STAT3 inhibitor stattic enhances radiosensitivity in esophageal squamous cell carcinoma.

The radioresistance of esophageal squamous cell carcinoma (ESCC) remains an obstacle for the effective radiotherapy of ESCC. This study aimed to investigate the radiosensitization of ESCC by signal transducer and activator of transcription 3 (STAT3) inhibitor stattic. ECA109, TE13, and KYSE150 cell lines were exposed to hypoxia and treated with stattic or radiation, alone or in combination. Cell proliferation, colony formation, apoptosis, and double-stranded DNA breaks (DSBs) were examined. In addition, ECA109 cells were xenografted into nude mice and treated with radiation and/or stattic. The levels of STAT3, p-STAT3, hypoxia-inducible factor 1α (HIF-1α), and vascular endothelial growth factor (VEGF) in ESCC cells and xenografts were detected by Western blot and immunohistochemical analysis. Our results showed that stattic efficiently radiosensitized ESCC cells and xenografts, especially under hypoxia. Moreover, stattic inhibited STAT3 activation and downregulated HIF-1α and VEGF expression. In conclusion, stattic confers radiosensitivity in ESCC cells in vitro and in vivo and is a potential adjuvant for the radiotherapy of ESCC in the clinical setting.

Targets and molecular mechanisms of triptolide in cancer therapy.

Triptolide (TPL/TL) is a natural drug with novel anticancer effects. Preclinical studies indicated that TPL inhibits cell proliferation, induces cell apoptosis, inhibits tumor metastasis and enhances the effect of other therapeutic methods in various cancer cell lines. Multiple molecules and signaling pathways, such as caspases, heat-shock proteins, NF-κB, and deoxyribonucleic acid (DNA) repair-associated factors, are associated with the anti-cancer effect. TPL also improves chemoradiosensitivity in cancer therapy. Phase I trials indicate the potential clinical value of TPL use. However, further trials with larger sample sizes are needed to confirm these results.

Berberine inhibits the expression of hypoxia induction factor-1alpha and increases the radiosensitivity of prostate cancer.

BACKGROUND: The radiation resistance of prostate cancer remains the primary obstacle to improve patient survival. This study aimed to investigate the effects of berberine, a commonly used natural product, on the radiosensitivity of prostate cancer. METHODS: Prostate cancer cell line LNCaP and DU-145 were subjected to hypoxia and/or ionizing radiation (IR), in the presence or absence of berberine treatment. Cell growth and colony formation, and apoptosis were evaluated. Moreover, LNCaP cells were xenografted into nude mice and subjected to IR and/or berberine treatment. The expression of HIF-1α and VEGF in prostate cancer cells and xenografts was detected by Western blot analysis. RESULTS: Berberine increased radiosensitivity of prostate cancer cells and xenografts in a dose dependent manner, and this was correlated with the inhibition of HIF-1α and VEGF expression. CONCLUSIONS: Berberine may inhibit the expression of HIF-1α and VEGF and thus confer radiosensitivity on prostatic cancer cells. Berberine has potential application as an adjuvant in radiotherapy of prostatic cancer. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1519827543125021.