ADAM12 is a prognostic factor associated with an aggressive molecular subtype of high-grade serous ovarian carcinoma

Development of a novel prostate Cancer-Stroma Sphere (CSS) model for In Vitro tumor microenvironment studies

Tumor employs non-cancerous cells to gain beneficial features that promote growth and survival of cancer cells. Despite intensive research in the area of tumor microenvironment, there is still a lack of reliable and reproducible in vitro model for tumor and tumor-microenvironment cell interaction studies. Herein we report the successful development of a heterogeneous cancer-stroma sphere (CSS) model composed of prostate adenocarcinoma PC3 cells and immortalized mesenchymal stem cells (MSC). The CSS model demonstrated a structured spatial layout of the cells, with stromal cells concentrated at the center of the spheres and tumor cells located on the periphery. Significant increase in the levels of VEGFA, IL-10, and IL1a has been detected in the conditioned media of CSS as compared to PC3 spheres. Single cell RNA sequencing data revealed that VEGFA was secreted by MSC cells within heterogeneous spheroids. Enhanced expression of extracellular membrane (ECM) proteins was also shown for CSS-derived MSCs. Furthermore, we demonstrated that the multicellular architecture altered cancer cell response to chemotherapeutic agents: the inhibition of sphere formation by topotecan was 74.92 ± 4.56 % for PC3 spheres and 45.95 ± 7.84 % for CSS spheres (p < 0.01), docetaxel showed 37,51± 20,88 % and 15,67± 14,08 % inhibition, respectively (p < 0.05). Thus, CSS present an effective in vitro model for examining the extracellular matrix composition and cell-to-cell interactions within the tumor, as well as for evaluating the antitumor activity of drugs.

Depletion of slow-cycling PDGFRα+ADAM12+ mesenchymal cells promotes antitumor immunity by restricting macrophage efferocytosis

The capacity to survive and thrive in conditions of limited resources and high inflammation is a major driver of tumor malignancy. Here we identified slow-cycling ADAM12+PDGFRα+ mesenchymal stromal cells (MSCs) induced at the tumor margins in mouse models of melanoma, pancreatic cancer and prostate cancer. Using inducible lineage tracing and transcriptomics, we demonstrated that metabolically altered ADAM12+ MSCs induced pathological angiogenesis and immunosuppression by promoting macrophage efferocytosis and polarization through overexpression of genes such as Gas6, Lgals3 and Csf1. Genetic depletion of ADAM12+ cells restored a functional tumor vasculature, reduced hypoxia and acidosis and normalized CAFs, inducing infiltration of effector T cells and growth inhibition of melanomas and pancreatic neuroendocrine cancer, in a process dependent on TGF-β. In human cancer, ADAM12 stratifies patients with high levels of hypoxia and innate resistance mechanisms, as well as factors associated with a poor prognosis and drug resistance such as AXL. Altogether, our data show that depletion of tumor-induced slow-cycling PDGFRα+ MSCs through ADAM12 restores antitumor immunity.

Impact of disintegrin and metalloproteinase domain-containing protein 12 on pancreatic ductal adenocarcinoma treated with surgical resection and perioperative chemotherapy

BACKGROUND/OBJECTIVES

A disintegrin and metalloproteinase domain-containing protein 12 (ADAM12) has been reported to influence tumor progression and chemosensitivity in human cancers. We assessed the prognostic impact of ADAM12 and its predictive value for neoadjuvant chemotherapy (NAC) in patients with pancreatic ductal adenocarcinoma (PDAC) treated with surgical resection.

METHODS

ADAM12 expression was immunohistochemically examined in 428 patients with PDAC who underwent surgical resection. The association of ADAM12 expression with clinicopathological factors and survival was also analyzed.

RESULTS

Patients with high ADAM12 expression exhibited significantly shorter median disease-free survival (DFS) (high ADAM12: 17.8 vs. low ADAM12: 37.9 months; P < 0.001) and overall survival (OS) (high ADAM12: 33.1 vs. low ADAM12: 65.0 months; P < 0.001). A multivariate analysis revealed that high ADAM12 expression was an independent risk factor for poor DFS (P < 0.001) and OS (P < 0.001) in all eligible patients. Of 100 patients who received neoadjuvant chemotherapy (NAC), high ADAM12 expression was significantly associated with poor DFS in a subset of patients treated with the nab-paclitaxel (PTX) neoadjuvant regimen (P = 0.03), whereas the prognostic value of ADAM12 was not evident in patients not treated with nab-PTX (P = 0.12).

CONCLUSIONS

A negative prognostic value of high ADAM12 expression was observed in patients with PDAC treated with surgical resection, which was enhanced in patients treated with NAC, including nab-PTX. These results suggested that ADAM12 expression can predict nab-PTX chemosensitivity in PDAC and reflect PDAC progression.

Adenosine Receptor A2B Negatively Regulates Cell Migration in Ovarian Carcinoma Cells

The purinergic system is fundamental in the tumor microenvironment, since it regulates tumor cell interactions with the immune system, as well as growth and differentiation in autocrine-paracrine responses. Here, we investigated the role of the adenosine A2B receptor (A2BR) in ovarian carcinoma-derived cells’ (OCDC) properties. From public databases, we documented that high A2BR expression is associated with a better prognostic outcome in ovarian cancer patients. In vitro experiments were performed on SKOV-3 cell line to understand how A2BR regulates the carcinoma cell phenotype associated with cell migration. RT-PCR and Western blotting revealed that the ADORA2B transcript (coding for A2BR) and A2BR were expressed in SKOV-3 cells. Stimulation with BAY-606583, an A2BR agonist, induced ERK1/2 phosphorylation, which was abolished by the antagonist PSB-603. Pharmacological activation of A2BR reduced cell migration and actin stress fibers; in agreement, A2BR knockdown increased migration and enhanced actin stress fiber expression. Furthermore, the expression of E-cadherin, an epithelial marker, increased in BAY-606583-treated cells. Finally, cDNA microarrays revealed the pathways mediating the effects of A2BR activation on SKOV-3 cells. Our results showed that A2BR contributed to maintaining an epithelial-like phenotype in OCDC and highlighted this purinergic receptor as a potential biomarker.

Serum-based measurements of stromal activation through ADAM12 associate with poor prognosis in colorectal cancer

Background

Recently it has been recognized that stromal markers could be used as a clinically relevant biomarker for therapy response and prognosis. Here, we report on a serum marker for stromal activation, A Disintegrin and Metalloprotease 12 (ADAM12) in colorectal cancer (CRC).

Methods

Using gene expression databases we investigated ADAM12 expression in CRC and delineated the source of ADAM12 expression. The clinical value of ADAM12 was retrospectively assessed in the CAIRO2 trial in metastatic CRC with 235 patients (31% of total cohort), and an independent rectal cancer cohort (n = 20).

Results

ADAM12 is expressed by activated CRC associated fibroblasts. In the CAIRO2 trial cohort, ADAM12 serum levels were prognostic (ADAM12 low versus ADAM12 high; median OS 25.3 vs. 17.1 months, HR 1.48 [95% CI 1.11–1.96], P = 0.007). The prognostic potential was specifically high for metastatic rectal cancer (HR 1.78 [95% CI 1.06–3.00], P = 0.030) and mesenchymal subtype tumors (HR 2.12 [95% CI 1.25–3.60], P = 0.004). ADAM12 also showed potential for predicting recurrence in an exploratory analysis of non-metastatic rectal cancers.

Conclusions

Here we describe a non-invasive marker for activated stroma in CRC which associates with poor outcome, especially for primary cancers located in the rectum.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09436-0.

Upregulation of ADAM12 Is Associated With a Poor Survival and Immune Cell Infiltration in Colon Adenocarcinoma

BACKGROUND

A disintegrin and metalloprotease 12 (ADAM12) is a member of the multidomain protein family, but the mechanisms by which it affects prognosis and immune cell infiltration in patients with colon adenocarcinoma (COAD) remain unclear. Here, our study aimed to analyze the prognostic value of ADAM12 and investigate the correlation between ADAM12 expression and immune cell infiltration in patients with COAD.

METHODS

Differential expression analyses were performed using the Oncomine and UALCAN databases, and prognostic analyses were conducted using PrognoScan, Gene Expression Profiling Interactive Analysis (GEPIA), and Kaplan-Meier Plotter. Then, the cBioPortal database was used to analyze alterations in the ADAM12 gene, and the STRING and Metascape websites were used to conduct Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Additionally, relationships between ADAM12 and the immune microenvironment were evaluated based on the TIMER, GEPIA, and TISIDB databases.

RESULTS

ADAM12 was overexpressed in COAD tissues, and higher ADAM12 expression correlated with a worse prognosis for patients with COAD. The gene regulatory network suggested that ADAM12 was mainly enriched in extracellular matrix (ECM) organization, ECM proteoglycans, skeletal system development, and ossification, among other pathways. Moreover, ADAM12 expression significantly correlated with the abundance of CD4+ T cells, B cells, CD8+ T cells, neutrophils, macrophages, dendritic cells, and their markers, as well as lymphocytes, immunomodulators, and chemokines.

CONCLUSIONS

In colorectal tumors, ADAM12 may play vital roles in regulating the ECM and the recruitment of immune cells, and we suggest that ADAM12 will become a reliable biomarker for determining response to immunotherapy and the prognosis of patients with COAD.

Research Progress in Prognostic Factors and Biomarkers of Ovarian Cancer

Ovarian cancer is a serious threat to women's health; its early diagnosis rate is low and prone to metastasis and recurrence. The current conventional treatment for ovarian cancer is a combination of platinum and paclitaxel chemotherapy based on surgery. The recurrence and progression of ovarian cancer with poor prognosis is a major challenge in treatment. With rapid advances in technology, understanding of the molecular pathways involved in ovarian cancer recurrence and progression has increased, biomarker-guided treatment options can greatly improve the prognosis of patients. This review systematically discusses and summarizes existing and new information on prognostic factors and biomarkers of ovarian cancer, which is expected to improve the clinical management of patients and lead to effective personalized treatment.

Identification of crucial noncoding RNAs and mRNAs in hypertrophic scars via RNA sequencing

Hypertrophic scarring (HS) is a dermal fibroproliferative disorder characterized by excessive deposition of collagen and other extracellular matrix components. The aim of this study is to explore crucial long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) associated with HS and provide a better understanding of the molecular mechanism of HS. To investigate the lncRNA, circRNA and mRNA expression profiles, we performed RNA sequencing of human HS and normal skin tissues. After the identification of differentially expressed mRNAs (DEmRNAs), lncRNAs (DElncRNAs) and circRNAs (DEcircRNAs), we performed functional enrichment of DEmRNAs. Further on, we constructed DElncRNA/DEcircRNA–DEmRNA coexpression networks and competing endogenous RNA regulatory networks, and performed functional analyses of the DEmRNAs in the constructed networks. In total, 487 DEmRNAs, 92 DElncRNAs and 17 DEcircRNAs were identified. DEmRNAs were significantly enriched in processes such as collagen fibril organization, extracellular matrix–receptor interaction and the phosphatidylinositol 3‐kinase (PI3K)–Akt signaling pathway. In addition, we detected 580 DElncRNA–DEmRNA and 505 DEcircRNA–DEmRNA coexpression pairs. The competing endogenous RNA network contained 18 circRNA–microRNA (miRNA) pairs, 18 lncRNA–miRNA pairs and 409 miRNA–mRNA pairs, including 10 circRNAs, 5 lncRNAs, 15 miRNAs and 160 mRNAs. We concluded that MIR503HG/hsa‐miR‐204‐3p/ACAN, MIR503HG/hsa‐miR‐431‐5p/TNFRSF9, MEG3/hsa‐miR‐6884‐5p/ADAMTS14, AC000035.1‐ADAMTS14 and hsa_circ_0069865‐COMP/ADAM12 interaction pairs may play a central role in HS.

Epithelial/mesenchymal heterogeneity of high-grade serous ovarian carcinoma samples correlates with miRNA let-7 levels and predicts tumor growth and metastasis

Patient‐derived samples present an advantage over current cell line models of high‐grade serous ovarian cancer (HGSOC) that are not always reliable and phenotypically faithful models of in vivo HGSOC. To improve upon cell line models of HGSOC, we set out to characterize a panel of patient‐derived cells and determine their epithelial and mesenchymal characteristics. We analyzed RNA and protein expression levels in patient‐derived xenograft (PDX) models of HGSOC, and functionally characterized these models using flow cytometry, wound healing assays, invasion assays, and spheroid cultures. Besides in vitro work, we also evaluated the growth characteristics of PDX in vivo (orthotopic PDX). We found that all samples had hybrid characteristics, covering a spectrum from an epithelial‐to‐mesenchymal state. Samples with a stronger epithelial phenotype were more active in self‐renewal assays and more tumorigenic in orthotopic xenograft models as compared to samples with a stronger mesenchymal phenotype, which were more migratory and invasive. Additionally, we observed an inverse association between microRNA let‐7 (lethal‐7) expression and stemness, consistent with the loss of let‐7 being an important component of the cancer stem cell phenotype. We observed that lower let‐7 levels were associated with the epithelial state and a lower epithelial mesenchymal transition (EMT) score, more efficient spheroid and tumor formation, and increased sensitivity to platinum‐based chemotherapy. Surprisingly, in these HGSOC cells, stemness could be dissociated from invasiveness: Cells with lower let‐7 levels were more tumorigenic, but less migratory, and with a lower EMT score, than those with higher let‐7 levels. We conclude that let‐7 expression and epithelial/mesenchymal state are valuable predictors of HGSOC proliferation, in vitro self‐renewal, and tumor burden in vivo.

ADAM12 silencing promotes cellular apoptosis by activating autophagy in choriocarcinoma cells

ADAM metallopeptidase domain 12 (ADAM12) has been demonstrated to mediate cell proliferation and apoptosis resistance in several types of cancer cells. However, the effect of ADAM12 silencing on the proliferation and apoptosis of choriocarcinoma cells remains unknown. The present study revealed that ADAM12 silencing significantly inhibited cellular activity and proliferation in the human choriocarcinoma JEG3 cell line and increased the rate of apoptosis. In addition, ADAM12 silencing significantly increased the expression levels of the autophagy proteins microtubule-associated protein-light-chain 3 (LC3B) and autophagy related 5 (ATG5) and the fluorescence density of LC3B in JEG-3 cells. However, the suppression of autophagy by 3-methyladenine could block ADAM12 silencing-induced cellular apoptosis. ADAM12 silencing reduced the levels of the inflammatory factors interleukin-1β, interferon-γ and TNF-α, and inactivated nuclear p65-NF-κB and p-mTOR in JEG-3 cells. The downregulation of p-mTOR expression by ADAM12 silencing was rescued in 3-methyladenine-treated JEG-3 cells, indicating that mTOR might participate in the autophagy-mediated pro-apoptotic effect of ADAM12 silencing. In conclusion, ADAM12 silencing promoted cellular apoptosis in human choriocarcinoma JEG3 cells, which might be associated with autophagy and the mTOR response. These findings indicate that ADAM12 silencing might be a potential novel therapeutic target for choriocarcinoma.

ADAM proteases: Emerging role and targeting of the non-catalytic domains

ADAM proteases are multi domain transmembrane metalloproteases that cleave a range of cell surface proteins and activate signaling pathways implicated in tumor progression, including those mediated by Notch, EFGR, and the Eph receptors. Consequently, they have emerged as key therapeutic targets in the efforts to inhibit tumor initiation and progression. To that end, two main approaches have been taken to develop ADAM antagonists: (i) small molecule inhibitors, and (ii) monoclonal antibodies. In this mini-review we describe the distinct features of ADAM proteases, particularly of ADAM10 and ADAM17, their domain organization, conformational rearrangements, regulation, as well as their emerging importance as therapeutic targets in cancer. Further, we highlight an anti-ADAM10 monoclonal antibody that we have recently developed, which has shown significant promise in inhibiting Notch signaling and deterring growth of solid tumors in pre-clinical settings.

Metalloproteinases and their roles in human cancer

It is now widely appreciated that members of the matrix metalloproteinase (MMP) family of enzymes play a key role in cancer development and progression along with many of the hallmarks associated with them. The activity of these enzymes has been directly implicated in extracellular matrix remodeling, the processing of growth factors and receptors, the modulation of cell migration, proliferation, and invasion, the epithelial to mesenchymal transition, the regulation of immune responses, and the control of angiogenesis. Certain MMP family members have been validated as biomarkers of a variety of human cancers including those of the breast, brain, pancreas, prostate, ovary, and others. The related metalloproteinases, the A disintegrin and metalloproteinases (ADAMs), share a number of these functions as well. Here, we explore these essential metalloproteinases and some of their disease-associated activities in detail as well as some of their complementary translational potential. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Genes associated with bowel metastases in ovarian cancer

OBJECTIVE

This study is designed to identify genes and pathways that could promote metastasis to the bowel in high-grade serous ovarian cancer (OC) and evaluate their associations with clinical outcomes.

METHODS

We performed RNA sequencing of OC primary tumors (PTs) and their corresponding bowel metastases (n = 21 discovery set; n = 18 replication set). Differentially expressed genes (DEGs) were those expressed at least 2-fold higher in bowel metastases (BMets) than PTs in at least 30% of patients (P < .05) with no increased expression in paired benign bowel tissue and were validated with quantitative reverse transcription PCR. Using an independent OC cohort (n = 333), associations between DEGs in PTs and surgical and clinical outcomes were performed. Immunohistochemistry and mouse xenograft studies were performed to confirm the role of LRRC15 in promoting metastasis.

RESULTS

Among 27 DEGs in the discovery set, 21 were confirmed in the replication set: SFRP2, Col11A1, LRRC15, ADAM12, ADAMTS12, MFAP5, LUM, PLPP4, FAP, POSTN, GRP, MMP11, MMP13, C1QTNF3, EPYC, DIO2, KCNA1, NETO1, NTM, MYH13, and PVALB. Higher expression of more than half of the genes in the PT was associated with an increased requirement for bowel resection at primary surgery and an inability to achieve complete cytoreduction. Increased expression of LRRC15 in BMets was confirmed by immunohistochemistry and knockdown of LRRC15 significantly inhibited tumor progression in mice.

CONCLUSIONS

We identified 21 genes that are overexpressed in bowel metastases among patients with OC. Our findings will help select potential molecular targets for the prevention and treatment of malignant bowel obstruction in OC.

FOXC2 augments tumor propagation and metastasis in osteosarcoma

Osteosarcoma is a highly malignant tumor that contains a small subpopulation of tumor-propagating cells (also known as tumor-initiating cells) characterized by drug resistance and high metastatic potential. The molecular mechanism by which tumor-propagating cells promote tumor growth is poorly understood. Here, we report that the transcription factor forkhead box C2 (FOXC2) is frequently expressed in human osteosarcomas and is important in maintaining osteosarcoma cells in a stem-like state. In osteosarcoma cell lines, we show that anoikis conditions stimulate FOXC2 expression. Downregulation of FOXC2 decreases anchorage-independent growth and invasion in vitro and lung metastasis in vivo, while overexpression of FOXC2 increases tumor propagation in vivo. In osteosarcoma cell lines, we demonstrate that high levels of FOXC2 are associated with and required for the expression of osteosarcoma tumor-propagating cell markers. In FOXC2 knockdown cell lines, we show that CXCR4, a downstream target of FOXC2, can restore osteosarcoma cell invasiveness and metastasis to the lung.

Genetic variants of genes in the Notch signaling pathway predict overall survival of non-small cell lung cancer patients in the PLCO study

The Notch signaling pathway has been shown to have biological significance and therapeutic application in non-small cell lung cancer (NSCLC). We hypothesize that genetic variants of genes in the Notch signaling pathway are associated with overall survival (OS) of NSCLC patients. To test this hypothesis, we performed multivariate Cox proportional hazards regression analysis to evaluate associations of 19,571 single nucleotide polymorphisms (SNPs) in 132 Notch pathway genes with OS of 1,185 NSCLC patients available from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. We found that five potentially functional tagSNPs in four genes (i.e., ADAM12 rs10794069 A > G, DTX1 rs1732793 G > A, TLE1 rs199731120 C > CA, TLE1 rs35970494 T > TC and E2F3 rs3806116 G > T) were associated with a poor OS, with a variant-allele attributed hazards ratio (HR) of 1.27 [95% confidence interval (95% CI) = 1.13–1.42, P = 3.62E-05], 1.30 (1.14–1.49, 8.16E-05), 1.40 (1.16–1.68, 3.47E-04), 1.27 (1.11–1.44, 3.38E-04), and 1.21 (1.09–1.33, 2.56E-04), respectively. Combined analysis of these five risk genotypes revealed that the genetic score 0–5 was associated with the adjusted HR in a dose-response manner (P_trend = 3.44E-13); individuals with 2–5 risk genotypes had an adjusted HR of 1.56 (1.34–1.82, 1.46E-08), compared with those with 0–1 risk genotypes. Larger studies are needed to validate our findings.

ADAM9 is over-expressed in human ovarian clear cell carcinomas and suppresses cisplatin-induced cell death

ADAMs (a disintegrin and metalloproteinases) are involved in various biological events such as cell adhesion, migration and invasion, membrane protein shedding and proteolysis. However, there have been no systematic studies on the expression of ADAMs in human ovarian carcinomas. We therefore examined mRNA expression of all the proteolytic ADAM species including ADAM8, 9, 10, 12, 15, 17, 19, 20, 21, 28, 30, 33 and ADAMDEC1 in human ovarian carcinomas, and found that prototype membrane-anchored ADAM9m, but not secreted isoform ADAM9s, is significantly over-expressed in carcinomas than in control non-neoplastic ovarian tissue. Among the histological subtypes of serous, endometrioid, mucinous and clear cell carcinomas, ADAM9m expression was highest in clear cell carcinomas. Immunohistochemistry showed that all the clear cell carcinoma samples displayed ADAM9m primarily on the carcinoma cell membrane. By immunoblotting, ADAM9m was detected mainly in an active form in the clear cell carcinoma tissues. When two clear cell carcinoma cell lines (RMG-I and TOV21G cells) with ADAM9m expression were treated with cisplatin, viability was significantly reduced and apoptosis increased in ADAM9m knockdown cells compared with mock transfectants. In addition, treatment of the cells with neutralizing anti-ADAM9m antibody significantly decreased viability compared with non-immune IgG, whereas ADAM9m over-expression significantly increased viability compared with mock transfectants. Our data show, to the best of our knowledge, for the first time, that ADAM9m is over-expressed in an activated form in human ovarian clear cell carcinomas, and suggest that ADAM9m plays a key role in cisplatin resistance.

ADAM12 Is a Novel Regulator of Tumor Angiogenesis via STAT3 Signaling

ADAM12, (ADisintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608-22. ©2017 AACR.

Matricellular protein SPARCL1 regulates tumor microenvironment-dependent endothelial cell heterogeneity in colorectal carcinoma

Different tumor microenvironments (TMEs) induce stromal cell plasticity that affects tumorigenesis. The impact of TME-dependent heterogeneity of tumor endothelial cells (TECs) on tumorigenesis is unclear. Here, we isolated pure TECs from human colorectal carcinomas (CRCs) that exhibited TMEs with either improved (Th1-TME CRCs) or worse clinical prognosis (control-TME CRCs). Transcriptome analyses identified markedly different gene clusters that reflected the tumorigenic and angiogenic activities of the respective TMEs. The gene encoding the matricellular protein SPARCL1 was most strongly upregulated in Th1-TME TECs. It was also highly expressed in ECs in healthy colon tissues and Th1-TME CRCs but low in control-TME CRCs. In vitro, SPARCL1 expression was induced in confluent, quiescent ECs and functionally contributed to EC quiescence by inhibiting proliferation, migration, and sprouting, whereas siRNA-mediated knockdown increased sprouting. In human CRC tissues and mouse models, vessels with SPARCL1 expression were larger and more densely covered by mural cells. SPARCL1 secretion from quiescent ECs inhibited mural cell migration, which likely led to stabilized mural cell coverage of mature vessels. Together, these findings demonstrate TME-dependent intertumoral TEC heterogeneity in CRC. They further indicate that TEC heterogeneity is regulated by SPARCL1, which promotes the cell quiescence and vessel homeostasis contributing to the favorable prognoses associated with Th1-TME CRCs.

Elucidation of the molecular mechanisms of anaplastic thyroid carcinoma by integrated miRNA and mRNA analysis

To elucidate the complex molecular mechanisms of anaplastic thyroid carcinoma (ATC), the mRNA and miRNA expression profiles of ATC were systematically explored. A total of 55 common differentially expressed genes (DEGs) were obtained from two mRNA expression datasets including 23 ATC samples and 24 paired normal samples. Gene expression levels of three randomly selected DEGs, VCAN, COL5A1 and KCNJ16, were examined using RT-PCR in 10 ATC samples. Notably, the ATC and normal samples were clearly classified into two groups based on their common DEGs. Moreover 23 common DEGs, such as TG, NKX2-1, KCNJ16 and CTHRC1, were predicted to be the potential targets of 17 identified miRNAs in ATC. Meanwhile, several miRNA target genes were associated with biological processes related to tumor progression such as angiogenesis, cell migration or growth and potassium channel regulation. In summary, the poor prognosis of ATC is possibly caused via complex biological processes. Firstly, angiogenesis was activated by the high expression of CTHRC1, VCAN and POSTN, providing necessary nutrition for tumor cells. Then tumor distant metastasis was induced via stimulation of cell migration and cell growth or regulation of cell-cell interaction. Moreover, intracellular potassium concentration changes promoted ATC progression indirectly. Hence, identification of these critical DEGs was valuable in understanding the molecular mechanisms of ATC.