The immune microenvironments of lung and intraocular tumors

An increasing body of evidence underlines the prominent role of the immune microenvironment in cancer growth, invasion and metastasis. The local immune responses are specialized in the different organs. We will discuss the composition of the immune microenvironments and their role on tumor development in two cancers developing in opposite contexts: in the lung, which is at the interface of the outside world and in the eye, which is, an immunoprivileged site protected from it. We demonstrate that the immune system plays a major role in control of tumors, despite of these highly different tissue microenvironments.     

The microenvironments of multistage carcinogenesis

Overt neoplasia is often the result of a chronic disease process encompassing an extended segment of the lifespan of any species. A common pathway in the natural history of the disease is the appearance of focal proliferative lesions that are known to act as precursors for cancer development. It is becoming increasingly apparent that the emergence of such lesions is not a cell-autonomous phenomenon, but is heavily dependent on microenvironmental cues derived from the surrounding tissue. Specific alterations in the tissue microenvironment that can foster the selective growth of focal lesions are discussed herein. Furthermore, we argue that a fundamental property of focal lesions as it relates to their precancerous nature lies in their altered growth pattern as compared to the tissue where they reside. The resulting altered tissue architecture translates into the emergence of a unique tumor microenvironment inside these lesions, associated with altered blood vessels and/or blood supply which in turn can trigger biochemical and metabolic changes fueling tumor progression. A deeper understanding of the role(s) of tissue and tumor microenvironments in the pathogenesis of cancer is essential to design more effective strategies for the management of this disease.     

Yin and yang of tumor inflammation: How innate immune suppressors shape the tumor microenvironments

Pattern recognition‐mediated sensing systems direct host immunity towards either antitumor immunosurveillance or protumorigenic inflammation. These activities imply dual and conflicting roles in the regulation of tumor‐associated inflammation. On the one hand, recent evidence has revealed that several signaling components and cell‐surface receptors suppress innate immune signals and constitute a negative feedback machinery preventing excess and continuous inflammation within tumor microenvironments. On the other hand, these same components also negatively regulate intrinsic tumorigenic activities by targeting nuclear factor‐kappaB (NF‐κB)‐mediated antiapoptotic and inflammatory signals. Furthermore, the activation status of innate immune suppressors may reflect the functional plasticity of interactions between tumor cells and innate immune cells and determine whether tumor inflammation supports anti‐ or pro‐tumorigenic responses. Thus, innate immune suppressors may provide valuable information about the immunogenic or tumorigenic status of tumor‐associated inflammation thereby serving as potential biomarkers that predict tumor progression. Comprehensive analysis for identifying general and unique features of each innate immune suppressor in the regulation of tumor inflammation should explore the development of new biomarkers for improving future therapeutic strategies.     

Prognostic value of extracapsular invasion and fibrotic focus in single lymph node metastasis of gastric cancer

BACKGROUND: Histological findings of metastatic lymph nodes are important prognosticators in patients with gastric cancer. The aim of this study was to clarify the clinical significance of various pathological characteristics of the early phase of lymph node metastasis in patients with gastric cancer, by selecting patients with tumors that had single lymph node metastases, no serosal invasion, and no metastases to the peritoneum, liver, or distant organs. METHODS: Seventy-eight patients were eligible and were entered in this study. These patients were subdivided according to the following histological characteristics of the one metastatic lymph node: size of the metastasis (i.e., amount of tumor cells [AT]), proliferating pattern (PP), intranodal location (IL), and the presence or absence of extracapsular invasion (ECI) and/or fibrotic focus (FF). Associations between clinicopathological factors, survival, and the nodal findings were examined. RESULTS: There were no correlations between AT or PP and any clinicopathological factors. IL was significantly correlated with venous invasion and the pathological characteristics of the primary tumor. ECI and FF were observed significantly more frequently in pT2 than in pT1 cancer. Overall survival (OS) differed significantly according to depth of invasion, venous invasion, and the presence or absence of ECI or FF, although OS was not affected by AT, PP, or IL. The 10-year overall survival rates of patients with and without ECI were 50% and 80%, respectively, while these rates for patients with and without FF were 50% and 79%, respectively. Multivariate analysis revealed that ECI and FF were significant prognosticators of survival. CONCLUSION: These results strongly suggested that the presence of ECI or FF could affect the survival of patients with gastric cancer.     

The cyan fluorescent protein nude mouse as a host for multicolor-coded imaging models of primary and metastatic tumor microenvironments

The tumor microenvironment (TME) has an important influence on tumor progression. For example, we have discovered that passenger stromal cells are necessary for metastasis. In this report, we describe six different cyan fluorescent protein (CFP) multicolor TME nude mouse models. The six different implantation models were used to image the TME using multiple colors of fluorescent proteins: I) Red fluorescent protein (RFP)- or green fluorescent protein (GFP)-expressing HCT-116 human colon cancer cells were implanted subcutaneously in the CFP-expressing nude mice. CFP stromal elements from the subcutaneous TME were visualized interacting with the RFP- or GFP-expressing tumors. II) RFP-expressing HCT-116 cells were transplanted into the spleen of CFP nude mice, and experimental metastases were then formed in the liver. CFP stromal elements from the liver TME were visualized interacting with the RFP-expressing tumor. III) RFP-expressing HCT-116 cancer cells were transplanted in the tail vein of CFP-expressing nude mice, forming experimental metastases in the lung. CFP stromal elements from the lung were visualized interacting with the RFP-expressing tumor. IV) In order to visualize two different tumors in the TME, GFP-expressing and RFP-expressing HCT-116 cancer cells were co-implanted subcutaneously in CFP-expressing nude mice. A 3-color TME was formed subcutaneously in the CFP mouse, and CFP stromal elements were visualized interacting with the RFP- and GFP-expressing tumors. V) In order to have two different colors of stromal elements, GFP-expressing HCT-116 cells were initially injected subcutaneously in RFP-expressing nude mice. After 14 days, the tumor, which consisted of GFP cancer cells and RFP stromal cells derived from the RFP nude mouse, was harvested and transplanted into the CFP nude mouse. CFP stromal cells invaded the growing transplanted tumor containing GFP cancer cells and RFP stroma. VI) Mouse mammary tumor (MMT) cells expressing GFP in the nucleus and RFP in the cytoplasm were implanted in the spleen of a CFP nude mouse. Cancer cells were imaged in the liver 3 days after cell injection. The dual-color dividing MMT cells and CFP hepatocytes, as well as CFP non-parenchymal cells of the liver were imaged interacting with the 2-color cancer cells. CFP-expressing host cancer-associated fibroblasts (CAFs) were predominantly observed in the TME models developed in the CFP nude mouse. Thus, the CFP nude mouse adds another color to the pallet of the TME, allowing multiple types of color-coded cancer and stromal cells to be imaged simultaneously. The multi-colored models described in this report provide new opportunities to study the cellular interactions in the live primary and metastatic TME.     

新型驱动基因融合阳性非小细胞肺癌脑转移的研究进展北大核心

肺癌是我国最常见且死亡率最高的恶性肿瘤之一,随着表皮生长因子受体(EGFR)、间变性淋巴瘤激酶(ALK)及活性氧1(ROS1)等驱动基因及其相应分子靶向药物的出现,晚期非小细胞肺癌的治疗和预后发生了革命性变化。此外,一些少见新型驱动基因融合,包括神经调节蛋白1(NRG1)、神经营养酪氨酸受体激酶(NTRK)和转染重排因子(RET),正逐渐发展成为全身性治疗选择。然而,这些罕见新型融合驱动基因在NSCLC脑转移中的作用机制,以及优化控制和预防脑转移的意义人们所知甚少。因此,本文就近几年罕见驱动基因融合在NSCLC脑转移中的研究进行综述。     

The non-coding transcriptome as a dynamic regulator of cancer metastasis

Since the discovery of microRNAs, non-coding RNAs (NC-RNAs) have increasingly attracted the attention of cancer investigators. Two classes of NC-RNAs are emerging as putative metastasis-related genes: long non-coding RNAs (lncRNAs) and small nucleolar RNAs (snoRNAs). LncRNAs orchestrate metastatic progression through several mechanisms, including the interaction with epigenetic effectors, splicing control and generation of microRNA-like molecules. In contrast, snoRNAs have been long considered “housekeeping” genes with no relevant function in cancer. However, recent evidence challenges this assumption, indicating that some snoRNAs are deregulated in cancer cells and may play a specific role in metastasis. Interestingly, snoRNAs and lncRNAs share several mechanisms of action, and might synergize with protein-coding genes to generate a specific cellular phenotype. This evidence suggests that the current paradigm of metastatic progression is incomplete. We propose that NC-RNAs are organized in complex interactive networks which orchestrate cellular phenotypic plasticity. Since plasticity is critical for cancer cell metastasis, we suggest that a molecular interactome composed by both NC-RNAs and proteins orchestrates cancer metastasis. Interestingly, expression of lncRNAs and snoRNAs can be detected in biological fluids, making them potentially useful biomarkers. NC-RNA expression profiles in human neoplasms have been associated with patients’ prognosis. SnoRNA and lncRNA silencing in pre-clinical models leads to cancer cell death and/or metastasis prevention, suggesting they can be investigated as novel therapeutic targets. Based on the literature to date, we critically discuss how the NC-RNA interactome can be explored and manipulated to generate more effective diagnostic, prognostic, and therapeutic strategies for metastatic neoplasms.     

Role of apoptosis resistance in immune evasion and metastasis of colorectal cancer

The host immune system functions as a guardian against tumor development. It has been demonstrated that cytotoxic T lymphocyte (CTL)-mediated cytotoxic pathways function to inhibit or delay human colorectal cancer development. However, the host anti-tumor immune responses also 'edit' the tumor and select for more aggressive variants, resulting in immune evasion and tumor escape. Fas is a death receptor that mediates one of the major cytotoxic effector mechanisms of the CTLs. Fas is highly expressed in normal human colon epithelial cells but is frequently silenced in colorectal carcinoma, especially in metastatic colorectal carcinoma, suggesting that loss of Fas expression and function may be an immune evasion and tumor escape mechanism. In addition, recent studies indicated that Fas also mediates cellular proliferation signaling pathways to promote tumor development. Therefore, the death receptor Fas may not only transduce death signals to suppress tumor development but also activate cellular proliferation and the migration process to promote tumor growth and progression. Thus, understanding the mechanisms by which the Fas receptor and its associated protein complex transduces the death and survival signals may identify molecular targets for the development of therapeutic strategy to enhance the Fas-mediated death signals to increase the efficacy of cancer immunotherapy.     

Reorganization of thymic microenvironments during development and lymphomagenesis

Modulation of thymic microenvironments during ontogeny and lymphomagenesis in mice was studied with two rat monoclonal antibodies (moAb) which recognized distinct subpopulations of thymic epithelial reticular cells (TER). In adult thymus, the TER subpopulation stained by moAb B6TS-1 was localized in the subcapsular zone, cortico-medullary junction, and medulla. In fetal thymus, it was initially distributed throughout the rudiment, but after day 16 of gestation, it was rapidly redistributed to the locations seen in adult thymus. From an early stage of thymic lymphomagenesis, the TER bearing mB6TS-1 (epitope defined by moAb B6TS-1) in the cortico-medullary junction, in particular those associating with small blood vessels, proliferated and formed a characteristic network throughout the thymus, in which numerous growing lymphoma cells were entrapped. On the other hand, moAb AKTS-1 stained another TER subpopulation that was localized in the cortex in both fetal and adult thymus. Unlike mB6TS-1+ TER, mAKTS-1+ TER became increasingly sparser during lymphomagenesis. Selective proliferation of the mB6TS-1+ TER subpopulation in the cortico-medullary junction was seen in spontaneous, radiation-induced, and chemical-induced mouse thymic lymphomas. The possible biological significance of such modulation of thymic microenvironments in the natural history of lymphomagenesis is discussed.     

The effect of the immune status of the TAR mouse on the growth and metastasis of tumour xenografts

Mice thymectomised at 3–4 weeks of age and subsequently given whole-body irradiation (9 Gy) under cytosine arabinoside cover (TAR mice) provide an alternative model to the athymic nude (nu+/nu+) mouse for studying the biological characteristics of tumour xenografts. In the present study we have evaluated the repopulation events in the bone marrow and spleen following whole body irradiation of TAR mice, and analysed immune competence up to 98 days following irradiation. Repopulation of both bone marrow and spleen was evident in the weeks following whole body irradiation, and an initial increase in the relative proportion of T-lymphocytes present in the spleen was followed by a decrease in the percentage of lymphocytes expressing T-cell markers, which remained below the level observed in control mouse spleen cell preparations. TAR mice exhibited a decreased ability to respond to a non-specific T-cell mitogen and to elicit a T-cell dependent antibody response to influenza viral antigen. Both TAR and control mice possessed macrophages which could be activated to the tumouricidal state, and natural killer activity of TAR mice was enhanced greater than 3-fold above control values. The ability of TAR mice to accept tumor xenografts decreased with the increasing time interval between irradiation and subcutaneous implantation of tumour cells, and (in some instances) spontaneous regression was observed. In addition, a hamster tumour cell line possessing high metastatic potential in its syngeneic host was shown to metastasise to the regional lymph node, lungs, liver, kidneys and spleen of TAR mice from a cell inoculum implanted subcutaneously immediately after irradiation; however, with increasing time between irradiation and inoculation of tumour cells tumour metastasis decreased. The ability of TAR mice to support the growth and metastasis of tumour xenografts would appear to inversely correlate with the increase in natural killer cell activity following irradiation.     

氩氦冷冻联合非甲基化CpG-ODN对兔肝癌模型的抗肿瘤效应

目的探讨氩氦冷冻治疗对肝癌转移的影响及继发免疫效应的抗肿瘤效果。方法兔VX2肝肿瘤模型54只,30只随机分为A、B和C组,每组10只,分别给予氩氦冷冻、手术切除和假手术(对照组),观察肿瘤转移和生存期;另外24只,随机分成D、E和F组,每组8只,分别给予氩氦冷冻 CpG-ODN、氩氦冷冻和手术治疗,治疗后2周在兔大腿肌肉接种VX2瘤组织。结果A组肝内转移率低于C组(P=0.003),A组肺转移时间比C组推迟;A组和B组相比,不促进肿瘤转移。再接种VX2瘤组织2周后D、E和F组瘤重分别为(0.425±0.327)g(n=6)、(0.704±0.325)g(n=8)和(1.119±0.261)g(n=7),D组与F组瘤重差异有显著性(P=0.003)。结论氩氦冷冻治疗肝肿瘤不促进转移,CpG-ODN能增强氩氦冷冻治疗后的抗肿瘤效果。     

低剂量电离辐射对小鼠肿瘤转移及免疫功能的影响

 C₅₇BL/6,小鼠眼静脉注射B16黑色素瘤细胞24小时后，进行75mGyX线全身一次照射，结果显示，照射后小鼠的肺转移结节数明显低于对照组。机体免疫功能比对照组明显增强。     

Identification of CD146 as a marker enriched for tumor-propagating capacity reveals targetable pathways in primary human sarcoma

Tumor-propagating cells (TPCs) are believed to drive cancer initiation, progression and recurrence. These cells are characterized by enhanced tumorigenicity and self-renewal. The ability to identify such cells in primary human sarcomas relies on the dye exclusion ability of tumor side population (SP) cells. Here, we performed a high-throughput cell surface antigen screen and found that CD146 is enriched in the SP population. In vivo serial transplantation assays showed that CD146⁺ cells are highly tumorigenic, capable of self-renewal and thus enriches for the TPC population. In addition, depletion of SP cells from the CD146⁺ population show that CD146⁺ cells and SP cells are a distinct and overlapping TPC populations. Gene expression profiling of CD146⁺ and SP cells revealed multiple pathways commonly upregulated in both of these populations. Inhibition of one of these upregulated pathways, Notch signaling, significantly reduced tumor growth and self-renewal. Our data demonstrate that CD146 is an effective cell surface marker for enriching TPCs in primary human sarcomas. Targeting differentially activated pathways in TPCs may provide new therapeutic strategies for treating sarcoma.     

CD20阳性细胞与胃癌浸润转移关系初探

目的探讨CD20阳性细胞与胃癌浸润转移的关系。方法免疫组化S—P法检测78例胃癌组织CD20阳性细胞浸润与MMP-2和VEGF表达情况，分析CD20阳性细胞浸润与胃癌临床病理特点及MMP-2和VEGF表达的关系。结果有淋巴结转移及浸润程度越深的胃癌组织CD20阳性细胞浸润越多，同时CD20阳性细胞浸润数目与MMP-2和VEGF的表达强度成正相关。结论CD20阳性细胞与胃癌浸润转移密切相关。     

The combined use of steroids and immune checkpoint inhibitors in brain metastasis patients: a systematic review and meta-analysis

BackgroundImmune checkpoint inhibitors (ICI) have been a breakthrough for selected cancer patients, including those with brain metastases (BMs). Likewise, steroids have been an integral component of symptomatic management of BM patients. However, clinical evidence on the interaction between ICI and steroids in BM patients is conflicting and has not adequately been summarized thus far. Hence, the aim of this study was to perform a systematic literature review and meta-analysis on the association between steroid use and overall survival (OS) in BM patients receiving ICI.MethodsA systematic literature search was performed. Pooled effect estimates were calculated using random-effects models across included studies.ResultsAfter screening 1145 abstracts, 15 observational studies were included. Fourteen studies reported sufficient data for meta-analysis, comprising 1102 BM patients of which 32.1% received steroids. In the steroid group, median OS ranged from 2.9 to 10.2 months. In the nonsteroid group, median OS ranged from 4.9 to 25.1 months. Pooled results demonstrated significantly worse OS (HR = 1.84, 95% CI 1.22-2.77) and systemic progression-free survival (PFS; HR = 2.00, 95% CI 1.37-2.91) in the steroid group. Stratified analysis showed a consistent effect across the melanoma subgroup; not in the lung cancer subgroup. No significant association was shown between steroid use and intracranial PFS (HR = 1.31, 95% CI 0.42-4.07).ConclusionsAdministration of steroids was associated with significantly worse OS and PFS in BM patients receiving ICI. Further research on dose, timing, and duration of steroids is needed to elucidate the cause of this association and optimize outcomes in BM patients receiving ICI.     

The mutational spectrum of squamous-cell carcinoma of the head and neck: targetable genetic events and clinical impact

Squamous-cell cancer of the head and neck (SCCHN) represents a heterogeneous disease entity, with various etiological factors implicated in the genesis of distinct molecular subsets of tumors, which exhibit different biological and clinical behavior. Treatment of SCCHN is expected to change in the next decade as targeted therapies continue to make strides. Recently, next-generation sequencing studies conducted on ∼190 SCCHN specimens shed light into the molecular pathogenesis of the disease. These studies discovered mutations in genes involved in the differentiation program of squamous epithelium and the Notch/p63 axis (such as NOTCH1, TP63 and FBXW7), and validated genetic alterations derived from previous studies (such as mutations in TP53, CDKN2A, PIK3CA, CCND1 and HRAS) as driver genetic events in SCCHN neoplastic transformation. More recently, comprehensive data from The Cancer Genome Atlas (TCGA) project on 306 SCCHN specimens provided further insight into SCCHN inherent molecular complexity, identifying novel significantly mutated genes, including FAT1, MLL2, TGFRBR2, HLA-A, NFE2l2 and CASP8. In this article, we provide an overview of the mutational spectrum of SCCHN, with emphasis on the clinical implementation of this knowledge. We also discuss the potential integration of new data within the framework of precision cancer medicine.     

Treatment and outcome of brain metastasis as first site of distant metastasis from breast cancer

Twenty-eight consecutive patients with breast cancer were analyzedwho presented with a single brain metastasis asfirst site of distant metastasis. The response tosurgery with postoperative radiation therapy (RT) (9 patients)and to non-surgical therapy as first-line treatment was100% and 89% respectively with a significant differencein median recurrence-free intervals of 23 months andof 5 months respectively (p=0.033). Retreatmentof a local relapse by surgery (± RT,± chemotherapy) or by non-surgical treatment resulted ina response in 6 of the 7 operatedpatients and in 5 of the 6 non-operatedpatients with a median duration of response of7 months (range 2–20 months) and of 3months (range 2–4 months) respectively. The overall mediansurvival of the 28 patients with a singlebrain metastasis was 16 months (range 2–39 months).The median survival in the primarily operated patientswas 23 months, in the primarily not-operated group10 months, and in the never-operated group 9months. In comparison, the response to non-surgical treatmentin 20 consecutive patients who presented with multiplebrain metastases as first site of distant metastasiswas 55% with a median recurrence free intervalof 4 months. The median survival in thisgroup was 4 months, which was significantly shorterthan survival of patients with single brain metastasis(p=0.0036). These results suggest that breastcancer patients with a single brain metastasis asfirst presentation of relapse constitute a specific subgroupwith a favorable response to treatment and along survival especially if they can be treatedby surgery with postoperative RT.