morphinans and Esophageal-Neoplasms

Radiation therapy is one of the most important treatments for unresectable and locally advanced esophageal squamous cell carcinoma (ESCC), however, the response to radiotherapy is sometimes limited by the development of radioresistance. Sinomenine hydrochloride (SH) has anticancer activity, but its effect on the radiosensitivity of ESCC is unclear. We determined the effect of SH on the radiosensitivity of ESCC cells and elucidated its potential radiosensitization mechanisms in vitro and in vivo. ESCC cells were subjected to SH and radiation, both separately and in combination. Untreated cells served as controls. The CCK‑8 assay was used to evaluate cell proliferation, and the clonogenic assay to estimate radiosensitization. Flow cytometry was used to investigate cell cycle phases and cell apoptosis. Bcl‑2, Bax, cyclin B1, CDK1, Ku86, Ku70, and Rad51 expression was evaluated using western blotting. In vivo, tumor xenografts were created using BALB/c nude mice. Tumor‑growth inhibition was recorded, and Ki‑67 and Bax expression in the tumor tissues was assessed using immunohistochemistry. SH inhibited ESCC cell growth and markedly increased their radiosensitivity by inducing G2/M phase arrest. SH combined with radiation therapy significantly increased ESCC cell apoptosis. The molecular mechanism by which SH enhanced radiosensitivity of ESCC cells was related to Bcl‑2, cyclin B1, CDK1, Ku86, Ku70, and Rad51 downregulation and Bax protein expression upregulation. SH combined with radiation considerably delayed the growth of tumor xenografts in vivo. Immunohistochemical analysis showed that in the SH combined with radiation group, the expression of Bax was significantly higher while that of Ki‑67 was lower than the expressions in the control groups. Taken together, our findings showed that SH could improve the sensitivity of radiation in ESCC cells by inducing G2/M phase arrest, promoting radiation‑induced apoptosis and inhibiting DSB‑repair pathways. SH appears to be a prospective radiosensitizer for improving the efficacy of radiotherapy for ESCC.

Topics: Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Mice; Morphinans; Neoplasm Proteins; Radiation Tolerance; Xenograft Model Antitumor Assays

To investigate the inhibitory effects of sinomenine (SIN) combined with 5-fluorouracil (5-FU) on esophageal carcinoma in vitro and in vivo.. Esophageal carcinoma (Eca-109) cells were cultured in DMEM. The single or combined growth inhibition effects of SIN and 5-FU on the Eca-109 cells were examined by measuring the absorbance of CCK-8 dye in living cells. Hoechst 33258 staining and an Annexin V/PI apoptosis kit were used to detect the percentage of cells undergoing apoptosis. Western blotting was used to investigate the essential mechanism underlying SIN and 5-FU-induced apoptosis. SIN at 25 mg/kg and 5-FU at 12 mg/kg every 3 d, either combined or alone, was injected into nude mice and tumor growth inhibition and side effects of the drug treatment were observed.. SIN and 5-FU, both in combination and individually, significantly inhibited the proliferation of Eca-109 cells and induced obvious apoptosis. Furthermore, the combined effects were greater than those of the individual agents (P < 0.05). Annexin V/PI staining and Hoechst 33258 staining both indicated that the percentage of apoptotic cells induced by SIN and 5-FU combined or alone were significantly different from the control (P < 0.05). The up-regulation of Bax and down-regulation of Bcl-2 showed that the essential mechanism of apoptosis induced by SIN and 5-FU occurs via the mitochondrial pathway. SIN and 5-FU alone significantly inhibited the growth of tumor xenografts in vivo, and the combined inhibition rate was even higher (P < 0.05). During the course of chemotherapy, no obvious side effects were observed in the liver or kidneys.. The combined effects of SIN and 5-FU on esophageal carcinoma were superior to those of the individual compounds, and the drug combination did not increase the side effects of chemotherapy.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Synergism; Esophageal Neoplasms; Fluorouracil; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Morphinans; Proto-Oncogene Proteins c-bcl-2; Tumor Burden; Xenograft Model Antitumor Assays