Homologous recombination repair gene mutations as a predictive biomarker for immunotherapy in patients with advanced melanoma.

Background: Nowadays, immunotherapy targeting immune checkpoint receptors is one of the cornerstones of systemic treatment in melanoma. Homologous recombination repair (HRR) is one of the DNA damage response (DDR) pathways, which has been proved to correlate with the efficacy of platinum-based chemotherapy, PARP inhibitor therapy, and immunotherapy in a variety of cancers. However, their predictive value of HRR remained unknown in patients with advanced melanoma. Methods: Data of advanced melanoma patients from an independent cohort (Samstein2018) were used to analyze the correlation with immunogenic markers and the prognostic effect of HRR on immunotherapy, and another four cohorts (pooled cohort: Miao2018, Allen 2015, Hugo2016, and Synder2014) were used for validation. Immune infiltration cell scores analyzed by TCGA-SKCM cohort were used to explore potential mechanisms related to the immune microenvironment. Results: Compared to patients with an HRR wild type (HRRwt), those with HRR mutations (HRRmut) in anti-CTLA-4-treated patients of the Samstein2018 cohort had higher tumor mutation burden (TMB; P = 0.0041) and longer median overall survival (mOS; P = 0.0094). In terms of results validation, it was also confirmed that the mOS (P = 0.0014) of HRRmut patients receiving anti-CTLA-4 therapy was significantly better than that of HRRwt patients in the pooled cohort, and objective response rates (ORR; P = 0.0053) were also found to be significant. However, there was no significant difference in mOS between HRRmut patients who received anti-PD-1/L1 therapy and HRRwt patients in either the discovery (Samstein2018 cohort, P = 0.94) or validation (pooled cohort, P = 0.96) set. Exploratory analysis found that although HRRmut patients showed no significant difference in mOS between anti-CTLA-4 and anti-PD-1/L1 therapy (P = 0.79), the mOS value of the anti-CTLA-4 therapy group (31.7 months) in HRRmut patients was numerically superior to the anti-PD-1/L1 therapy group (27.5 months). In contrast, the mOS of the anti-CTLA-4 therapy group was significantly lower than that of the anti-PD-1/L1 therapy group (12.4 vs. 32.0 months) in HRRwt patients. In addition, transcriptome profiling analysis revealed that the 29 (65.9%)-gene mutation of the HRR pathway associated with reshaping of the immunological microenvironment in melanoma. Conclusions: HRR mutations were associated with a higher TMB level, and better anti-CTLA-4 therapy outcomes. HRR may serve as an independent predictor of anti-CTLA-4 therapy efficacy in patients with advanced melanoma and their clinical value warrants further investigation.

Combination of Circulating miR-125a-5p, miR-223-3p and D-dimer as a Novel Biomarker for Deep Vein Thrombosis.

BACKGROUND: Deep venous thrombosis (DVT) is a thrombus formed in the deep venous cavity and can cause a fatal pulmonary embolism. Since circulating miRNAs are used as molecular markers for the early warning and diagnosis of various diseases, such as tumors and cardiovascular diseases, the purpose of the present study was initially to identify differential expression circulating miRNAs in plasma, and then explore potential biomarkers for DVT. METHODS: The plasma of 30 patients with DVT before and after DVT-related endovascular interventions constituted 6 sample pools for miRNA sequencing, and the levels of 22 plasma miRNAs were significantly changed. Then, various bioinformatics tools were utilized to screen out 8 miRNAs with potential DVT diagnostic value. Furthermore, their diagnostic values were evaluated in 120 patients with DVT and 120 healthy individuals. RESULTS: The levels of 22 circulating plasma miRNAs (12 up-regulated, 10 down-regulated) were significantly changed in patients with DVT before and after endovascular interventions, especially miR-125a-5p (up-regulation) and miR-223-3p (down-regulation). The values of area under the ROC curve (AUC) of miR-125a-5p and miR-223-3p were both >0.8, indicating that they were valuable in diagnosing DVT. The combination of miR-125a-5p and miR-223-3p with D-dimer significantly improved the efficiency of diagnosing DVT, (AUC >0.97, the sensitivity and specificity >95%), and was better than those of D-dimer alone. CONCLUSIONS: The levels of miR-125a-5p and miR-223-3p were the most significantly changed in patients with DVT before and after endovascular interventions; together with the classic biomarker D-dimer, they can be used as a potential biomarker for diagnostic and therapeutic process of DVT.

miR-181c-5p mediates apoptosis of vascular endothelial cells induced by hyperoxemia via ceRNA crosstalk.

Oxygen therapy has been widely used in clinical practice, especially in anesthesia and emergency medicine. However, the risks of hyperoxemia caused by excessive O2 supply have not been sufficiently appreciated. Because nasal inhalation is mostly used for oxygen therapy, the pulmonary capillaries are often the first to be damaged by hyperoxia, causing many serious consequences. Nevertheless, the molecular mechanism by which hyperoxia injures pulmonary capillary endothelial cells (LMECs) has not been fully elucidated. Therefore, we systematically investigated these issues using next-generation sequencing and functional research techniques by focusing on non-coding RNAs. Our results showed that hyperoxia significantly induced apoptosis and profoundly affected the transcriptome profiles of LMECs. Hyperoxia significantly up-regulated miR-181c-5p expression, while down-regulated the expressions of NCAPG and lncRNA-DLEU2 in LMECs. Moreover, LncRNA-DLEU2 could bind complementarily to miR-181c-5p and acted as a miRNA sponge to block the inhibitory effect of miR-181c-5p on its target gene NCAPG. The down-regulation of lncRNA-DLEU2 induced by hyperoxia abrogated its inhibition of miR-181c-5p function, which together with the hyperoxia-induced upregulation of miR-181c-5p, all these significantly decreased the expression of NCAPG, resulting in apoptosis of LMECs. Our results demonstrated a ceRNA network consisting of lncRNA-DLEU2, miR-181c-5p and NCAPG, which played an important role in hyperoxia-induced apoptosis of vascular endothelial injury. Our findings will contribute to the full understanding of the harmful effects of hyperoxia and to find ways for effectively mitigating its deleterious effects.

MiR-363-5p modulates regulatory T cells through STAT4-HSPB1-Notch1 axis and is associated with the immunological abnormality in Graves' disease.

MiRNAs are a class of small non-coding RNAs with ability to regulate function of Treg cells and are involved in many autoimmune diseases. Our previous study found that miR-363-5p expression was significantly upregulated in peripheral Treg cells of GD patients. Herein, we aimed to investigate its effect and mechanism on Treg cell dysfunction in GD patients. The results showed that miR-363-5p upregulation was significantly associated with the Treg cell dysfunction and inflammatory factors levels in GD patients. Transcriptome sequencing revealed that 883 genes were significantly regulated by miR-363-5p in Treg cells. These genes with significant differential expression were primarily involved in lymphocyte differentiation, immunity, as well as Notch1 and various interleukin signalling pathways. Moreover, miR-363-5p can regulate HSPB1 and Notch1 through the target gene STAT4, thereby regulating Notch1 signalling pathway and inhibiting Treg cells. The effects of miR-363-5p on Treg cell function and STAT4-HSPB1-Notch1 axis were also verified in GD patients. In conclusion, our results indicated that miR-363 could inhibit the proliferation, differentiation and function of Treg cells by regulating the STAT4-HSPB1-Notch1 axis through target gene STAT4. MiR-363-5p may play an important role in Treg cell dysfunction and immune tolerance abnormalities in GD patients.

Let-7e modulates the inflammatory response in vascular endothelial cells through ceRNA crosstalk.

The inflammatory responses of vascular endothelial cells (VECs) are critical in the development of many cardio-cerebrovascular diseases. Let-7e is an important regulator of endothelial function and inflammation. However, the effects and mechanisms of let-7e on VECs inflammation have not been studied until recently. Thus, we investigated these issues and found that in addition to proliferation, apoptosis and cell adhesion, let-7e was also implicated in the regulation of inflammatory responses through a complex network, including IκBß and lncRNA lnc-MKI67IP-3. Let-7e promoted NF-κB activation and translocation to the nucleus by inhibiting its target gene (IκBß) expression and subsequently increased the expression of inflammatory and adhesion molecules. Meanwhile, lnc-MKI67IP-3 acted as a sponge or competing endogenous RNA (ceRNA) for let-7e, suppressing its pro-inflammatory effects, and let-7e decreased lnc-MKI67IP-3 expression, thereby forming a positive feedback loop to aggravate inflammation. Moreover, let-7e, lnc-MKI67IP-3 and IκBß were also abnormal in oxLDL-treated VECs and atherosclerotic plaques. The present study revealed let-7e as a pro-inflammatory mediator and a novel regulatory mechanism for the NF-κB pathway through ceRNA crosstalk, comprising let-7e and its target IκBß and the ceRNA lnc-MKI67IP-3. Thus, this molecule might play important roles in the inflammatory responses of VECs and development of atherosclerosis.