Metformin activates AMPK and mTOR to Inhibit RANKL-stimulated osteoclast formation.

OBJECTIVE: Metformin is a medication used to treat type 2 diabetes by inhibiting hepatic glucose production through adenosine monophosphate-activated protein kinase (AMPK) activation. Autophagy is closely related to the homeostasis and stress mechanisms of the body. In recent years, much research has arisen on therapeutic methods utilizing autophagy mechanisms to treat diagnoses such as metabolic diseases, tumors, and Alzheimer's disease. This study thus aimed to investigate the effects of metformin treatment on the differentiation of osteoclasts and changes in AMPK mechanisms, which play an important role in regulating energy homeostasis, and mTOR, a highly conserved kinase that regulates autophagy. MATERIALS AND METHODS: Experimentation, including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, tartrate-resistant acid phosphate (TRAP) staining, pit formation assay, immunofluorescence, western blotting, and real-time polymerase chain reaction (PCR) was performed to investigate the effects of metformin on osteoclast differentiation. Additionally, to investigate its association with AMPK and pathways, the AMPK inhibitor compound C and mammalian targets of rapamycin (mTOR) activator leucine were used to examine the expression of osteoclast- or autophagy-related proteins, genes, and TRAP-positive cells. RESULTS: Metformin showed no cytotoxic effects on mouse osteoblastic cell lines (MC3T3-E1) and murine macrophage cell lines (RAW264.7) but did inhibit osteoclast differentiation. Furthermore, metformin was found to inhibit osteoclast differentiation through AMPK activation and mTOR inhibition. In turn, AMPK inhibition using compound C promoted osteoclast differentiation, and mTOR activation using leucine inhibited autophagy and osteoclast differentiation. CONCLUSIONS: Metformin activates the AMPK pathway while functioning as an activator of mTOR, thereby leading to the inhibition of autophagy and osteoclast differentiation.

Development and validation of Chemotherapy-induced Alopecia Distress Scale (CADS) for breast cancer patients.

BACKGROUND: A psychometric scale for assessing the distress that breast cancer patients experience due to the chemotherapy-induced alopecia was developed and validated. PATIENTS AND METHODS: Twenty-five items for chemotherapy-induced alopecia distress were developed based on a qualitative study, and a cross-sectional survey was conducted with 305 Korean women with breast cancer. To extract factor structure and evaluate construct validity, exploratory and confirmatory factor analysis (CFA) was carried out. Concurrent and discriminant validity were tested by correlations with the psychosocial factors. In addition, external validity analysis was conducted using data from another prospective study of 428 breast cancer patients. RESULTS: Exploratory factor analysis and CFA yielded 17 items in four domains and the model fit was good (CFI=0.925). Coefficient alphas ranged from 0.77 to 0.95 for subdomains and 0.95 for total, and it was similar with the validation dataset confirming its external validity. The total Chemotherapy-Induced Alopecia Distress Scale (CADS) was moderately correlated with the body image (r=-0.47, P<0.001), more weakly correlated with the patients' overall quality of life (QOL, r=-0.28, P<0.001), but did not correlate with self-esteem (r=-0.07, P=0.23). CONCLUSIONS: Our study confirmed that the CADS is a reliable and valid tool for measuring distress of chemotherapy-induced alopecia.

Prospective analysis of quality of life in elderly patients treated with adjuvant chemotherapy for non-small-cell lung cancer.

BACKGROUND: Given the more comorbidities with a decline in physiologic reserve, it can be challenging to make appropriate treatment decisions in the elderly. PATIENTS AND METHODS: Here, we prospectively evaluated and compared the health-related quality of life (HRQOL) of patients aged ≥ 65 with aged <65 who were treated with a postoperative chemotherapy for completely resected stage Ib, II or IIIa non-small-cell lung cancer (NSCLC). Either four cycles of paclitaxel (Taxol)-carboplatin (PC) or vinorelbine-cisplatin (NP) was used. The HRQOL was assessed with EORTC QLQ-C30 and EORTC QLQ-LC13. RESULTS: Between October 2008 and October 2011, a total of 139 patients (aged <65, n = 73; ≥ 65, n = 66) were enrolled, and 127 (91.4%) completed the questionnaire. Overall, the quality of life (QOL) in elderly patients did not significantly deteriorate with adjuvant chemotherapy and the time trend of QOL in elderly patients was similar to that of younger patients. Although the elderly suffered from increased treatment-related adverse events involving sore mouth, peripheral neuropathy and alopecia compared with the baseline, the same time trends were also observed in younger group. The mean dose intensities (MDIs) for PC and NP regimen were not significantly different between the two age groups. CONCLUSIONS: Postoperative chemotherapy did not substantially reduce HRQOL in elderly NSCLC patients, and HRQOL during and after adjuvant chemotherapy did not significantly differ by age.