Zoledronic acid exhibits radio-sensitizing activity in human pancreatic cancer cells via inactivation of STAT3/NF-κB signaling

Molecular mechanisms of resveratrol as chemo and radiosensitizer in cancer

One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment.

Combining radiation therapy with zoledronate for the treatment of osteo-invasive feline oral squamous cell carcinoma

Feline oral squamous cell carcinoma (FOSCC) is the most common oral tumour diagnosed in pet cats and carries a poor prognosis with <10% one-year survival despite multi-modal therapies. Tumours of the mandible or maxilla are frequently osteo-invasive and pain can result from osteolysis. Zoledronate is a bisphosphonate that inhibits osteoclasts and reduces bone resorption. Radiation therapy (RT) is used to treat FOSCC due to anti-cancer activity and ability to improve quality of life. We hypothesized RT can be safely combined with zoledronate, and that this combinatory therapy would be efficacious, well tolerated, and result in decreased bone resorption in cats with FOSCC. SCCF1 cell line was treated with zoledronate before, concurrently, or after RT, and clonogenic assays were performed to determine if an optimal dosing schedule would be identified. Nine cats with osteoinvasive FOSCC were recruited for treatment with 4 weekly doses of 8 Gy RT combined with zoledronate administered at the first and fourth treatments. Serial CT scans were performed to assess tumour response. Safety and tolerability were monitored with hematologic and biochemical parameters, and acute radiation effects were characterized. Serum c-telopeptide (CTx) and relative bone mineral density (rBMD) by dual -energy X-ray absorptiometry (DEXA) quantified bone resorption. In vitro studies showed no clear benefit to timing of zoledronate with RT, therefore all zoledronate was administered concurrently with RT in FOSCC patients. Based on tumour volume, 4/9 (44.4%) cats achieved partial remission, 4/9 (44.4%) stable disease and 1/9 (11.1%) had progressive disease. The combinatory therapy was well-tolerated based on biochemical measurements, and all patients experienced decreased serum CTx. Combining RT with zoledronate in tumour-bearing cats is safe, well-tolerated, results in a partial remission rate of up to 44%, and decreases serum CTx, a marker of bone resorption.

Dysregulation of ECRG4 is associated with malignant properties and of prognostic importance in human gastric cancer

BACKGROUND

We have previously characterized esophageal carcinoma-related gene 4 (ECRG4) as a novel tumor suppressor gene, which is frequently inactivated in nasopharyngeal carcinoma and breast cancer. Nevertheless, the expression status and prognostic significance of ECRG4 maintain elusive in human gastric cancer. Herein, we examined ECRG4 expression profile in gastric cancer and assessed its association with clinicopathological characteristics and patient survival.

METHODS

Online data mining, real-time RT-PCR and immunohistochemistry were employed to determined ECRG4 expression at transcriptional and protein levels in tumors vs. noncancerous tissues. Statistical analyses including the Kaplan-Meier survival analysis and the Cox hazard model were utilized to detect the impact on clinical outcome. Moreover, ECRG4 expression was silenced in gastric cancer SGC7901 cells, and cell proliferation, colony formation and invasion assays were carried out.

RESULTS

ECRG4 mRNA and protein levels were obviously downregulated in cancer tissues than noncancerous tissues. Statistical analyses demonstrated that low ECRG4 expression was found in 34.5% (58/168) of primary gastric cancer tissues, which was associated with higher histological grade (P= 0.018), lymph node metastasis (P= 0.011), invasive depth (P= 0.020), advanced tumor stage (P= 0.002) and poor overall survival (P< 0.001). Multivariate analysis showed ECRG4 expression is an independent prognostic predictor (P< 0.001). Silencing ECRG4 expression promoted gastric cancer cell growth and invasion. Western blot analysis revealed the anti-metastatic functions of ECRG4 by downregulating of E-cadherin and α-Catenin, as well as upregulating N-cadherin and Vimentin.

CONCLUSIONS

Our observations reveal that ECRG4 expression is involved in gastric cancer pathogenesis and progression, and may serve as a candidate prognostic biomarker for this disease.

STAT3 Contributes to Radioresistance in Cancer

Radiotherapy has been used in the clinic for more than one century and it is recognized as one of the main methods in the treatment of malignant tumors. Signal Transducers and Activators of Transcription 3 (STAT3) is reported to be upregulated in many tumor types, and it is believed to be involved in the tumorigenesis, development and malignant behaviors of tumors. Previous studies also found that STAT3 contributes to chemo-resistance of various tumor types. Recently, many studies reported that STAT3 is involved in the response of tumor cells to radiotherapy. But until now, the role of the STAT3 in radioresistance has not been systematically demonstrated. In this study, we will review the radioresistance induced by STAT3 and relative solutions will be discussed.

Carbon-Ion Beam Irradiation Alone or in Combination with Zoledronic acid Effectively Kills Osteosarcoma Cells

Osteosarcoma (OSA) is the most common malignant bone tumor in children and adolescents. The overall five-year survival rate for all bone cancers is below 70%; however, when the cancer has spread beyond the bone, it is about 15–30%. Herein, we evaluated the effects of carbon-ion beam irradiation alone or in combination with zoledronic acid (ZOL) on OSA cells. Carbon-ion beam irradiation in combination with ZOL significantly inhibited OSA cell proliferation by arresting cell cycle progression and initiating KHOS and U2OS cell apoptosis, compared to treatments with carbon-ion beam irradiation, X-ray irradiation, and ZOL alone. Moreover, we observed that this combination greatly inhibited OSA cell motility and invasion, accompanied by the suppression of the Pi3K/Akt and MAPK signaling pathways, which are related to cell proliferation and survival, compared to individual treatments with carbon-ion beam or X-ray irradiation, or ZOL. Furthermore, ZOL treatment upregulated microRNA (miR)-29b expression; the combination with a miR-29b mimic further decreased OSA cell viability via activation of the caspase 3 pathway. Thus, ZOL-mediated enhancement of carbon-ion beam radiosensitivity may occur via miR-29b upregulation; co-treatment with the miR-29b mimic further decreased OSA cell survival. These findings suggest that the carbon-ion beam irradiation in combination with ZOL has high potential to increase OSA cell death.