RCP induces FAK phosphorylation and ovarian cancer cell invasion with inhibition by curcumin.

Rab coupling protein (RCP) aggravates cancer cell metastasis and has been implicated in various cancer patient outcomes. Recently, we showed that RCP induces Slug expression and cancer cell invasion by stabilizing the ß1 integrin protein. In the present study, we demonstrated that FAK is implicated in RCP-induced EGFR phosphorylation and ovarian cancer cell invasion with inhibition by curcumin. Ectopic expression of RCP induced FAK phosphorylation, which links ß1 integrin with EGFR and participates in a positive regulation loop with EGFR. Interestingly, we observed for the first time that curcumin attenuates RCP-induced ovarian cancer cell invasion by blocking stabilization of ß1 integrin and consequently inhibiting FAK and EGFR activation, providing potential biomarkers for ovarian cancer and therapeutic approaches for this deadly disease.

Resveratrol suppresses breast cancer cell invasion by inactivating a RhoA/YAP signaling axis.

Hippo/YAP signaling is implicated in tumorigenesis and progression of various cancers. By inhibiting a plethora signaling cascades, resveratrol has strong anti-tumorigenic and anti-metastatic activity. In the present study, we demonstrate that resveratrol decreases the expression of YAP target genes. In addition, our data showed that resveratrol attenuates breast cancer cell invasion through the activation of Lats1 and consequent inactivation of YAP. Strikingly, we also demonstrate that resveratrol inactivates RhoA, leading to the activation of Lats1 and induction of YAP phosphorylation. Further, resveratrol in combination with other agents that inactivate RhoA or YAP showed more marked suppression of breast cancer cell invasion compared with single treatment. Collectively, these findings indicate the beneficial effects of resveratrol on breast cancer patients by suppressing the RhoA/Lats1/YAP signaling axis and subsequently inhibiting breast cancer cell invasion.

Bupivacaine decreases cell viability and matrix protein synthesis in an intervertebral disc organ model system.

BACKGROUND CONTEXT: Bupivacaine is a local anesthetic commonly used for back pain management in interventional procedures. Cytotoxic effects of bupivacaine have been reported in articular cartilage and, recently, in intervertebral disc cell culture. However, the relevance of these effects to discs in vivo remains unclear. This study examines the effect of bupivacaine on disc cell metabolism using an organotypic culture model system that mimics the in vivo environment. PURPOSE: To assess the effect of bupivacaine on disc cell viability and matrix protein synthesis using an organotypic model system and to determine whether this anesthetic has toxic effects. STUDY DESIGN: Mouse intervertebral discs were isolated and maintained ex vivo in an organotypic culture then exposed to clinically relevant concentrations of bupivacaine, and the impact on disc cell viability and matrix proteoglycan (PG) and collagen syntheses were measured in the presence and absence of the drug. SUBJECTS: Mouse functional spine units (FSUs) were isolated from the lumbar spines of 10-week-old mice. OUTCOME MEASURES: Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Total PG and collagen syntheses were determined by measuring the incorporation of radioactive (35)S-sulfate and (3)H-l-proline into PG and collagen, respectively. METHODS: Organotypic cultures of mouse FSUs were exposed to different concentrations (0%-0.5%) of bupivacaine for variable amounts of time (0-2 hours). Cell viability within disc tissue was quantified by MTT staining and histologic assay. Matrix protein synthesis was measured by incorporation of radioactive (35)S-sulfate (for PG synthesis) and (3)H-l-proline (for collagen synthesis). RESULTS: Untreated mouse disc organs were maintained in culture for up to 1 month with minimal changes in tissue histology, cell viability, and matrix protein synthesis. Exposure to bupivacaine decreased cell viability in a dose- and time-dependent manner. Exposure to bupivacaine at concentrations less than or equal to 0.25% did not significantly affect matrix protein synthesis. However, at 0.5% bupivacaine, collagen synthesis was reduced by fourfold and PG synthesis by threefold. CONCLUSIONS: Mouse discs can be successfully maintained ex vivo for upward of 4 weeks with little cell death, change in histologic structure, or matrix protein synthesis. This organotypic model system closely mimics the in vivo environment of the disc. Exposure of these cultures to bupivacaine dramatically decreased cell viability and matrix protein synthesis in a dose- and time-dependent manner. These findings corroborate those previously reported by Lee et al. using disc cell culture and demonstrate that this anesthetic at clinically relevant doses is toxic to intervertebral discs in both cell culture and disc organ models representative of the native architectural context.