MCF-7 breast cancer cells were exposed to 21%, 30%, 60%, or 80% v/v O2 for 3 hours. Cell viability at 24 hours was determined by MTT and migration at 24 hours with the Oris™ Cell Migration Assay. Secretion of angiogenesis factors at 24 hours was measured via membrane-based immunoarray. Exposure to 30%, 60% or 80% oxygen did not affect cell viability. Migration of MDA-MB-231 and MCF-7 cells was increased by 60% oxygen (P = 0.012 and P = 0.007, respectively) while 30% oxygen increased migration in MCF-7 cells (P = 0.011). These effects were reversed by dimethyloxaloylglycine. In MDA-MB-231 cells high fractional oxygen increased secretion of angiogenesis factors monocyte chemotactic protein 1, regulated on activation normal T-cell expressed and vascular endothelial growth factor. In MCF-7 cells, interleukin-8, angiogenin and vascular endothelial growth factor secretion was significantly increased by high fractional oxygen. High oxygen exposure stimulates migration and secretion of angiogenesis factors in breast cancer cells in vitro.