微小RNA研究进展

微小RNA(miRNA)是参与基因转录后水平调控的非编码小分子RNA.人类基因中大约有3%编码miRNAs,而编码蛋白的基因中30%受到miRNAs的调控.miRNAs在多种生物进程中起到关键作用,包括调节发育、细胞增殖、分化和凋亡,相应的miRNAs的表达变化与包括肿瘤在内的多种疾病有关.本文综述miRNAs的生物学及其与肿瘤的联系,并讨论了miRNAs的研究方法.     

MicroRNAs在乳腺癌中作用的研究进展

MicroRNAs（miRNAs）是一类新发现的非编码RNA分子，通常在转录后水平调控基因表达，广泛参与细胞增殖、分化与凋亡等生命过程。据文献报道，有15种miRNAs位于人类乳腺癌相关断点区域。这表明，特定类型癌症中包括miRNAs在内的基因区域的缺失或获得都与恶性肿瘤的发生有关。miRNAs的表达变化及其对靶基因的综合调控对乳腺癌的发生发展、特殊肿瘤表型的形成及预后等产生深远的影响。     

同源重组修复相关miRNAs在肿瘤中的研究进展

同源重组（HR）作为DNA双链断裂损伤的主要修复机制,其功能异常可影响肿瘤对放疗及基因毒药物的敏感性并可为肿瘤个体化治疗提供生物标志物。微小核糖核酸（microRNAs,miRNAs）通过与mRNA的3' 端非编码区结合来实现对靶基因的转录后调控。近年来研究发现miRNAs对同源重组修复通路也发挥着重要的调控作用,并影响肿瘤对放疗及基因毒药物的敏感性。本文对肿瘤中miRNAs调控HR修复通路的新进展进行综述。     

MircoRNA-26a与肿瘤

微小RNA(microRNAs,miRNAs)是一类由20个-22个核苷酸组成的小片段非编码RNA,通过靶向结合基因mRNA的3'非翻译区(3'-UTR)调控其表达.许多研究报道miRNAs参与肿瘤的发生发展.MiR-26a在不同的肿瘤中发挥不同的作用,在肿瘤增殖、转移侵袭、血管形成、生物代谢及诊断预后中都有作用.本文就miR-26a与肿瘤关系的研究进展进行综述.     

EBV BART microRNAs 在鼻咽癌中的作用研究进展

摘 要：MicroRNAs(miRNAs)是一类长度大约22nt的内源性非编码单链RNA,在转录后水平调控基因的表达。EBV BART microRNAs是由EBV BART基因编码,其与鼻咽癌(nasopharyngeal carcinoma,NPC)的发生及发展有着重要的关系。目前研究发现BART miRNAs在NPC中的作用主要与免疫逃逸、侵袭转移及抗凋亡作用等相关。文章主要对EBV BART microRNAs 在NPC中的作用进行综述。     

miR-485-5p在恶性肿瘤中的研究进展

MicroRNAs(miRNAs)是一类长度约22个核苷酸的非编码RNA,在基因表达调控中,参与多种重要的生理和病理过程。miRNAs能够特异性结合靶基因序列,抑制基因的转录或翻译,从而抑制基因在转录或转录后水平上的表达。miRNAs作为肿瘤抑制因子或促进因子在癌症发生发展中经常失调。最近的研究发现miR-485-5p在多种癌症中表达下调,并调控肿瘤细胞生长、增殖、侵袭和迁移。miR-485-5p在肿瘤诊断、治疗及预后相关方面可作为具有潜在价值的肿瘤标志物,并有望成为临床肿瘤靶向治疗的新的治疗靶点。本文围绕miR-485-5p在肝癌、胃癌、乳腺癌及其他恶性肿瘤中的研究进展展开综述并对其未来应用和发展进行展望。     

miRNAs:肿瘤诊断治疗的潜在新型靶分子

MicroRNAs(miRNAs)是一类非编码调节基因表达的短链RNA分子,通过与靶基因3’非翻译区完全或不完全互补结合,降解靶基因或抑制靶基因的翻译,实现对靶基因表达的调节。miRNAs在肿瘤组织异常表达,与肿瘤发生、发展、转移等关系密切,成为近年来新型潜在的肿瘤标志物。通过检测血液miRNAs或对肿瘤组织异常表达的miRNAs进行显像,有利于对肿瘤进行早期诊断、预后评估及疗效监测等;以miR-NAs为靶点,可针对肿瘤开展靶向分子治疗。全面深入研究miRNAs的分子功能、分子影像及靶向治疗,有望为肿瘤的诊断和治疗带来新的思路和方法。     

肿瘤相关巨噬细胞与长链非编码RNA在肿瘤发展中的研究进展

肿瘤相关巨噬细胞是肿瘤微环境重要组成部分,极化亚型影响肿瘤进展过程。长链非编码RNA(long non-coding RNA,lncRNA)不编码蛋白质,但是同样参与生物学过程,异常表达的lncRNA影响生理和病理进程,尤其对肿瘤发展有重要调控作用。癌症中一些异常表达的lncRNA直接或者间接影响巨噬细胞极化亚型调控肿瘤发展进程,lncRNA和巨噬细胞之间调节机制尚未清楚。lncRNA同肿瘤相关巨噬细胞可作为肿瘤潜在靶点和治疗中间物。本文将对在肿瘤中相互作用的肿瘤相关巨噬细胞与长链非编码RNA调控肿瘤进展过程进行综述。      

基于单细胞测序分析肿瘤相关巨噬细胞来源的半乳糖凝集素3的功能

目的：从肿瘤相关巨噬细胞（TAM）在化疗前后的表型变化入手,寻找通过调控肿瘤免疫微环境（TIME）从而影响肿瘤治疗效果和预后的功能分子。方法：利用欧洲核苷酸数据库（ENA）的PRJEB45598数据集,分析进展期胃癌患者化疗前后活检肿瘤组织单细胞测序数据,采用主成分分析（PCA）和一致流形近似与投影（UMAP）降维,获得31个亚群细胞,并进一步进行TAM亚型分析、差异基因筛选,寻找化疗后M2型TAM中高表达的基因。通过黑色素瘤B16-F10细胞皮下移植瘤模型验证化疗前后特定基因m RNA和蛋白水平表达变化,并通过Incucyte体外分析该蛋白是否调控化疗药物诱导的肿瘤细胞死亡。结果：聚焦单细胞测序数据中M2型TAM的特征表达基因,发现半乳糖凝集素3(LGALS3)在胃癌化疗后m RNA水平显著升高（P<0.01）,在多种肿瘤中LGALS3高表达且与患者生存期呈负相关（P<0.05或P<0.01）。黑色素瘤B16-F10细胞移植瘤模型中,LGALS3在M2型TAM中高表达（P<0.01）,且奥沙利铂化疗后表达进一步升高（P<0.05）。体外对肿瘤细胞给予重组...     

miR-149与肿瘤关系的研究进展

miRNAs是一类长度约为20~25个核苷酸，参与基因调控表达的内源性非编码RNA。miR-149作为miRNAs的重要成员，在多种肿瘤中表达异常，其表达水平与肿瘤细胞增殖、转移、凋亡、耐药、患者的早期诊断及预后密切相关。因此，miR-149有望成为新一类抗肿瘤治疗的靶点。     

Glycolysis regulation in tumor-associated macrophages: Its role in tumor development and cancer treatment

Tumor-associated macrophages constitute the main cell population in the tumor microenvironment and play a crucial role in regulating the microenvironment composition. Emerging evidence has revealed that the metabolic profile determines the tumor-associated macrophage phenotype. Tumor-associated macrophage function is highly dependent on glucose metabolism, with glycolysis being the major metabolic pathway. Recent reports have demonstrated diversity in glucose flux of tumor-associated macrophages and complex substance communication with cancer cells. However, how the glucose flux in tumor-associated macrophages connects with glycolysis to influence tumor progression and the tumor microenvironment is still obscure. Moreover, while the development of single-cell sequencing technology allows a clearer and more accurate classification of tumor-associated macrophages, the metabolic profiles of tumor-associated macrophages from the perspective of single-cell omics has not been well summarized. Here, we review the current state of knowledge on glucose metabolism in tumor-associated macrophages and summarize the metabolic profiles of different tumor-associated macrophage subtypes from the perspective of single-cell omics. Additionally, we describe the current strategies targeting glycolysis in tumor-associated macrophages for cancer therapy.     

Relationship between B7-H4, regulatory T cells, and patient outcome in human ovarian carcinoma

B7-H4 is a recently identified B7 family member. We previously showed that ovarian tumor and associated macrophages expressed B7-H4; tumor B7-H4+ macrophages and CD4+CD25+FOXP3+ regulatory T cells (Treg cells) suppressed tumor-associated antigen-specific T-cell immunity. To determine the pathologic relationship between B7-H4, macrophages, and Treg cells in the tumor environment, in addition to Treg cell numbers, we quantified B7-H4 expression in the tumor and tumor-associated macrophages in 103 patients with ovarian carcinoma. We observed that the intensity of B7-H4 expression in macrophages was significantly correlated with Treg cell numbers in the tumor. Further, both Treg cells and macrophage B7-H4, but not tumor B7-H4, were negatively associated with patient outcome. Tumor Treg cells enabled macrophages to spontaneously produce interleukin (IL)-10 and IL-6. Tumor macrophages stimulated B7-H4 expression in an autocrine manner through IL-10 and IL-6. Our previous work showed that tumor-associated macrophages spontaneously produced chemokine CCL22 to mediate Treg cell trafficking into tumor, and Treg cells induced B7-H4 on antigen-presenting cells (APC) including macrophages. Altogether, our data support the concept that there is a mechanistic interaction between Treg cells and macrophage, and that Treg cells may convey the suppressive activity to APCs through B7-H4 induction in human ovarian cancer.     

Expression of cyclooxygenase-2 and inducible nitric oxide synthase in human ovarian tumors and tumor-associated macrophages

This study investigates whether and to what extent cyclooxygenase type-2 (COX-2) and inducible nitric oxide-synthase (iNOS), both known to have an immunosuppressive effect, are expressed in human ovarian tumors. Because COX-2 and iNOS can be expressed by activated macrophages, the presence of tumor-associated macrophages and the expression of COX-2 and iNOS by these tumor-associated macrophages were determined. The results obtained may provide insight into the function of COX-2 and iNOS expression by tumors. The expression of COX-2 and iNOS in tumor cells and macrophages was assessed in 18 malignant, 15 borderline, and 14 benign human ovarian tumors by immunohistochemical staining of frozen tissue sections. The intra- and peritumoral macrophages were stained using an anti-CD68 monoclonal antibody. Most of the malignant tumors (15 of 18), 10 of 15 borderline, and 9 of 14 benign tumors showed COX-2 expression in the epithelial cells, a result which indicates that COX-2 expression is not exclusive to malignancy. In addition, COX-2 staining was more intense in the epithelial cells of benign and borderline tumors than in malignant tumors. Weak iNOS staining was observed in 5 of 18 malignant, 4 of 15 borderline, and 5 of 14 benign tumors. The number of tumor-associated macrophages varied widely between the different tumors. The highest number of tumor-associated macrophages (> or =20/0.125 mm(2)) was observed in malignant tumors, whereas low to moderate intra- and peritumoral macrophage infiltration (5-20/0.125 mm(2)) was observed in the borderline and benign tumors. COX-2-positive tumor-associated macrophages were found in 3 of 18 malignant tumors, 7 of 15 borderline tumors, and 1 of 14 benign tumors. The number of COX-2-positive tumor-associated macrophages ranged from 3 to 30% of the total macrophage population. Some malignant (4 of 18), borderline (5 of 15), and benign (2 of 14) tumors contained iNOS-positive macrophages. Notable was that COX-2- and iNOS-positive macrophages were predominantly located in the tumor stroma, the regions between tumor and stroma, and in the lumina of the tumor when located in the tumor tissue. These data indicate that not only malignant but also borderline and benign ovarian tumors can exhibit increased levels of COX-2 and iNOS expression. In addition, a small proportion of the tumor-associated macrophages found in malignant, borderline, and benign tumors seems to be in an activated state, judged by their iNOS and COX-2 expression. This subpopulation of tumor-associated macrophages was invariably located in the tumor stroma or in the lumina of the tumor, specifically suggesting that macrophages outside the tumor can be tumor cytotoxic.     

Vascular endothelial growth factor receptor 2 mediates macrophage infiltration into orthotopic pancreatic tumors in mice

Macrophages are an abundant inflammatory cell type in the tumor microenvironment that can contribute to tumor growth and metastasis. Macrophage recruitment into tumors is mediated by multiple cytokines, including vascular endothelial growth factor (VEGF), which is thought to function primarily through VEGF receptor (VEGFR) 1 expressed on macrophages. Macrophage infiltration is affected by VEGF inhibition. We show that selective inhibition of VEGFR2 reduced macrophage infiltration into orthotopic pancreatic tumors. Our studies show that tumor-associated macrophages express VEGFR2. Furthermore, peritoneal macrophages from tumor-bearing animals express VEGFR2, whereas peritoneal macrophages from non-tumor-bearing animals do not. To our knowledge, this is the first time that tumor-associated macrophages have been shown to express VEGFR2. Additionally, we found that the cytokine pleiotrophin is sufficient to induce VEGFR2 expression on macrophages. Pleiotrophin has previously been shown to induce expression of endothelial cell markers on macrophages and was present in the microenvironment of orthotopic pancreatic tumors. Finally, we show that VEGFR2, when expressed by macrophages, is essential for VEGF-stimulated migration of tumor-associated macrophages. In summary, tumor-associated macrophages express VEGFR2, and selective inhibition of VEGFR2 reduces recruitment of macrophages into orthotopic pancreatic tumors. Our results show an underappreciated mechanism of action that may directly contribute to the antitumor activity of angiogenesis inhibitors that block the VEGFR2 pathway.     

Antagonist of phorbol ester receptor-mediated chemotaxis in mouse peritoneal macrophages

Biologically active phorbol ester derivatives displace [3H]phorbol-12, 13-dibutyrate from thioglycollate-elicited mouse peritoneal macrophages in a time-, temperature-, and concentration-dependent manner. Scatchard analysis revealed an apparent Kd of 54.1 nM and 8.0 X 10(5) sites/cell, indicating that these macrophages possess saturable, high-affinity phorbol ester-binding sites. These derivatives also act as chemoattractants for the macrophage at equivalent concentrations. A notable exception to this pattern is phorbol-12,13-diacetate. Phorbol-12,13-diacetate inhibits specific binding of [3H]phorbol-12,13-dibutyrate (concentration required for a 50% inhibition of the maximum specific binding of [3H]phorbol-12,13-dibutyrate, 2.6 microM) and chemotaxis to phorbol-12-myristate, 13-acetate (concentration required for a 50% inhibition of the maximum chemotactic response, 0.39 microM) while exhibiting no activity as a chemoattractant at concentrations up to 10(-5) M. The data indicate that phorbol-12,13-diacetate may be an antagonist for receptor-mediated chemotaxis to phorbol-12-myristate, 13-acetate in the macrophage.     

Chemotactic activity for mononuclear phagocytes of culture supernatants from murine and human tumor cells: Evidence for a role in the regulation of the macrophage content of neoplastic tissues

Culture supernatants from 14 mouse solid tumors, 2 mouse lymphomas, 8 human solid tumor lines and 3 human leukemia-lymphomas were examined for chemotactic activity in blind-well chemotaxis chambers using murine peritoneal macrophages and human blood monocytes as indicator cells. Culture supernatants from various murine and human solid tumors had appreciable chemotactic activity for mononuclear phagocytes. Chemotactic activity was found in murine tumors of different histology and transplantation history, including autochthonous mammary carcinomas and chemically-induced sarcomas. Chemotactic activity was not unique to neoplastic cells because is was detected also in supernatants of two preparations of mouse embryo fibroblasts and two human lung embryo fibroblast lines. Production of tumor-derived chemo-attractants did not require serum in the culture medium, was inhibited by the protein synthesis inhibitor Cycloheximide, but was unaffected by the DNA synthesis inhibitor Mitomycin C. Murine supernatants were active on human monocytes and vice-versa. A first preliminary characterization of the chemotactic activity of the human sarcoma line 8387 revealed that it was not dialyzable, that most of the activity was retained at 56deg;C for 30 min, but not at 100deg;C, and that it was susceptible to proteolytic enzymes (trypsin and proteinase K) but unaffected by DNase and RNase. Upon fractionation on a Sephadex G-75 column, the activity eluted in a single, relatively broad peak in the cytocrome C region, corresponding to an apparent molecular weight of about 12,000. In the heterogeneous series of murine solid tumors studied, a significant, though far from absolute, correlation (r=0.71, p=0.013) was found between chemotactic activity in culture supernatants (expressed as area under the chemotaxis titration curve) and the percentage of tumor-associated macrophages. It is suggested that tumor-derived chemotactic factor(s) play a role in the regulation of the macrophage content of neoplastic tissues.     

Inhibition of macrophage chemotaxis by neoplastic and other rapidly proliferating cells in vitro.

Culture supernatants from rapidly proliferating cell lines inhibit macrophage chemotaxis. Of the cell lines tested, the supernatant from polyoma virus-induced tumor cells was the strongest inhibitor, although supernatants from simian virus 40-transformed 3T3, dimethylbenzanthracene-induced tumor cells, and Chinease hamster ovary fibroblasts also possessed inhibitory activity. The inhibitory substance(s) bound onto the macrophage cell surface. Although none of the culture supernatants examined were chemotactic for rat macrophages, they did possess weak attractive activity for polymorphonuclear neutrophils. This capacity of rapidly growing cells in culture to generate substances inhibitory to macrophage chemotaxis while attracting polymorphonuclear neutrophils may be relevant to the mechanism by which tumor bearing in vivo produces a cell-specific defect in chronic but not acute inflammation.     

肿瘤相关巨噬细胞在胃癌中的作用

巨噬细胞广泛参与固有免疫及适应性免疫,其表型和功能具有很大可塑性,在不同微环境中巨噬细胞可分化为经典活化（M1表型）和替代活化（M2表型）,其中M2表型有免疫调节作用,参与诱导Th2反应。肿瘤微环境浸润的巨噬细胞即肿瘤相关巨噬细胞（TAMs）多具M2表型,能促进肿瘤新生血管生成、肿瘤侵袭和转移。由此可见,TAMs对胃癌的发生发展具有重要的免疫调节作用,本文就此进行综述。      

Homeobox A7 promotes esophageal squamous cell carcinoma progression through C-C motif chemokine ligand 2-mediated tumor-associated macrophage recruitment

Homeobox A7 (HOXA7) plays essential roles in multiple malignancies and was reported to be overexpressed in esophageal squamous cell carcinoma (ESCC). However, its functions in the ESCC tumor microenvironment remain to be explored. In this study, we showed that HOXA7 was overexpressed in ESCC among HOXA family members and correlated with tumor-associated macrophage (TAM) infiltration both in The Cancer Genome Atlas database and ESCC clinical samples. Moreover, transactivation of C-C motif chemokine ligand 2 (CCL2) by HOXA7 was identified (real-time quantitative PCR [RT-qPCR], western blot analysis, ELISA, and ChIP-qPCR), which was detected to drive chemotaxis and M2 polarization of macrophages both in vitro (Transwell assay) and in vivo (xenograft tumors models). In addition, CCL2 triggers macrophage expression of epidermal growth factor (EGF) (RT-qPCR and ELISA), which promotes tumor proliferation and metastasis by activating its receptor EGFR. In addition, EGF-induced ESCC cell proliferation and migration can be abrogated by HOXA7 knockdown (CCK-8 proliferation assay, EdU fluorescence, and Transwell assay). These results indicate a novel mechanistic role of HOXA7 in the cross-talk between ESCC and TAMs, which could be an underlying therapeutic target for ESCC.