Pregnane X receptor (PXR) is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. PXR is a key xenobiotic receptor that regulates the expression of genes implicated in drug metabolism, detoxification and clearance, including drug metabolizing enzymes and transporters, suggesting that it is significant in the drug resistance of cancer cells. PXR is expressed in a wide range of tissues in the human body. Studies have demonstrated that PXR is expressed in a variety of tumor types, correlating not only with drug resistance but also with the cell proliferation, apoptosis and prognosis of cancer. The purpose of the present review is to provide a comprehensive review of PXR and its potential roles in multidrug resistance and the biological characteristics of PXR-positive tumors.

Breast cancer is one of the most common malignancies in women. This study was conducted to analyze the association between the expressions of eight immunohistochemical (IHC) indices and clinicopathological characteristics in breast cancers (BCs) and investigate the clinical significance. IHC Envision ldpe-g-nvp was used to detect the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), p53, type II topoisomerase (TOPO II) and Ki-67 in postoperative paraffin blocks of 286 cases of invasive BC and statistically analyzed their correlations with clinicopathological characteristics. The positive rates of ER, PR, HER2, VEGF, p53, EGFR, TOPO II and Ki-67 expression were 62.24, 41.96, 57.34, 53.85, 81.82, 46.85, 54.55 and 69.93%, respectively. ER expression was negatively correlated with age, tumor size and histological grade (P<0.05) and PR expression was negatively correlated with age and histological grade (P<0.05). Among the ER, PR and c-erbB-2 statuses, a significant correlation was observed between ER expression and PR status (P=0.0000), whereas the expression of ER and PR exhibited a negative correlation with HER2 status (P<0.05). We also demonstrated a significant correlation between EGFR expression and lymph node metastasis (P=0.0240), p53 expression and tumor size (P=0.0300), p53 and Ki-67 expression and histological grade (P<0.05) and the expressions of VEGF, EGFR, p53, TOPO II, Ki-67 and HER2 status (P<0.05). In addition, the Luminal B and HER2/neu subtypes exhibited a close correlation with age (P<0.01), while the HER2/neu and triple-negative subtypes were positively correlated with poor histological grade (P<0.05). In conclusion, there is a definite correlation between IHC indices and clinicopathological characteristics in BCs. Combined detection of these indices may be significant in the evaluation of biological behavior and prognosis of BC and thus in the diagnosis and comprehensive treatment of this disease.

Background: There is still a great deal of controversy with regard to the prognostic role of chemotherapyinduced amenorrhea (CIA) in breast cancer patients. To confirm whether CIA can serve as a useful factor in predicting clinical effects of systemic adjuvant chemotherapy, we performed this meta-analysis. Materials and Methods: Relevant studies were identified using PubMed, and Embase databases. Eligible study results were pooled and summary hazard ratios (HRs) with corresponding confidence intervals (CIs) were calculated. Subgroup analyses and an assessment of publication bias were also conducted. Results: A total of 8,333 patients from 11 published studies were identified through searching the databases. The pooled HRs for disease-free survival (DFS) suggested that CIA was associated with a significant reduction in the risk of recurrence, especially in patients with hormone receptor-positive lesions (overall HR=0.65, 95%CI 0.53-0.80, I 2 = 41.3%). When the five studies reporting the HR for overall survival (OS) were pooled (n=4193), a favorable trend was found (HR=0.69, 95%CI 0.52-0.91, I 2 = 51.6%). No publication bias was observed in this study. Conclusions: This meta-analysis suggests that CIA predicts a better outcome in premenopausal hormone receptor-positive breast cancer patients.

Circular RNAs are an important kind of noncoding RNAs and involved in cancerogenesis, but the specific mechanism between gastric cancer and circRNAs needs further study. Hsa_circ_0007967 was selected by RNA sequencing. Here, hsa_circ_0007967 was highly expressed in gastric cancer tissues than adjacent normal tissues. Overexpressing hsa_circ_0007967 promoted gastric cancer cell proliferation in vitro and in vivo, while suppression of hsa_circ_0007967 inhibited gastric cancer cell proliferation in vitro and in vivo. Mechanistically, hsa_circ_0007967 sponged miR-411-5p to increase MAML3 expression. Overall, hsa_circ_0007967 is a promising biomarker for gastric cancer diagnosis and a potential molecule for gastric cancer treatment.