BackgroundPatients with irritable bowel syndrome (IBS) have significantly reduced quality of life (QOL). Although intestinal and extraintestinal symptoms, as well as comorbid psychological disorders, may reduce the QOL of IBS patients, the primary determinant of QOL in these patients remains unclear. This study aimed to identify the main factors affecting QOL in patients with IBS with diarrhea (IBS-D).MethodsConsecutive patients meeting the Rome III Diagnostic Criteria for IBS-D were enrolled in this study. Patients with organic diseases were excluded. The intestinal symptoms, psychological states and QOL of these patients were evaluated using IBS-specific symptom questionnaires, the Hamilton Depression Scale (HAMD), the Hamilton Anxiety Scale (HAMA), and the Chinese version of the IBS-QOL instrument. Overall scores for intestinal symptoms were calculated by frequency and degree.ResultsThis study enrolled 227 IBS-D patients, of mean age 44.68 ± 10.81 years. Their mean overall IBS-QOL score was 71.68 ± 18.54, with the lowest score being for food avoidance (53.71 ± 26.92). Overall IBS-QOL score correlated negatively with overall scores of intestinal symptoms and HAMD and HAMA scores (p < 0.001 each). Overall intestinal symptoms scores correlated negatively with HAMD and HAMA scores (p < 0.001 each). Scores of HAMD, HAMA and structural factors (i.e., anxiety/somatization, cognitive disorder, psychomotor retardation, psychic anxiety, and somatic anxiety) were significantly higher in female than in male patients (p < 0.01). Food avoidance and social reaction scores of female patients were significantly lower than those of male patients (p < 0.05 each). The degree of defecation urgency, frequency of passing mucus and psychomotor retardation were independent factors predicting reduced QOL in IBS-D patients.ConclusionIntestinal symptoms and psychological factors jointly reduce the QOL of IBS-D patients, with gender differences in the impact of both factors on QOL.

Chemoresistance is responsible for most colorectal cancer (CRC) related deaths. In this study, we found that dichloroacetate (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, can be used as a sensitizer for oxaliplatin (L-OHP) chemoresistant CRC cells. The aim of this study was to explore the ability of DCA to overcome L-OHP resistance in CRC cells and to identify the underlying molecular mechanisms. We found that DCA sensitizes chemoresistant CRC cells to L-OHP-induced cytotoxic effects by inhibiting clone formation capacity and promoting cell apoptosis. A microRNA (miRNA) array was used for screen, and miR-543 was identified and shown to be downregulated after DCA treatment. The expression of miR-543 was higher in chemoresistant CRC cells than in chemosensitive CRC cells. Overexpression of miR-543 increased chemoresistance in CRC cells. The validated target gene, PTEN, was negatively regulated by miR-543 both in vitro and in vivo, and PTEN was upregulated by DCA through miR-543. In addition, overexpression of miR-543 reversed the inhibition of colony formation after DCA treatment. Furthermore, the Akt/mTOR pathway is activated by miR-543 and is involved in the miR-543 induced chemoresistance. There was a significant inverse relationship between miR-543 expression and PTEN level in CRC patients, and high miR-543 expression was associated with worse prognosis. In conclusion, DCA restored chemosensitivity through miR-543/PTEN/Akt/mTOR pathway, and miR-543 may be a potential marker or therapeutic target for chemoresistance in CRC.

The development of chemoresistance remains a major challenge that accounts for colorectal cancer (CRC) lethality. Dichloroacetate (DCA) was originally used as a metabolic regulator in the treatment of metabolic diseases; here, DCA was assayed to identify the mechanisms underlying the chemoresistance of CRC. We found that DCA markedly enhanced chemosensitivity of CRC cells to fluorouracil (5-FU), and reduced the colony formation due to high levels of apoptosis. Using the microarray assay, we noted that miR-149-3p was involved in the chemoresistance of CRC, which was modulated by wild-type p53 after DCA treatment. In addition, PDK2 was identified as a direct target of miR-149-3p. Mechanistic analyses showed that overexpression of miR-149-3p enhanced 5-FU-induced apoptosis and reduced glucose metabolism, similar to the effects of PDK2 knockdown. In addition, overexpression of PDK2 partially reversed the inhibitory effect of miR-149-3p on glucose metabolism. Finally, both DCA treatment and miR-149-3p overexpression in 5-FU-resistant CRC cells were found to markedly sensitize the chemotherapeutic effect of 5-FU in vivo, and this effect was also validated in a small retrospective cohort of CRC patients. Taken together, we determined that the p53/miR-149-3p/PDK2 signaling pathway can potentially be targeted with DCA treatment to overcome chemoresistant CRC.