[Research Advances of RAD51AP1 in Tumor Progression and Drug Resistance].

The genomic instability may lead to an initiation of cancer in many organisms. Homologous recombination repair (HRR) is vital in maintaining cellular genomic stability. RAD51 associated protein 1 (RAD51AP1), which plays a crucial role in HRR and primarily participates in forming D-loop, was reported as an essential protein for maintaining cellular genomic stability. However, recent studies showed that RAD51AP1 was significantly overexpressed in various cancer types and correlated with poor prognosis. These results suggested that RAD51AP1 may play a significant pro-cancer effect in multiple cancers. The underlying mechanism is still unclear. Cancer stemness-maintaining effects of RAD51AP1 might be considered as the most reliable mechanism. Meanwhile, RAD51AP1 also promoted resistance to radiation therapy and chemotherapy in many cancers. Thus, researches focused on RAD51AP1, and its regulatory molecules may provide new targets for overcoming cancer progression and treatment resistance. Here, we reviewed the latest research on RAD51AP1 in cancers and summarized its differential expression and prognostic implications. In this review, we also outlined the potential mechanisms of its pro-cancer and drug resistance-promoting effects to provide several potential directions for further research.
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Splenic monocytes mediate inflammatory response and exacerbate myocardial ischemia/reperfusion injury in a mitochondrial cell-free DNA-TLR9-NLRP3-dependent fashion.

The spleen contributes importantly to myocardial ischemia/reperfusion (MI/R) injury. Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) recruits inflammasomes, initiating inflammatory responses and mediating tissue injury. We hypothesize that myocardial cell-free DNA (cfDNA) activates the splenic NLRP3 inflammasome during early reperfusion, increases systemic inflammatory response, and exacerbates myocardial infarct. Mice were subjected to 40 min of ischemia followed by 0, 1, 5, or 15 min, or 24 h of reperfusion. Splenic leukocyte adoptive transfer was performed by injecting isolated splenocytes to mice with splenectomy performed prior to left coronary artery occlusion. CY-09 (4 mg/kg) was administered 5 min before reperfusion. During post-ischemic reperfusion, splenic protein levels of NLRP3, cleaved caspase-1, and interleukin-1ß (IL-1ß) were significantly elevated and peaked (2.1 ± 0.2-, 3.4 ± 0.4-, and 3.2 ± 0.2-fold increase respectively, p < 0.05) within 5 min of reperfusion. In myocardial tissue, NLRP3 was not upregulated until 24 h after reperfusion. Suppression by CY09, a specific NLRP3 inflammasome inhibitor, or deficiency of NLRP3 significantly reduced myocardial infarct size (17.3% ± 4.2% and 33.2% ± 1.8% decrease respectively, p < 0.01). Adoptive transfer of NLRP3-/- splenocytes to WT mice significantly decreased infarct size compared to transfer of WT splenocytes (19.1% ± 2.8% decrease, p < 0.0001). NLRP3 was mainly activated at 5 min after reperfusion in CD11b+ and LY6G- splenocytes, which significantly increased during reperfusion (24.8% ± 0.7% vs.14.3% ± 0.6%, p < 0.0001). The circulating cfDNA level significantly increased in patients undergoing cardiopulmonary bypass (CPB) (43.3 ± 5.3 ng/mL, compared to pre-CPB 23.8 ± 3.5 ng/mL, p < 0.01). Mitochondrial cfDNA (mt-cfDNA) contributed to NLRP3 activation in macrophages (2.1 ± 0.2-fold increase, p < 0.01), which was inhibited by a Toll-like receptor 9(TLR9) inhibitor. The NLRP3 inflammasome in splenic monocytes is activated and mediates the inflammatory response shortly after reperfusion onset, exacerbating MI/R injury in mt-cfDNA/TLR9-dependent fashion. The schema reveals splenic NLRP3 mediates the inflammatory response in macrophages and exacerbates MI/R in a mitochondrial cfDNA/ TLR9-dependent fashion.

Neutrophil infiltration associated genes on the prognosis and tumor immune microenvironment of lung adenocarcinoma.

The neutrophils exhibit both anti-tumor and pro-tumor effects in cancers. The correlation between neutrophils and tumor development in lung adenocarcinoma (LUAD) is still uncertain, possibly due to a lack of specific neutrophil infiltration evaluation methods. In this study, we identified 30 hub genes that were significantly associated with neutrophil infiltration in LUAD through data mining, survival analysis, and multiple tumor-infiltrating immune cells (TICs) analysis, including TIMER, CIBERSORT, QUANTISEQ, XCELL, and MCPCOUNTER. Consensus clustering analysis showed that these 30 hub genes were correlated with clinical features in LUAD. We further developed a neutrophil scoring system based on these hub genes. The neutrophil score was significantly correlated with prognosis and tumor immune microenvironment (TIME) in LUAD. It was also positively associated with PD-L1 expression and negatively associated with tumor mutational burden (TMB). When combined with the neutrophil score, the predictive capacity of PD-L1 and TMB for prognosis was significantly improved. Thus, the 30 hub genes might play an essential role in the interaction of neutrophils and LUAD, and the neutrophil scoring system might effectually assess the infiltration of neutrophils. Furthermore, we verified the expression of these 30 genes in the LUAD tumor tissues collected from our department. We further found that overexpressed TNFAIP6 and TLR6 and downregulated P2RY13, SCARF1, DPEP2, PRAM1, CYP27A1, CFP, GPX3, and NCF1 in LUAD tissue might be potentially associated with neutrophils pro-tumor effects. The following in vitro experiments demonstrated that TNFAIP6 and TLR6 were significantly overexpressed, and P2RY13 and CYP27A1 were significantly downregulated in LUAD cell lines, compared to BEAS-2B cells. Knocking down TNFAIP6 in A549 and PC9 resulted in the upregulation of FAS, CCL3, and ICAM-1, and the downregulation of CCL2, CXCR4, and VEGF-A in neutrophils when co-culturing with the conditioned medium (CM) from LUAD cells. Knocking down TNFAIP6 in LUAD also led to an elevated early apoptosis rate of neutrophils. Therefore, overexpressed TNFAIP6 in LUAD cancer cells might lead to neutrophils "N2" polarization, which exhibited pro-tumor effects. Further research based on the genes identified in this pilot study might shed light on neutrophils' effects on LUAD in the future.

Systematic pan-cancer analysis showed that RAD51AP1 was associated with immune microenvironment, tumor stemness, and prognosis.

Although RAD51 associated protein 1 (RAD51AP1) is crucial in genome stability maintenance, it also promotes cancer development with an unclear mechanism. In this study, we collected intact expression data of RAD51AP1 from the public database, and verified it was significantly over-expressed in 33 cancer types and correlated with poor prognosis in 13 cancer types, including glioma, adrenocortical carcinoma, lung adenocarcinoma. We further authenticated that RAD51AP1 is up-regulated in several typical cancer cell lines and promotes cancer cell proliferation in vitro. Moreover, we also demonstrated that RAD51AP1 was significantly positively related to cancer stemness score mRNAsi in 27 cancer types and broadly correlated to tumor-infiltrating immune cells in various cancers in a diverse manner. It was also negatively associated with immunophenoscore (IPS) and Estimation of STromal and Immune cells in MAlignant Tumours using Expression data (ESTIMATE) scores and positively correlated with mutant-allele tumor heterogeneity (MATH), tumor mutational burden (TMB), microsatellite instability (MSI), and PD-L1 expression in multiple cancers. The tumor stemness enhancing and tumor immune microenvironment affecting functions of RAD51AP1 might compose its carcinogenesis mechanism. Further investigations beyond the bioinformatics level should confirm these findings in each specific cancer.

Genomic analysis of TNF-related genes with prognosis and characterization of the tumor immune microenvironment in lung adenocarcinoma.

Background: The tumor necrosis factor (TNF) family plays a role in modulating cellular functions that regulate cellular differentiation, survival, apoptosis, and especially cellular immune functions. The TNF family members also play important roles in oncogenesis and progression. However, the potential role of the TNF family members in lung adenocarcinoma (LUAD) is yet to be explored. Methods: The expression of TNF-related genes (TNFRGs) in 1,093 LUAD samples was investigated using The Cancer Genome Atlas and Gene Expression Omnibus datasets. The characteristic patterns of TNFRGs in LUAD were systematically probed and three distinct molecular subtypes were identified. Furthermore, a correlation was found between the different subtypes and their clinical characteristics. A TNF scoring system was created to predict overall survival (OS) and therapeutic responses in patients with LUAD. Subsequently, the predictive accuracy of the score was verified and a nomogram was used to optimize the clinical applicability range of the TNF score. Results: A high TNF score, involving the immune and stromal scores, indicated negative odds of OS. Moreover, the TNF score was associated with immune checkpoints and chemotherapeutic drug sensitivity. Collectively, our comprehensive TNFRGs analysis of patients with LUAD revealed that TNF could be involved in forming the diverse and complex tumor microenvironment, its clinicopathological features, and its prognosis. Conclusions: A TNF-related prognostic model was constructed, and a TNF score was developed. These findings are expected to improve our knowledge regarding the function of TNFRGs in LUAD, pave a new path for assessing the disease prognosis, and assist in developing personalized therapeutic strategies for patients with LUAD.

Survival Benefits for Pulmonary Adenocarcinoma With Malignant Pleural Effusion After Thoracoscopic Surgical Treatment: A Real-World Study.

Objectives: Malignant cells in the pleural fluid or pleural metastasis are classified as stage IV non-small cell lung cancer. Radical surgery is generally considered not suitable for such patients. The aim of our study was to discuss the effectiveness of video-assisted thoracoscopic surgery (VATS) in such patients. Methods: A retrospective analysis of the clinical records of 195 patients was performed. These patients were all diagnosed with locally advanced pulmonary adenocarcinomas with malignant pleural effusion (MPE, M1a) but no distant organ metastasis. The 195 patients included 96 patients who underwent VATS plus chemotherapy and 99 patients who received thoracic drainage plus chemotherapy. The baseline characteristics of the patients included age, gender, smoking history, Eastern Cooperative Oncology Group (ECOG) score, and number of chemotherapy cycles (2-4 cycles or >4 cycles); we also analyzed clinical characteristics including the specific surgical options of the VATS group. Results: In multivariate analysis, when compared to the thoracic drainage group, the VATS group remained significantly associated with the overall survival [HR=0.480 (95%CI 0.301-0.765)]; when compared to the lobectomy, the sub-lobectomy and the palliative surgery, remained significantly associated with the overall survival [HR=0.637 (95%CI 0.409-0.993) and HR=0.548 (95%CI 0.435-0.832), respectively]. The median survival time (MST) of patients who underwent VATS (n = 96, 49.2%) was 25 months (95% CI 22.373-27.627) whereas the patients who received thoracic drainage (n = 99, 50.8%) was 11 months (95% CI 9.978-12.022). For patients who underwent VATS, the MST of patients who received a lobectomy (n = 50, 52.1%) was 27 months (95% CI 22.432-31.568), the MST of patients who received a sub-lobectomy plus pleurodesis (n = 26, 27.1%) was 27 months (95% CI 19.157-34.843), and the MST of patients who received only pleurodesis (n = 20, 20.8%) was 12 months (95% CI 7.617-16.383). Conclusion: For pulmonary adenocarcinomas with MPE, receiving a lobectomy or sub-lobectomy plus pleurodesis with VATS was associated with improved survival compared with patients who only received thoracic drainage and chemotherapy. Our results and previously published data may justify the use of VATS for treating pulmonary adenocarcinomas with MPE.

Nrf2 participates in the protective effect of exogenous mitochondria against mitochondrial dysfunction in myocardial ischaemic and hypoxic injury.

OBJECTIVE: Coronary artery disease is one of the leading causes of death worldwide. Treatments including coronary artery intervention can cause complications, such as myocardial ischaemia-reperfusion injury (MIRI). Mitochondrial injury or dysfunction is a key pathology of MIRI. Mitochondrial transplantation is considered a promising therapeutic strategy for cardiac-related diseases, but its mechanism is still unclear. Nrf2 is a prominent player in supporting the structural and functional integrity of mitochondria. In our research, we focused on the effect of Nrf2 in the treatment of MIRI by mitochondrial transplantation. H9C2 cells were subjected to hypoxia/reoxygenation (H/R) and MIRI was induced in wild-type and Nrf2-/- mice by surgical ligation of the left coronary artery to elucidate the mechanism in vitro and in vivo, respectively. Exogenous mitochondria were extracted from healthy H9C2 cells and the pectoralis major and administered to H9C2 cells and mice with MIRI, respectively. Mitochondrial internalization, H9C2 cell injury or apoptosis, cardiac injury/function, mitochondrial function, morphology, mitochondrial dynamics, and the expression of components of the Nrf2 pathway were assessed. We found that exogenous mitochondria were internalized into H9C2 cardiomyocytes. Exogenous mitochondrial transplantation attenuated cardiomyocyte injury, cardiomyocyte apoptosis, and mitochondrial dysfunction. Exogenous mitochondrial transplantation increased the expression of Nrf2 and its downstream targets, attenuated cardiomyocyte injury, cardiac dysfunction, apoptosis, mitochondrial dysfunction, and mitochondrial fusion and fission imbalance, and improved mitophagy after MIRI in wild-type mice but not in Nrf2-/- mice. These results suggested that exogenous mitochondria can be internalized into cardiomyocytes and activate the Nrf2 pathway and that exogenous mitochondria improve cardiac function and ameliorate mitochondrial dysfunction via the Nrf2 pathway.

MicroRNA-34c Inhibits Osteogenic Differentiation and Valvular Interstitial Cell Calcification via STC1-Mediated JNK Pathway in Calcific Aortic Valve Disease.

Calcific aortic valve disease (CAVD), a common heart valve disease, is increasingly prevalent worldwide and causes high morbidity and mortality. Here, we aimed to investigate a possible role for miR-34c in the development of osteogenic differentiation during CAVD and to find out the underlying mechanisms. Valvular interstitial cells (VICs) were isolated from the clinical aortic valve tissue samples of CAVD patients and patients with acute aortic dissection and collected. Then, RT-qPCR was performed to determine miR-34c expression and western blot analysis was applied to confirm the relevant protein expression in these VICs. Dual luciferase reporter gene assay was applied to confirm the relation between miR-34c and STC1. Alkaline phosphatase (ALP) staining and alizarin red staining was performed to further confirm the degree of calcification in these samples. MiR-34c was lowly expressed and STC1 was highly expressed in the CAVD tissues. Furthermore, STC1 was the target of miR-34c and was negatively regulated by miR-34c. Overexpression of miR-34c in VICs was concomitant with suppression of both STC1 expression and phosphorylation level of c-Jun N-terminal kinase (JNK). In addition, significant decrease of bone morphogenetic protein-2 (BMP2) and osteocalcin, as well as the decrease of calcification degree were also observed in VICs with miR-34c overexpressed. Taken together, miR-34c could inhibit osteogenic differentiation and calcification of VICs by suppressing the STC1/JNK signaling pathway in CAVD, making miR-34c a novel therapeutic target for the treatment of CAVD.

Upregulation of microRNA-195 ameliorates calcific aortic valve disease by inhibiting VWF via suppression of the p38-MAPK signaling pathway.

BACKGROUND: Growing evidence has indicated that microRNAs (miRNAs) are involved in the progression of calcific aortic valve disease (CAVD), a progressive pathological condition with no effective pharmacological therapy. This study was set out with the aim to investigate possible roles of miR-195 in CAVD. METHODS AND RESULTS: Initially, the differential expressed genes (DEGs) associated with CAVD were screened out and miRNAs potentially regulating VWF were predicted from microarray analysis. Next, we quantified VWF and miR-195 expression in isolated aortic valve interstitial cells (AVICs) and aortic valve tissues, followed by confirmation of the target relationship between miR-195 and VWF using the dual luciferase reporter assay. Furthermore, we evaluated the biological functions of miR-195 and VWF on ALP activity, cell differentiation, and the levels of miR-195, VWF, Runx2, OCN, ALP, p38 and phosphorylated p38 in AVICs. VWF was highly expressed, while miR-195 was poorly expressed in CAVD. Furthermore, miR-195 targeted VWF and negatively regulated its expression. Upregulation of miR-195 or silencing VWF could reduce ALP activity, calcified deposition, and the mRNA and protein levels of Runx2, OCN, and ALP by inhibiting the p38-MAPK signaling pathway, thereby ameliorating aortic valve calcification in vitro. CONCLUSIONS: On all accounts, miR-195 can potentially inhibit aortic valve calcification by repressing VWF and p38-MAPK signaling pathway, highlighting a theoretical basis for pharmacological treatment of CAVD.

Clinical implication of MEN1 mutation in surgically resected thymic carcinoid patients.

Thymic carcinoid is a rare but very aggressive neuroendocrine tumour derived from the neuroendocrine system. Here we report a male patient with thymic atypical carcinoid. Though thymic carcinoid is relatively common, the gene sequencing profile was performed and the gene sequencing result indicated germline multiple endocrine neoplasia type 1 (MEN1) mutation and two somatic mutations on MEN1 gene and no copy number variation or fusion events were detected. It is well-known that the mutation of MEN1 is the typical manifestation of MEN1 syndrome, which is an autosome dominant disease that includes varying combinations of more than 20 endocrine and non-endocrine tumors. In the English literature, 7 cases of solitary thymic carcinoid harboring somatic variants in MEN1 are reported in the absence of other organs involvement as MEN1 syndrome presents. We summarized the clinical features and prognosis of this rare thymic tumor.

[T-peptide Enhances the Killing Effects of Cisplatinum on Lung Cancer].

BACKGROUND: T peptide is extensively used in anti-tumor treatment. The aims of this study were to investigate whether T peptide enhances cisplatinum efficiency while reducing its side effects and to identify its effective mechanisms. METHODS: (1) Human macrophage U937 cells were treated with T peptide and/or cisplatinum. The levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) of each group were detected by enzyme-linked immunosorbent assay (ELISA); (2) Xenograft mouse models of human lung cancer were treated with T peptide and/or cisplatinum once every five days for three times. Tumor volumes were measured during treatment; (3) The percentages of macrophages in the peripheral blood of the xenograft mouse models were measured by FACS. RESULTS: (1) Compared with other groups, the level of TNF-α was significantly higher in the human macrophage U937 cells that were treated with T peptide combined with cisplatinum. The levels of IFN-γ were significantly higher in human macrophage U937 cells that were treated with T peptide alone or T peptide combined with cisplatinum; (2) In the xenograft mouse models, T peptide combined with cisplatinum treatment significantly inhibited tumor growth without weight loss compared with the other groups; (3) The percentages of macrophages in the peripheral blood were significantly higher in the xenograft mouse models that were treated with T peptide combined with cisplatinum compared with in the other groups. CONCLUSIONS: T peptide promotes macrophage proliferation and increases tumor cell killing factors (TNF-α, IFN-γ) in vitro. Moreover, T peptide enhances the efficacy of cisplatin and reduces its toxicity in vivo.
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[Expression and Clinical Significance of PD-1 and PD-L1 in Pulmonary Carcinoids].

BACKGROUND: The incidence of pulmonary carcinoid (PC) is very rare in primary lung malignant tumors, and the prognosis of this disease is closely associated with its pathological features. In this study, the expressions of programmed death 1 (PD-1) and programmed death ligand-1 (PD-L1) in lung carcinoid cells were detected, and the correlation between the expression and corresponding clinical physiological and pathologic features was further analyzed. METHODS: The expressions of PD-1 and PD-L1 in 20 cases of PC paraffin-embedded tissue specimens were detected through immunohistochemistry. The H-score of immunohistochemical staining (range, 0-300) was employed to evaluate the expression of PD-1 and PD-L1 in the tumor tissues. RESULTS: In the 20 cases of patients with PC, 40% (8/20) showed positive expressions of PD-1, and 45% (9/20) showed positive expressions of PD-L1. Significantly higher expressions of PD-1 were observed in the smoking patients than in the nonsmoking patients (63.64% vs 11.11%, P<0.05). Furthermore, no significant relationship was found between the expressions of PD-1 and PD-L1 and the clinical characteristics of the patients, such as age, gender, pathological type, clinical stage, and metastasis (P>0.05). CONCLUSIONS: Approximately 40% of PC patients had positive expressions of PD-1or PD-L1. The positive expression rate of PD-1 in the smoking patients was significantly higher than that in the nonsmoking patients. These results suggest that the expressions of PD-1 and PD-L1 may be associated with the occurrence and development of PC.