Gut microbiome affects the response to immunotherapy in non-small cell lung cancer.

BACKGROUND: Immunotherapy has revolutionized cancer treatment. Recent studies have suggested that the efficacy of immunotherapy can be further enhanced by the influence of gut microbiota. In this study, we aimed to investigate the impact of bacteria on the effectiveness of cancer immunotherapy by combining analysis of clinical samples with validation in animal models. METHODS: In order to characterize the diversity and composition of microbiota and its relationship with response to immune checkpoint inhibitors (ICIs), 16S ribosomal RNA (rRNA) and GC-MS sequencing was performed on 71 stool samples from patients with advanced non-small cell lung cancer (NSCLC) prior to treatment with immune checkpoint blockade (ICB). Furthermore, fecal microbiota transplantation (FMT) was performed from different patients into mice and a subcutaneous tumor model established using the Lewis lung cancer cell line to evaluate the therapeutic effect of PD-1 on mice with varying gut microbiota. RESULTS: The results demonstrated a significant association between elevated gut microbiota diversity and response to treatment with ICIs, p < 0.05. Faecalibacterium was markedly increased in the gut microbiota of responders (R), accompanied by increased short-chain fatty acid (SCFA) levels, especially butanoic acid, acetic acid and hexanoic acid, p < 0.05. Additionally, FMT from R and nonresponders (NR) could promote an anticancer effect and reduce the expression of Ki-67 cells in tumors in mice, p < 0.05. Moreover, R and NR FMT did not alter PD-L1 expression in the tumor tissues of mice, p > 0.05. The diversity of gut microbiota consistently correlated with an optimistic prognosis in NSCLC patients with immunotherapy, which could be functionally mediated by SCFAs. CONCLUSION: The findings of the present study indicated that the diversity of gut microbiota and SCFAs is related to the efficacy of immunotherapy. FMT can effectively delay tumor progression, and enhance the effect of immunotherapy, thus providing evidence for improving the efficacy of immunotherapy in NSCLC patients.

PDZK1 suppresses TNBC development and sensitizes TNBC cells to erlotinib via the EGFR pathway.

Epidermal growth factor receptor (EGFR)-targeted drugs (erlotinib, etc.) are used to treat multiple types of tumours. EGFR is highly expressed in most triple-negative breast cancer (TNBC) patients. However, only a small proportion of TNBC patients benefit from EGFR-targeted drugs in clinical trials, and the resistance mechanism is unclear. Here, we found that PDZ domain containing 1 (PDZK1) is downregulated in erlotinib-resistant TNBC cells, suggesting that PDZK1 downregulation is related to erlotinib resistance in TNBC. PDZK1 binds to EGFR. Through this interaction, PDZK1 promotes EGFR degradation by enhancing the binding of EGFR to c-Cbl and inhibits EGFR phosphorylation by hindering EGFR dimerisation. We also found that PDZK1 is specifically downregulated in TNBC tissues and correlated with a poor prognosis in TNBC patients. In vitro and in vivo functional assays showed that PDZK1 suppressed TNBC development. Restoration of EGFR expression or kinase inhibitor treatment reversed the degree of cell malignancy induced by PDZK1 overexpression or knockdown, respectively. PDZK1 overexpression sensitised TNBC cells to erlotinib both in vitro and in vivo. In conclusion, PDZK1 is a significant prognostic factor for TNBC and a potential molecular therapeutic target for reversing erlotinib resistance in TNBC cells.

Safety and efficacy of tight versus loose glycemic control in acute stroke patients: A meta-analysis of randomized controlled trials.

BACKGROUND: Hyperglycemia is associated with worse stroke outcomes, but it is uncertain whether tight glycemic control during the acute stroke period is associated with a better outcome. We conducted a meta-analysis to compare the effect of tight glycemic control versus loose glycemic control in the acute phase of stroke patients. METHODS: A literature search was performed to identify randomized controlled trials comparing the safety and efficacy of tight glycemic control with a relatively loose control of blood glucose of acute stroke (ischemic or hemorrhagic) patients within 24 h after stroke onset. We required that the blood glucose level of the patients should not be lower than 6.11 mmol/L at the time of enrollment, and for the intensive blood glucose control range, we defined the blood glucose level as lower than that of the control group. The primary efficacy outcome measure was deaths from any cause at 90 days. Secondary efficacy outcomes comprised the number of participants with modified Rankin score (mRS). We define mRS scores 0-2 as favorable scores, recurrent stroke, and the National Institute of Health Stroke Scale or the European Stroke Scale scores. We defined the number of participants with hypoglycemia as our primary safety outcome. Subgroup analysis was performed according to age, the variety of interventions, maintained glucose level, and status of hypoglycemia on National Institute of Health Stroke Scale (NIHSS) scores or European Stroke Scale (ESS) scores. RESULTS: Fifteen randomized controlled trials (RCTs) with 2957 participants meeting the including criteria were identified and included in this meta-analysis, although not all included data on every outcome measure. Data on the primary efficacy endpoint, mortality at 90 days, was available in 11 RCTs, a total of 2575 participants. There was no significant difference between the intervention and control groups (odds ratio (OR): 1.00; 95% confidence interval (CI): 0.81-1.23; P = 0.99). For secondary endpoints, there was no difference between intervention and control groups for a mRS from 0 to 2 (OR: 0.96; 95% CI: 0.80-1.15; P = 0.69; data from 9 RCTs available), or recurrent stroke (OR: 1.34; 95% CI: 0.92-1.96; P = 0.13; data from 3 RCTs available). For NIHSS scores or ESS scores, there was a small difference in favor of intensive controls (standardized mean difference: -0.29; 95% CI: -0.54 to -0.04; P = 0.02). There was a marked increase in hypoglycemia with tight control: (OR of 9.46 (95% CI: 4.59-19.50; P < 0.00001; data from 9 RCTs available). CONCLUSION: There was no difference between tight and loose glycemic control on mortality, independence, or recurrent stroke outcome in acute stroke, but an increase in hypoglycemia. There was a small effect improvement on neurological scales, but the relevance of this needs to be confirmed in future adequately powered studies.