curcumin and Leiomyosarcoma

Uterine leiomyosarcomas generally do not respond well to standard chemotherapy. We previously demonstrated that curcumin, the active ingredient derived from the herb Curcuma longa, inhibits uterine leiomyosarcoma cells in vitro via the inhibition of the AKT-mammalian target of rapamycin (mTOR) pathway. As a preclinical investigation, we performed an in vivo study using female nude mice to confirm the therapeutic potential of curcumin against uterine leiomyosarcoma.. Human leiomyosarcoma cells, SK-UT-1, were inoculated in female nude mice to establish subcutaneous tumors. Either vehicle control or 250 mg/kg curcumin was administered intraperitoneally every day for 14 consecutive days, and the mice were then killed. The tumors were measured every 2-3 days. The tumors were processed for immunohistochemical analyses to detect total AKT, phosphorylated AKT, total mTOR, phosphorylated mTOR, and phosphorylated S6. To detect apoptosis, the tumors were stained for cleaved PARP and TUNEL. Ki-67 immunohistochemistry was performed to determine cell viability of the tumors.. Compared with the control, curcumin reduced uterine leiomyosarcoma tumor volume and mass significantly with a concordant decrease in mTOR and S6 phosphorylation. However, AKT phosphorylation was not significantly altered. Cleaved PARP and TUNEL staining increased significantly with curcumin administration, indicating the induction of apoptosis. There was no difference in Ki-67 staining between the two groups.. Curcumin inhibited uterine leiomyosarcoma tumor growth in vivo by targeting the AKT-mTOR pathway for inhibition.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Curcumin; Female; Humans; Ki-67 Antigen; Leiomyosarcoma; Mice; Mice, Inbred BALB C; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases; Uterine Neoplasms; Xenograft Model Antitumor Assays

Uterine leiomyosarcoma (LMS) has an unfavorable response to standard chemotherapy. A natural occurring compound, curcumin, has been shown to have inhibitory effects on cancers. We previously demonstrated that curcumin reduced uterine LMS cell proliferation by targeting the AKT-mTOR pathway and activating apoptosis. To further explore the anticancer effect of curcumin, we investigated the efficacy of curcumin on autophagy in LMS cells.. Cell proliferation in human uterine LMS cell lines, SKN and SK-UT-1, was assessed after exposure to rapamycin or curcumin. Autophagy was detected by Western blotting for light chain 3 and sequestosome 1 (SQSTM1/p62) expression. Apoptosis was confirmed by Western blotting for cleaved poly (ADP-ribose) polymerase (PARP).. Both rapamycin and curcumin potently inhibited SKN and SK-UT-1 cell proliferation in a dose-dependent manner. Curcumin induced autophagy and apoptosis in SKN and SK-UT-1 cells, whereas rapamycin, a specific mTOR inhibitor, did not. Curcumin increased extracellular signal-regulated kinase 1/2 activity in both SKN and SK-UT-1 cells, whereas PD98059, an MEK1 inhibitor, inhibited both the extracellular signal-regulated kinase 1/2 pathway and curcumin-induced autophagy.. These experimental findings suggest that curcumin is a potent inhibitor of cell proliferation in uterine LMS and provide new insights about ongoing signaling events leading to the possible development of a new therapeutic agent.

Topics: Antineoplastic Agents; Apoptosis; Autophagy; Blotting, Western; Cell Proliferation; Curcumin; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Leiomyosarcoma; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Cells, Cultured; Uterine Neoplasms

Uterine leiomyosarcoma (LMS) has an unfavorable response to standard chemotherapeutic regimens. Two natural occurring compounds, curcumin and epigallocatechin gallate (EGCG), are reported to have anti-cancer activity. We previously reported that curcumin reduced uterine LMS cell proliferation by targeting the AKT-mTOR pathway. However, challenges remain in overcoming curcumin's low bioavailability.. The human LMS cell line SKN was used. The effect of EGCG, curcumin or their combination on cell growth was detected by MTS assay. Their effect on AKT, mTOR, and S6 was detected by Western blotting. The induction of apoptosis was determined by Western blotting using cleaved-PARP specific antibody, caspase-3 activity and TUNEL assay. Intracellular curcumin level was determined by a spectrophotometric method. Antibody against EGCG cell surface receptor, 67-kDa laminin receptor (67LR), was used to investigate the role of the receptor in curcumin's increased potency by EGCG.. In this study, we showed that the combination of EGCG and curcumin significantly reduced SKN cell proliferation more than either drug alone. The combination inhibited AKT, mTOR, and S6 phosphorylation, and induced apoptosis at a much lower curcumin concentration than previously reported. EGCG enhanced the incorporation of curcumin. 67LR antibody partially rescued cell proliferation suppression by the combination treatment, but was not involved in the EGCG-enhanced intracellular incorporation of curcumin.. EGCG significantly lowered the concentration of curcumin required to inhibit the AKT-mTOR pathway, reduce cell proliferation and induce apoptosis in uterine LMS cells by enhancing intracellular incorporation of curcumin, but the process was independent of 67LR.

Topics: Apoptosis; Biological Availability; Catechin; Cell Line, Tumor; Cell Proliferation; Curcumin; Drug Synergism; Female; Humans; Leiomyosarcoma; Oncogene Protein v-akt; Receptors, Laminin; Ribosomal Protein S6 Kinases; Signal Transduction; TOR Serine-Threonine Kinases; Uterine Neoplasms

Uterine leiomyosarcoma generally has an unfavorable response to standard chemotherapy. The loss of PTEN which results in constitutive AKT-mTOR activation causes an increase in leiomyosarcoma formation in mice. The active ingredient derived from the herb Curcuma longa, curcumin, shows antitumor properties in a variety of cancer cell lines by altering a number of oncogenic pathways. To explore the possibility of curcumin as an alternative to standard chemotherapy, we decided to investigate curcumin's antitumor effect on uterine leiomyosarcoma cells.. Human leiomyosarcoma cell lines, SKN and SK-UT-1, were cultured for in vitro experiments. Rapamycin or curcumin was added in different doses and their effect on cell growth was detected by MTS assay. The influence of rapamycin or curcumin on AKT, mTOR, p70S6 and S6 phosphorylation and protein expression was detected by Western Blotting. The ability of rapamycin or curcumin to induce apoptosis was determined by Western blotting using cleaved-PARP specific antibody, Caspase-3 activity assay and TUNEL assay.. Both rapamycin and curcumin significantly reduced SKN cell proliferation. Curcumin inhibited mTOR, p70S6 and S6 phosphorylation similar with rapamycin. Cleaved PARP, caspase-3 activity and DNA fragmentation increased proportional with curcumin concentration. At a high concentration, curcumin significantly induced apoptosis in SKN cells, but not rapamycin.. Curcumin inhibited uterine leiomyosarcoma cells' growth by targeting the AKT-mTOR pathway for inhibition. However, rapamycin, a specific mTOR inhibitor, did not induce apoptosis in SKN cells unlike curcumin that also has a pro-apoptotic potential in SKN cells.

Topics: AMP-Activated Protein Kinases; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Curcumin; Dose-Response Relationship, Drug; Enzyme Activation; Female; Humans; Leiomyosarcoma; Oncogene Protein v-akt; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Uterine Neoplasms