T cells in pancreatic cancer stroma

Pancreatic ductal adenocarcinoma(PDAC)is a highly devastating disease with a dismal 5-year survival rate.PDAC has a complex tumour microenvironment;characterised by a robust desmoplastic stroma,extensive infiltration of immunesuppressive cells such as immature myeloid cells,tumour-associated macrophages,neutrophils and regulatory T cells,and the presence of exhausted and senescent T cells.The cross-talk between cells in this fibrotic tumour establishes an immune-privileged microenvironment that supports tumour cell escape from immune-surveillance,disease progression and spread to distant organs.PDAC tumours,considered to be non-immunogenic or cold,express low mutation burden,low infiltration of CD8+cytotoxic lymphocytes that are localised along the invasive margin of the tumour border in the surrounding fibrotic tissue,and often display an exhausted phenotype.Here,we review the role of T cells in pancreatic cancer,examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of T cells as therapy.

T cells in pancreatic cancer stroma:Tryptophan metabolism plays an important role in immunoregulation

Several studies have shown that the immune system is highly regulated by tryptophan metabolism,which serves as an immunomodulatory factor.The indoleamine 2,3-dioxygenase 1(IDO1),as an intracellular enzyme that participates in metabolism of the essential amino acid tryptophan in the kynurenine pathway,is an independent prognostic marker for pancreatic cancer(PC).First,overexpression of IDO1 inhibits the maturation of dendritic cells and T-cell proliferation in the liver and spleen.Second,the high expression of kynurenine induces and activates the aryl hydrocarbon receptor,resulting in upregulated programmed cell death protein 1 expression.Third,the induction of IDO1 can lead to loss of the T helper 17 cell/regulatory T cell balance,mediated by the proximal tryptophan catabolite from IDO metabolism.In our study,we found that overexpression of IDO1 upregulated CD8+T cells and reduced natural killer T cells in pancreatic carcinoma in mice.Hence,it may be essential to pay more attention to tryptophan metabolism in patients,especially those who are tolerant to immunotherapy for PC.

Natural killer cells in pancreatic cancer stroma

Pancreatic cancer remains one of medicine’s largest areas of unmet need.With five-year survival rates of<8%,little improvement has been made in the last 50 years.Typically presenting with advance stage disease,treatment options are limited.To date,surgery remains the only potentially curative option,however,with such late disease presentation,the majority of patients are unresectable.Thus,new therapeutic options and a greater understanding of the complex stromal interactions within the tumour microenvironment are sorely needed to revise the dismal outlook for pancreatic cancer patients.Natural killer(NK)cells are crucial effector units in cancer immunosurveillance.Often used as a prognostic biomarker in a range of malignancies,NK cells have received much attention as an attractive target for immunotherapies,both as cell therapy and as a pharmaceutical target.Despite this interest,the role of NK cells in pancreatic cancer remains poorly defined.Nevertheless,increasing evidence of the importance of NK cells in this dismal prognosis disease is beginning to come to light.Here,we review the role of NK cells in pancreatic cancer,examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of NK cells as therapy.

Tumor–stromal cross-talk modulating the therapeutic response in pancreatic cancer

Background: Pancreatic ductal adenocarcinoma(PDAC) is a highly malignant solid tumor with a dismal prognosis. The stroma component makes up to 90% of the tumor mass and is thought to be one of the main reasons for the tumor’s high chemoresistance. Cancer associated fibroblasts(CAFs) have previously been identified to be the key stromal players. This is the first time we provide detailed in vitro experiments investigating tumor–stromal interactions when exposed to three well-known chemotherapeutic agents. Methods: Monocultures, indirect and direct co-cultures of two PDAC cell lines(AsPC and Panc-1) and six primary patients derived CAFs were treated with gemcitabine, nab-paclitaxel and the γ-secretaseinhibitor(GSI) DAPT. The cell viability of each component was measured with XTT. Finally, IL-6 concentrations of the supernatants were analyzed. Results: On the contrary to PDAC cell lines, CAF monocultures hardly responded to any treatment which suggested that stroma(CAFs) itself is more resistant to standard chemo-treatments than the epithelial cancer cells. Moreover, only a weak chemotherapeutic response was observed in direct co-cultures of cancer cells with CAFs. A change in the morphology of direct co-cultures was accompanied with the chemoresistance. CAFs were observed to build cage-like structures around agglomerates of tumor cells. High levels of IL-6 were also associated with a reduced response to therapy. Indirect co-cultures make the tumor–stromal interaction more complex. Conclusions: CAFs are highly chemoresistant. Direct cell–cell contact and high levels of IL-6 correlate with a high chemoresistance.

Shattering the castle walls: Anti-stromal therapy for pancreatic cancer

Despite the availability of potent chemotherapy regimens, such as 5-fluorouracil, folinic acid, irinotecan, and oxaliplatin(FOLFIRINOX) and nab-paclitaxel plus gemcitabine, treatment outcomes in metastatic pancreatic cancer(PC) remain unsatisfactory. The presence of an abundant fibrous stroma in PC is considered a crucial factor for its unfavorable condition. Apparently, stroma acts as a physical barrier to restrict intratumoral cytotoxic drug penetration and creates a hypoxic environment that reduces the efficacy of radiotherapy. In addition, stroma plays a vital supportive role in the development and progression of PC, which has prompted researchers to assess the potential benefits of agents targeting several cellular(e.g., stellate cells) and acellular(e.g., hyaluronan) elements of the stroma. This study aims to briefly review the primary structural properties of PC stroma and its interaction with cancer cells and summarize the current status of antistromal therapies in the management of metastatic PC.

Pancreatic cancer and its stroma: A conspiracy theory

Pancreatic cancer is characterised by a prominent desmoplastic/stromal reaction that has received little attention until recent times. Given that treatments focusing on pancreatic cancer cells alone have failed to significantly improve patient outcome over many decades, research efforts have now moved to understanding the pathophysiology of the stromal reaction and its role in cancer progression. In this regard, our Group was the first to identify the cells(pancreatic stellate cells, PSCs) that produced the collagenous stroma of pancreatic cancer and to demonstrate that these cells interacted closely with cancer cells to facilitate local tumour growth and distant metastasis. Evidence is accumulating to indicate that stromal PSCs may also mediate angiogenesis, immune evasion and the well known resistance of pancreatic cancer to chemotherapy and radiotherapy. This review will summarise current knowledge regarding the critical role of pancreatic stellate cells and the stroma in pancreatic cancer biologyand the therapeutic approaches being developed to target the stroma in a bid to improve the outcome of this devastating disease.

Loss of stromal caveolin-1 expression in colorectal cancer predicts poor survival

AIM: To investigate the clinicopathological significance and prognostic value of caveolin-1(CAV-1) in both tumor and stromal cells in colorectal cancer(CRC).METHODS: A total of 178 patients with CRC were included in this study. The correlation between CAV-1expression and clinicopathologic features and survival was studied.RESULTS: CAV-1 expression was detected in tumor and stromal cells. The expression of stromal CAV-1 was closely associated with histological type(P = 0.022), pathologic tumor-node-metastasis stage(P = 0.047), pathologic N stage(P = 0.035) and recurrence(P = 0.000). However, tumor cell CAV-1 did not show any correlation with clinical parameters. Additionally, the loss of stromal CAV-1 expression was associated with shorter disease-free survival(P = 0.000) and overall survival(P = 0.000). Multivariate analysis revealed that the loss of stromal CAV-1 expression was an independent prognostic factor for both overall survival(P = 0.014) and disease-free survival(P = 0.006).CONCLUSION: The loss of stromal CAV-1 expression in CRC was associated with poor prognosis and could be a prognostic factor for CRC patients.

Intensity of stromal changes is associated with tumor relapse in clinically advanced prostate cancer after castration therapy

Reactive stromal changes in prostate cancer （PCa） are likely involved in the emergence of castration-resistant PCa （CRPC）. This study was designed to investigate stromal changes in patients with clinically advanced PCa and analyze their prognostic significance. Prostate needle biopsies obtained from 148 patients before castration therapy were analyzed by Masson trichrome staining and immunohistochemical analysis of vimentin and desmin. Reactive stroma grading was inversely correlated with Gleason score. Stroma grade （Masson stain 82.8% vs 45.6%, P 〈 0.001） and vimentin expression （P = 0.005） were significantly higher, and desmin expression （P = 0.004） significantly lower, in reactive stroma of tumors with a Gleason score of 6-7 than in adjacent peritumoral tissue. Kaplan-Meier analysis showed a significant association between reactive stroma grade in tumors and the occurrence of CRPC in patients with a Gleason score of 6-7 （P= 0.009）. Furthermore, patients with higher vimentin or lower desmin expression had a shorter disease-free period. In multivariate analysis, only vimentin expression was a significant predictor of tumor relapse （hazard ratio 1.78, 95% confidence interval 1.12-10.26, P = 0.012）. These findings indicate that the intensity of reactive stroma is associated with castration responsiveness, especially in patients with a lower Gleason score where the abundant stroma component is most frequently found. High expression of vimentin in tumor stroma was independently associated with poor outcomes in patients with Gleason scores of 6-7, and may serve as a new prognostic marker in daily practice.

Potential synergistic implications for stromal-targeted radiopharmaceuticals in bone-metastatic prostate cancer

Genetic heterogeneity and chemotherapy-resistant ＇stem cells＇ represent two of the most pressing issues in devising new strategies for the treatment of advanced prostate cancer. Though curative strategies have long been present for men with localized disease, metastatic prostate cancer is currently incurable. Though substantial improvements in outcomes are now possible through the utilization of newly approved therapies, novel combinations are clearly needed. Herein we describe potentially synergistic interactions between bone stromal-targeted radiopharmaceuticals and other therapies for treatment of bone-metastatic prostate cancer. Radiation has long been known to synergize with cytotoxic chemotherapies and recent data also suggest the possibility of synergy when combining radiation and immune-based strategies. Combination therapies will be required to substantially improve survival for men with castrate-resistant metastatic prostate cancer and we hypothesize that bone-targeted radiopharmaceuticals will play an important role in this Drocess.

Therapeutic strategies for targeting the ovarian tumor stroma

Epithelial ovarian cancer is the most lethal type of gynecologic malignancy. Sixty percent of women who are diagnosed with ovarian cancer present with advancedstage disease that involves the peritoneal cavity and these patients have a 5-year survival rate of less than 30%. For more than two decades, tumor-debulking surgery followed by platinum-taxane combination chemotherapy has remained the conventional first-line treatment of ovarian cancer. Although the initial response rate is 70%-80%, most patients with advancedstage ovarian cancer eventually relapse and succumb to recurrent chemoresistant disease. A number of molecular aberrations that drive tumor progression have been identified in ovarian cancer cells and intensive efforts have focused on developing therapeutic agents that target these aberrations. However, increasing evidence indicates that reciprocal interactions between tumor cells and various types of stromal cells also play important roles in driving ovarian tumor progression and that these stromal cells represent attractive therapeutic targets. Unlike tumor cells, stromal cells within the tumor microenvironment are in general geneticallystable and are therefore less likely to become resistant to therapy. This concise review discusses the biological significance of the cross-talk between ovarian cancer cells and three major types of stromal cells(endothelial cells, fibroblasts, macrophages) and the development of new-generation therapies that target the ovarian tumor microenvironment.

Targeting inflammation in pancreatic cancer: Clinical translation

Preclinical modelling studies are beginning to aid development of therapies targeted against key regulators of pancreatic cancer progression. Pancreatic cancer is an aggressive, stromally-rich tumor, from which few people survive. Within the tumor microenvironment cellular and extracellular components exist, shielding tumor cells from immune cell clearance, and chemotherapy, enhancing progression of the disease. The cellular component of this microenvironment consists mainly of stellate cells and inflammatory cells. New findings suggest that manipulation of the cellular component of the tumor microenvironment is possible to promote immune cell killing of tumor cells. Here we explore possible immunogenic therapeutic strategies. Additionally extracellular stromal elements play a key role in protecting tumor cells from chemotherapies targeted at the pancreas. We describe the experimental findings and the pitfalls associated with translation of stromally targeted therapies to clinical trial. Finally, we discuss the key inflammatory signal transducers activated subsequent to driver mutations in oncogenic Kras in pancreatic cancer. We present the preclinical findings that have led to successful early trials of STAT3 inhibitors in pancreatic adenocarcinoma.

Molecular mechanisms of metastasis in prostate cancer

Prostate cancer （PCa） preferentially metastasizes to the bone marrow stroma of the axial skeleton. This activity is the principal cause of PCa morbidity and mortality. The exact mechanism of PCa metastasis is currently unknown, although considerable progress has been made in determining the key players in this process. In this review, we present the current understanding of the molecular processes driving PCa metastasis to the bone.

Microenvironment and endocrine resistance in breast cancer:Friend or foe?

Breast cancer affects one in eight women around the world. Seventy five percent of these patients have tumors that are estrogen receptor positive and as a consequence receive endocrine therapy. However,about one third eventually develop resistance and cancer reappears. In the last decade our vision of cancer has evolved to consider it more of a tissuerelated disease than a cell-centered one. This editorial argues that we are only starting to understand the role the tumor microenvironment plays in therapy resistance in breast cancer. The development of new therapeutic strategies that target the microenvironment will come when we clearly understand this extremely complicated scenario. As such,and as a scientific community,we have extremely challenging work ahead. We share our views regarding these matters.

The diverse and contrasting effects of using human prostate cancer cell lines to study androgen receptor roles in prostate cancer

The androgen receptor （AR） plays an important role in the development and progression of prostate cancer （PCa）. Androgen deprivation therapy is initially effective in blocking tumor growth, but it eventually leads to the hormonerefractory state. The detailed mechanisms of the conversion from androgen dependence to androgen independence remain unclear. Several PCa cell lines were established to study the role of AR in PCa, but the results were often inconsistent or contrasting in different cell lines, or in the same cell line grown under different conditions. The cellular and molecular alteration of epithelial cells and their microenvironments are complicated, and it is difficult to use a single cell line to address this important issue and also to study the pathophysiological effects of AR. In this paper, we summarize the different effects of AR on multiple cell lines and show the disadvantages of using a single human PCa cell line to study AR effects on PCa. We also discuss the advantages of widely used epithelium-stroma co-culture systems, xenograft mouse models, and genetically engineered PCa mouse models. The combination of in vitro cell line studies and in vivo mouse models might lead to more credible results and better strategies for the study of AR roles in PCa.

Ovarian Endometrioid Adenocarcinoma with Functioning Stroma Accompanied with Endometrial Endometrioid Adenocarcinoma: Immunohistochemical Study and Literature Review

Background: The ovarian tumors with functioning stroma are defined by the morphological presence of endocrine active cells in stroma, and the clinical, biochemical or pathological evidence of endocrine function. Case Report: The ovarian endometrioid adenocarcinoma with functioning stroma accompanied with endometrial endometrioid adenocarcinoma was found in 64-year-old post-menopausal woman complaining abnormal genital bleeding and mammary distention. Her preoperative serum 17?-estradiol level was high (53.2 pg/ml) while human chorionic gonadotropin (hCG) level was within normal limit. Her right ovary with 8.8 × 5.3 cm in size and tan-yellow in color mostly consisted of solid tumor. Histologically, tumor was composed of estrogen receptor (ER)- and progesterone receptor (PgR)-positive, and androgen receptor (AR)-negative cancerous endometrial cells with aggregates of vacuolated foamy stromal cells resembling luteinized cells. These stromal cells contained lipid droplets, and was immunopositive for α-inhibin and 17?-estradiol. After surgery, serum 17?-estradiol level decreased and became normal (14.2 pg/ml). These findings indicate the production of steroid hormone (17?-estradiol) from the foamy stromal cells and may be correlated with the clinical symptoms. Furthermore, ER- and PgR-positive endometrial endometrioid adenocarcinoma developed synchronously. However, ovary and uterus were totally immunonegative for human chorionic gonadotropin (hCG). Four other cases from the literature including ours are reviewed. Conclusion: Cancer cells were positive for ER and PgR in both ovary and uterus responded to steroid hormone produced by foamy stromal cells, which played a role in proliferation and progression of ovarian and endometrial endometrioid adenocarcinoma, respectively.

肿瘤间质比和肿瘤间质浸润淋巴细胞对HER2阴性乳腺癌新辅助治疗疗效的影响

目的探讨肿瘤间质比(tumor-stroma ratio,TSR)和肿瘤间质浸润淋巴细胞(stromal tumor-infiltrating lymphocytes,sTILs)对HER2阴性乳腺癌新辅助治疗(neoadjuvant therapy,NAT)疗效的预测意义。方法收集516例术前穿刺确诊为HER2阴性乳腺浸润性癌患者,均接受NAT后进行根治性手术。评估常规HE切片中TSR和sTILs的状态,术后标本进行残余肿瘤负荷(residual cancer burden,RCB)分级、Miller-Payne(MP)分级、病理完全缓解(pathological complete response,pCR)评估。采用Pearsonχ^(2)和趋势χ^(2)检验观察TSR、sTILs、TSR联合sTILs与临床病理特征的关系;应用Logistic二元回归分析TSR、sTILs、TSR联合sTILs与pCR率的关系。结果516例乳腺癌中高TSR(间质占比≤50%)者278例(53.9%),低TSR(间质占比>50%)者238例(46.1%)。NAT前高TSR组和高sTILs组的肿瘤与较高的MP分级、较低的RCB分级显著相关,pCR率高(P<0.05)。术前活检高TSR患者pCR的概率比低TSR患者高2.163倍(OR:2.163,95%CI:1.201~3.898,P=0.010)。激素受体(hormone receptor,HR)阴性组、高TSR对NAT后患者pCR率的OR值为2.999(95%CI:1.216~7.396,P=0.017)。高TSR、高sTILs组患者NAT后pCR率是低TSR、低sTILs患者的4.052倍(OR:4.052,95%CI:1.900~8.644,P<0.001),差异均有统计学意义。结论HER2阴性乳腺癌患者治疗前活检中较高的TSR和sTILs状态与NAT后较高的MP分级和较低的RCB分级、较高的pCR率相关,术前联合评估两者可为临床治疗提供帮助。

间质化疗联合放疗治疗局部晚期胰腺癌的疗效观察

目的:观察间质化疗联合放疗治疗局部晚期胰腺癌的疗效及不良反应。方法:局部晚期胰腺癌患者48例,Ⅲ期38例,Ⅳ期10例,按随机数字分为实验组(放疗+间质化疗)和对照组(放疗+全身化疗),每组各24例患者。间质化疗:在CT引导下穿刺将氟尿嘧啶缓剂植入肿瘤体内。化疗:采用氟尿嘧啶注射剂500 mg,静滴连用5天。放疗:采用三维适形放射治疗,Dt=40GY,3GY/次,2次/周。结果:(1)近期疗效:治疗组:CR 3例,PR 13例,SD 7例,PD 1例;对照组:CR 1例,PR 8例,SD 12例,PD 3例,两组比较差异无统计学意义(χ2=4.506,P=0.212)。(2)生存率比较:1年生存率:治疗组25%,对照组12.5%,两组差异无统计学意义(χ2=2.946,P=0.086)。(3)CBR:治疗组:有效14例,稳定10例;对照组:有效10例,稳定17例,两组差异有统计学意义(χ2=4.648,P=0.042)。(4)毒性反应:Ⅰ-Ⅱ级消化道反应,治疗组15例,对照组24例,两组差异有统计学意义(χ2=11.077,P=0.001);Ⅰ-Ⅲ级消化道反应,治疗组17例,对照组24例,两组差异有统计学意义(χ2=8.195,P=0.004)。结论:间质化疗联合放疗与化疗联合放疗相比,不能提高局部晚期胰腺癌患者的近期疗效和生存率,但能提高CBR,化疗放疗不良反应轻。

多效生长因子通过诱导肿瘤血管生成、重建肿瘤微环境和活化基质纤维发挥多功能肿瘤启动子作用

多效生长因子(pleiotrophin,PTN)是分泌型的肝素结合生长因子,具有136个氨基酸,在机体内广泛表达。它能通过特殊的信号通路,即跨膜蛋白酪氨酸磷酸酶(receptor protein tyrosine phosphataseβ/ζ,RPTPβ/ζ)受体转导信号。PTN也是原癌基因,它表达在人类肿瘤细胞中,并且来源于肿瘤的细胞链也会表达PTN。不论是不同细胞诱导产生的PTN还是PTN刺激的细胞,它们的相似之处都是高度恶性。此外,将PTN转化到细胞后能使潜在恶性细胞高度恶化。因此,在恶性细胞中PTN不适当的表达能作为肿瘤强有力的启动者。最近确认,在转基因小鼠模型中发现PTN能以乳腺癌病毒为靶向目标诱导乳腺癌更具有侵略性,在表型中更相似于硬癌。另外,PTN能显著增加肿瘤血管生成,重塑肿瘤微环境。

α-SMA和MMP-9在乳腺癌中的表达及意义

目的检测乳腺癌组织中α-SMA和MMP-9的表达情况,探讨其与乳腺癌侵袭转移的关系。方法应用免疫组化通用型二步法检测58例乳腺癌中α-SMA和MMP-9的表达,并分析两者的相关性,探讨其与乳腺癌临床病理特征的关系。结果①10例正常乳腺组织中,间质纤维母细胞α-SMA(-);58例乳腺导管原位癌、导管原位癌微灶浸润和浸润性导管癌间质纤维母细胞α-SMA表达呈不同程度上调;浸润性导管癌间质纤维母细胞α-SMA表达与肿瘤大小和组织学分级无关(P>0.05),而与淋巴结转移和临床分期有关(P<0.05)。②正常乳腺组织MMP-9阳性率为20%(2/10),而乳腺浸润性导管癌中阳性率为70.7%(29/41),明显高于正常组织(P<0.01);MMP-9阳性表达与淋巴结转移、临床分期和肿瘤大小有关(P<0.05),而与乳腺癌组织学分级无关(P>0.05)。③α-SMA在乳腺浸润性导管癌相关纤维母细胞中的表达与癌细胞MMP-9的表达呈正相关(P<0.01)。结论α-SMA阳性的乳腺癌相关纤维母细胞可能参与了MMP-9降解基底膜和细胞外基质的过程,与乳腺癌侵袭转移密切相关。

乳腺癌外周血单个核细胞与间质免疫微环境的关系研究

目的探讨乳腺癌免疫微环境与外周血的关系。方法应用BRB-Array Tools软件对公共基因芯片数据库GEO中的乳腺癌间质及乳腺癌患者外周血单个核细胞基因芯片表达数据进行统计学分析,找出在乳腺癌间质及外周血单个核细胞均发生变化的基因,DAVID工具进一步分析其功能及参与的生物学通路。PINA蛋白质互作平台分析这些基因的蛋白质相互作用情况。结果比较后得到共同差异表达的103条基因,失调方向一致的基因70条,功能涉及炎症反应、髓系细胞分化、白细胞激活、抗原加工提呈等多种免疫相关的生物学过程。结论乳腺癌患者外周血单个核细胞基因表达改变,与肿瘤间质微环境具有一定相似度,有望建立基于外周血的免疫微环境分子预测,为乳腺癌的治疗靶点及预后判断的研究开辟新思路。