CD147-dependent heterogeneity in malignant and chemoresistant properties of cancer cells

EMMPRIN promotes spheroid organization and metastatic formation: comparison between monolayers and spheroids of CT26 colon carcinoma cells

Background

In vitro studies often use two-dimensional (2D) monolayers, but 3D cell organization, such as in spheroids, better mimics the complexity of solid tumors. To metastasize, cancer cells undergo the process of epithelial-to-mesenchymal transition (EMT) to become more invasive and pro-angiogenic, with expression of both epithelial and mesenchymal markers.

Aims

We asked whether EMMPRIN/CD147 contributes to the formation of the 3D spheroid structure, and whether spheroids, which are often used to study proliferation and drug resistance, could better model the EMT process and the metastatic properties of cells, and improve our understanding of the role of EMMPRIN in them.

Methods

We used the parental mouse CT26 colon carcinoma (CT26-WT) cells, and infected them with a lentivirus vector to knock down EMMPRIN expression (CT26-KD cells), or with an empty lentivirus vector (CT26-NC) that served as a negative control. In some cases, we repeated the experiments with the 4T1 or LLC cell lines. We compared the magnitude of change between CT26-KD and CT26-WT/NC cells in different metastatic properties in cells seeded as monolayers or as spheroids formed by the scaffold-free liquid overlay method.

Results

We show that reduced EMMPRIN expression changed the morphology of cells and their spatial organization in both 2D and 3D models. The 3D models more clearly demonstrated how reduced EMMPRIN expression inhibited proliferation and the angiogenic potential, while it enhanced drug resistance, invasiveness, and EMT status, and moreover it enhanced cell dormancy and prevented CT26-KD cells from forming metastatic-like lesions when seeded on basement membrane extract (BME). Most interestingly, this approach enabled us to identify that EMMPRIN and miR-146a-5p form a negative feedback loop, thus identifying a key mechanism for EMMPRIN activities. These results underline EMMPRIN role as a gatekeeper that prevents dormancy, and suggest that EMMPRIN links EMT characteristics to the process of spheroid formation.

Conclusions

Thus, 3D models can help identify mechanisms by which EMMPRIN facilitates tumor and metastasis progression, which might render EMMPRIN as a promising target for anti-metastatic tumor therapy.

Natural Cyclophilin A Inhibitors Suppress the Growth of Cancer Stem Cells in Non-Small Cell Lung Cancer by Disrupting Crosstalk between CypA/CD147 and EGFR

Non-small cell lung cancer (NSCLC) is a fatal malignant tumor with a high mortality rate. Cancer stem cells (CSCs) play pivotal roles in tumor initiation and progression, treatment resistance, and NSCLC recurrence. Therefore, the development of novel therapeutic targets and anticancer drugs that effectively block CSC growth may improve treatment outcomes in patients with NSCLC. In this study, we evaluated, for the first time, the effects of natural cyclophilin A (CypA) inhibitors, including 23-demethyl 8,13-deoxynargenicin (C9) and cyclosporin A (CsA), on the growth of NSCLC CSCs. C9 and CsA more sensitively inhibited the proliferation of epidermal growth factor receptor (EGFR)-mutant NSCLC CSCs than EGFR wild-type NSCLC CSCs. Both compounds suppressed the self-renewal ability of NSCLC CSCs and NSCLC-CSC-derived tumor growth in vivo. Furthermore, C9 and CsA inhibited NSCLC CSC growth by activating the intrinsic apoptotic pathway. Notably, C9 and CsA reduced the expression levels of major CSC markers, including integrin α6, CD133, CD44, ALDH1A1, Nanog, Oct4, and Sox2, through dual downregulation of the CypA/CD147 axis and EGFR activity in NSCLC CSCs. Our results also show that the EGFR tyrosine kinase inhibitor afatinib inactivated EGFR and decreased the expression levels of CypA and CD147 in NSCLC CSCs, suggesting close crosstalk between the CypA/CD147 and EGFR pathways in regulating NSCLC CSC growth. In addition, combined treatment with afatinib and C9 or CsA more potently inhibited the growth of EGFR-mutant NSCLC CSCs than single-compound treatments. These findings suggest that the natural CypA inhibitors C9 and CsA are potential anticancer agents that suppress the growth of EGFR-mutant NSCLC CSCs, either as monotherapy or in combination with afatinib, by interfering with the crosstalk between CypA/CD147 and EGFR.

CD147 and cyclophilin A: a promising potential targeted therapy for COVID-19 and associated cancer progression and chemo-resistance

Coronavirus disease-2019 (COVID-19), as a worldwide serious issue has been shown to lead to progression and poor outcomes in cancer patients. The underlying mechanisms for SARS-CoV-2 infection's adverse effects on cancer patients have not been fully understood. We hypothesized that CD147 and Cyclophilin A (CyPA) not only can play a significant role in infection severity but also can contribute to cancer progression and chemotherapy resistance in cancer patients with COVID-19. In addition, we hypothesized that the expression of both CD147 and CyPA could be increased by Hypoxia-inducible Factor-1 alpha (HIF-1α) activation during hypoxic conditions that occurred during COVID-19. Therefore, this evidence can open a new window in the management of cancer patients during the pandemic and therapeutic approaches targeting CD147 and CyPA could be a potentially promising therapeutic approach for such patients.

The Multiple Roles of CD147 in the Development and Progression of Oral Squamous Cell Carcinoma: An Overview

Cluster of differentiation (CD)147, also termed extracellular matrix metalloprotease inducer or basigin, is a glycoprotein ubiquitously expressed throughout the human body, the oral cavity included. CD147 actively participates in physiological tissue development or growth and has important roles in reactive processes such as inflammation, immunity, and tissue repair. It is worth noting that deregulated expression and/or activity of CD147 is observed in chronic inflammatory or degenerative diseases, as well as in neoplasms. Among the latter, oral squamous cell carcinoma (OSCC) is characterized by an upregulation of CD147 in both the neoplastic and normal cells constituting the tumor mass. Most interestingly, the expression and/or activity of CD147 gradually increase as healthy oral mucosa becomes inflamed; hyperplastic/dysplastic lesions are then set on, and, eventually, OSCC develops. Based on these findings, here we summarize published studies which evaluate whether CD147 could be employed as a marker to monitor OSCC development and progression. Moreover, we describe CD147-promoted cellular and molecular events which are relevant to oral carcinogenesis, with the aim to provide useful information for assessing whether CD147 may be the target of novel therapeutic approaches directed against OSCC.

Mini-Review: Can the Metastatic Cascade Be Inhibited by Targeting CD147/EMMPRIN to Prevent Tumor Recurrence?

Solid tumors metastasize very early in their development, and once the metastatic cell is lodged in a remote organ, it can proliferate to generate a metastatic lesion or remain dormant for long periods. Dormant cells represent a real risk for future tumor recurrence, but because they are typically undetectable and insensitive to current modalities of treatment, it is difficult to treat them in time. We describe the metastatic cascade, which is the process that allows tumor cells to detach from the primary tumor, migrate in the tissue, intravasate and extravasate the lymphatics or a blood vessel, adhere to a remote tissue and eventually outgrow. We focus on the critical enabling role of the interactions between tumor cells and immune cells, especially macrophages, in driving the metastatic cascade, and on those stages that can potentially be targeted. In order to prevent the metastatic cascade and tumor recurrence, we would need to target a molecule that is involved in all of the steps of the process, and evidence is brought to suggest that CD147/EMMPRIN is such a protein and that targeting it blocks metastasis and prevents tumor recurrence.

Knockout of CD147 inhibits the proliferation, invasion, and drug resistance of human oral cancer CAL27 cells in Vitro and in Vivo

With the development of modern biomedicine, research on the molecular mechanism of tumors has developed gradually. The CD147 gene has been applied to tumor molecular targeted therapy, and significant differences were found in the expression of the CD147 gene in different tumor tissues and normal tissues. Many previous studies have also shown that the expression of the CD147 gene plays a crucial role in the development of tumors. To understand whether CD147 can be used as a therapeutic target for oral cancer, CRISPR/Cas9 gene-editing technology was used to knock out the CD147 gene in cal27 cells to obtain knockout cell lines. Using CCK-8, Transwell, RT-PCR, and Western blotting, the proliferation and invasion abilities of the knockout cell lines were decreased significantly, and the expression of matrix metalloproteinase was also inhibited. Next, a subcutaneously transplanted tumor model in nude mice was constructed to detect the effect of the CD147 gene on tumors. Subcutaneous tumor growth and immunohistochemistry results showed that the proliferation and doxorubicin resistance of knockout cell line were significantly inhibited compared with those in the wild-type group. These results indicated that knocking out CD147 significantly reduced the proliferation and invasion of cal27 cells, and CD147 may be a potential therapeutic target for oral cancer.

Detachment Activated CyPA/CD147 Induces Cancer Stem Cell Potential in Non-stem Breast Cancer Cells

BACKGROUND

Cancer stem cells (CSCs), responsible for cancer metastasis and recurrence, are generated from non-CSCs after chemo-radiation therapy. This study investigated the induction of CSC potential in non-stem breast cancer cells and the underlying molecular mechanisms in detachment culture.

METHODS

Bulk breast cancer cells, or sorted non-CSCs and CSCs were cultured under an attached or detached condition to assess CSC numbers, ability to form tumor spheres, expression of stemness markers, and chemoresistance. Lentivirus carrying CD147 shRNA or cDNA was used to manipulate CD147 expression, while CD147 ligand recombinant cyclophilin A (CyPA) or its inhibitor was used to activate or inhibit CD147 signaling.

RESULTS

Detachment promoted anoikis resistance, chemoresistance, sphere formation, self-renewal, and expression of stemness markers in breast cancer cells. Detachment increased functional ALDH⁺ or CD44^highCD24^-/low CSCs, and induced CSC potential in ALDH^- or CD44 ^low CD24^high non-CSCs. Upon detachment, both CD147 expression and CyPA secretion were enhanced, and CyPA-CD147 activation mediated detachment induced CSC potential in non-CSCs via STAT3 signaling. Clinically, CD147 and pSTAT3 were highly co-expressed and correlated with poor overall survival and tumor recurrence in breast cancer patients.

CONCLUSION

This study demonstrates that detachment induces the generation of CSCs from non-stem breast cancer cells via CyPA-CD147 signaling, indicating that targeting CD147 may serve as a potential novel therapeutic strategy for lethal metastatic breast cancer by eliminating induced CSCs.

Modeling Neoadjuvant chemotherapy resistance in vitro increased NRP-1 and HER2 expression and converted MCF7 breast cancer subtype

BACKGROUND AND PURPOSE

Patients with locally advanced breast cancer usually receive third-generation neoadjuvant chemotherapy (NAC). Although NAC treatment improved the overall survival, patients' response varies, some acquire resistance and others exhibit a conversion in their breast cancer molecular subtype. We aimed to identify the molecular changes involved in NAC resistance attempting to find new therapeutic targets in different breast cancer subtypes.

EXPERIMENTAL APPROACH

We modelled NAC treatments used in clinical practice and generated resistant cell lines in vitro. The resistant cells were generated by consecutive treatment with four cycles of doxorubicin (adriamycin)/cyclophosphamide (4xAC) followed by an additional four cycles of paclitaxel (4xAC + 4xPAC).

KEY RESULTS

Our data revealed distinct mechanisms of resistance depending on breast cancer subtype and drugs used. MDA-MB-231 cells resistant to 4xAC + 4xPAC activated neuropilin-1/TNC/integrin β3/FAK/NF-κB_p65 axis and displayed a decrease in breast cancer resistance protein (BCRP/ABCB2). However, MCF7 cells resistant to 4xAC treatments induced HER2 expression, which converted MCF7 subtype from luminal A to luminal B HER2 type, up-regulated neuropilin-1, oestrogen receptor-α, and EGFR, and activated PI3K/Akt/NF-κB_p65 axis. However, MCF7 cells resistant to 4xAC + 4xPAC exhibited down-regulation of the survival axis and up-regulated BCRP/ABCG2. Co-immunoprecipitation demonstrated a novel interaction between HER2 and neuropilin-1 driving the resistance features.

CONCLUSIONS AND IMPLICATIONS

The concurrent increase in neuropilin-1 and HER2 upon resistance and the inverse relationship between neuropilin-1 and BCRP/ABCG2 suggest that, in addition to HER2, neuropilin-1 status should be assessed in patients undergoing NAC, and as a potential drug target for refractory breast cancer.

The CD147-HYALURONAN Axis in Cancer

CD147 (basigin; EMMPRIN), hyaluronan, and hyaluronan receptors (e.g., CD44) are intimately involved in several phenomena that underlie malignancy. A major avenue whereby they influence tumor progression is most likely their role in the characteristics of cancer stem cells (CSCs), subpopulations of tumor cells that exhibit chemoresistance, invasiveness, and potent tumorigenicity. Both CD147 and hyaluronan have been strongly implicated in chemoresistance and invasiveness, and may be drivers of CSC characteristics, since current evidence indicates that both are involved in epithelial-mesenchymal transition, a crucial process in the acquisition of CSC properties. Hyaluronan is a prominent constituent of the tumor microenvironment whose interactions with cell surface receptors influence several signaling pathways that lead to chemoresistance and invasiveness. CD147 is an integral plasma membrane glycoprotein of the Ig superfamily and cofactor in assembly and activity of monocarboxylate transporters (MCTs). CD147 stimulates hyaluronan synthesis and interaction of hyaluronan with its receptors, in particular CD44 and LYVE-1, which in turn result in activation of multiprotein complexes containing members of the membrane-type matrix metalloproteinase, receptor tyrosine kinase, ABC drug transporter, or MCT families within lipid raft domains. Multivalent hyaluronan-receptor interactions are essential for formation or stabilization of these lipid raft complexes and for downstream signaling pathways or transporter activities. We conclude that stimulation of hyaluronan-receptor interactions by CD147 and the consequent activities of these complexes may be critical to the properties of CSCs and their role in malignancy. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

CD147 expression is associated with poor overall survival in chemotherapy treated triple-negative breast cancer

AIMS

In breast cancer models, the functional roles of CD147 in proliferation, invasion and treatment resistance have been widely reported. However, there are only a few studies examining the clinicopathological correlation and prognostic relevance of CD147 in breast cancer, especially in relation to breast cancer molecular subtypes.

METHODS

In this study, we analysed CD147 expression in a large cohort of breast cancers, correlating with clinicopathological features and the expression of a comprehensive panel of biomarkers in triple-negative breast cancer (TNBC) and non-TNBC subsets. Its relationship with patients' survival was also analysed.

RESULTS

CD147 was expressed in 11.9%(140/1174) of all cases and in 23.8% (40/168) of TNBC. The expression was associated with tumour histological subtypes (p=0.01) and most commonly seen in carcinoma with medullary features (26.0%). CD147 expression correlated with high tumour grade, presence of necrosis and basal-like breast cancer (BLBC) subtype, high Ki67 and expression of some other basal markers and stem-like markers. CD147 expression was also associated with poor overall survival in chemotherapy treated patients with TNBC.

CONCLUSIONS

CD147 is a putative marker in identifying TNBC or BLBC, and may be useful as a prognosis indicator for patients with TNBC or BLBC post chemotherapy.

Elevated CD147 expression is associated with shorter overall survival in non-small cell lung cancer

A number of studies have reported on the prognostic role of CD147 expression in non-small cell lung cancer (NSCLC); however, the results remain controversial. This study aims to investigate the impact of CD147 on the prognosis of NSCLC by means of a meta-analysis. A literature search was performed for relevant studies published before October 29, 2016. The hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated as effective measures. Sensitivity analysis and publication bias examination were also conducted. Ten eligible studies with a total of 1605 patients were included in this meta-analysis. CD147 overexpression was correlated with poor overall survival (OS) (HR=1.59, 95% CI=1.32-1.91, p<0.001). Elevated CD147 expression was associated with the presence of lymph node metastasis (OR=2.31, 95% CI=1.74-3.07, p<0.001) and advanced TNM stage (OR=3.03, 95% CI=1.24-7.39, p=0.015). However, no significant association between CD147 and sex, age, differentiation, or histology was found. No evidence of significant publication bias was identified. This meta-analysis revealed that overexpression of CD147 was associated with shorter OS, the presence of lymph node metastasis and advanced TNM stage in NSCLC. Therefore, CD147 could serve as a potential prognostic marker for NSCLC.

In vitro elucidation of the role of pericellular matrix in metastatic extravasation and invasion of breast carcinoma cells

Numerous studies have demonstrated the importance of altered hyaluronan metabolism to malignant progression of multiple tumor types, including breast carcinomas. Increased hyaluronan (HA) metabolism in the stroma of primary tumors promotes activation of oncogenic signaling pathways that impact tumor initiation, growth, and invasion. Carcinoma cell synthesis and assembly of HA-rich pericellular matrices induces a stromal-independent phenotype, which is associated with cancer progression. Although the pro-tumorigenic role of stromal HA is well established, a novel but unexplored hypothesis is that carcinoma cell-associated HA pericellular matrices promote metastasis of circulating tumor cells. Here, we report the development of an in vitro assay that employs microfluidic techniques to directly measure the importance of an HA-rich pericellular matrix in the entry of carcinoma cells into ectopic sites. This model provides the capability to visualize specific steps in metastasis, which is difficult using animal models. The results show that the presence of a HA-rich pericellular matrix correlates to the invasive and metastatic potential of breast carcinoma cells. Furthermore, enzymatic removal or pharmacologic inhibition of HA synthesis significantly inhibits carcinoma cell extravasation and invasion in this model system. These results implicate pericellular HA-rich carcinoma cell associated pericellular matrices in colonization of ectopic sites by circulating tumor cells and support specific targeting of this matrix to limit metastasis in patients.

HATRIC-based identification of receptors for orphan ligands

Cellular responses depend on the interactions of extracellular ligands, such as nutrients, growth factors, or drugs, with specific cell-surface receptors. The sensitivity of these interactions to non-physiological conditions, however, makes them challenging to study using in vitro assays. Here we present HATRIC-based ligand receptor capture (HATRIC-LRC), a chemoproteomic technology that successfully identifies target receptors for orphan ligands on living cells ranging from small molecules to intact viruses. HATRIC-LRC combines a click chemistry-based, protein-centric workflow with a water-soluble catalyst to capture ligand-receptor interactions at physiological pH from as few as 1 million cells. We show HATRIC-LRC utility for general antibody target validation within the native nanoscale organization of the surfaceome, as well as receptor identification for a small molecule ligand. HATRIC-LRC further enables the identification of complex extracellular interactomes, such as the host receptor panel for influenza A virus (IAV), the causative agent of the common flu.

Technologies for identifying receptor-ligand pairs on living cells at physiological conditions remain scarce. Here, the authors develop a mass spectrometry-based ligand receptor capture technology that can identify receptors for a diverse range of ligands at physiological pH with as few as a million cells.

Cancer stem cell markers in patterning differentiation and in prognosis of oral squamous cell carcinoma

Differentiation is a major histological parameter determining tumor aggressiveness and prognosis of the patient; cancer stem cells with their slow dividing and undifferentiated nature might be one of the factors determining the same. This study aims to correlate cancer stem cell markers (CD44 and CD147) with tumor differentiation and evaluate their subsequent effect on prognosis. Immunohistochemical analysis in treatment naïve oral cancer patients (n = 53) indicated that the expression of CD147 was associated with poorly differentiated squamous cell carcinoma and moderately differentiated squamous cell carcinoma (p < 0.01). Furthermore, co-expression analysis showed that 45% each of moderately differentiated squamous cell carcinoma and poorly differentiated squamous cell carcinoma patients were CD44^high/CD147^high as compared to only 10% of patients with well-differentiated squamous cell carcinoma. A three-way analysis indicated that differentiation correlated with recurrence and survival (p < 0.05) in only the patients with CD44^high/CD147^high cohort. Subsequently, relevance of these cancer stem cell markers in patterning the differentiation characteristics was evaluated in oral squamous cell carcinoma cell lines originating from different grades of oral cancer. Flowcytometry-based analysis indicated an increase in CD44⁺/CD147⁺ cells in cell lines of poorly differentiated squamous cell carcinoma (94.35 ± 1.14%, p < 0.001) and moderately differentiated squamous cell carcinoma origin (93.49 ± 0.47%, p < 0.001) as compared to cell line of well-differentiated squamous cell carcinoma origin (23.12% ± 0.49%). Expression profiling indicated higher expression of cancer stem cell and epithelial-mesenchymal transition markers in SCC029B (poorly differentiated squamous cell carcinoma originated; p ≤ 0.001), which was further translated into increased spheroid formation, migration, and invasion (p < 0.001) as compared to cell line of well-differentiated squamous cell carcinoma origin. This study suggests that CD44 and CD147 together improve the prognostic efficacy of tumor differentiation; in vitro results further point out that these markers might be determinant of differentiation characteristics, imparting properties of increased self-renewal, migration, and invasion.

A Cell-Surface Membrane Protein Signature for Glioblastoma

We present a systems strategy that facilitated the development of a molecular signature for glioblastoma (GBM), composed of 33 cell-surface transmembrane proteins. This molecular signature, GBMSig, was developed through the integration of cell-surface proteomics and transcriptomics from patient tumors in the REMBRANDT (n = 228) and TCGA datasets (n = 547) and can separate GBM patients from control individuals with a Matthew's correlation coefficient value of 0.87 in a lock-down test. Functionally, 17/33 GBMSig proteins are associated with transforming growth factor β signaling pathways, including CD47, SLC16A1, HMOX1, and MRC2. Knockdown of these genes impaired GBM invasion, reflecting their role in disease-perturbed changes in GBM. ELISA assays for a subset of GBMSig (CD44, VCAM1, HMOX1, and BIGH3) on 84 plasma specimens from multiple clinical sites revealed a high degree of separation of GBM patients from healthy control individuals (area under the curve is 0.98 in receiver operating characteristic). In addition, a classifier based on these four proteins differentiated the blood of pre- and post-tumor resections, demonstrating potential clinical value as biomarkers.

Comparative proteomics of a model MCF10A-KRasG12V cell line reveals a distinct molecular signature of the KRasG12V cell surface

Oncogenic Ras mutants play a major role in the etiology of most aggressive and deadly carcinomas in humans. In spite of continuous efforts, effective pharmacological treatments targeting oncogenic Ras isoforms have not been developed. Cell-surface proteins represent top therapeutic targets primarily due to their accessibility and susceptibility to different modes of cancer therapy. To expand the treatment options of cancers driven by oncogenic Ras, new targets need to be identified and characterized at the surface of cancer cells expressing oncogenic Ras mutants. Here, we describe a mass spectrometry-based method for molecular profiling of the cell surface using KRasG12V transfected MCF10A (MCF10A-KRasG12V) as a model cell line of constitutively activated KRas and native MCF10A cells transduced with an empty vector (EV) as control. An extensive molecular map of the KRas surface was achieved by applying, in parallel, targeted hydrazide-based cell-surface capturing technology and global shotgun membrane proteomics to identify the proteins on the KRasG12V surface. This method allowed for integrated proteomic analysis that identified more than 500 cell-surface proteins found unique or upregulated on the surface of MCF10A-KRasG12V cells. Multistep bioinformatic processing was employed to elucidate and prioritize targets for cross-validation. Scanning electron microscopy and phenotypic cancer cell assays revealed changes at the cell surface consistent with malignant epithelial-to-mesenchymal transformation secondary to KRasG12V activation. Taken together, this dataset significantly expands the map of the KRasG12V surface and uncovers potential targets involved primarily in cell motility, cellular protrusion formation, and metastasis.

CD147 and Prostate Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Prostate cancer is one of the most common non-cutaneous malignancies in men. We aimed to systemically evaluate the relationship between the expression of CD147 in tissues and the clinicopathological features of prostate cancer.

METHODS AND FINDINGS

PubMed (1966-2016), EMBASE (1980-2016), the Cochrane Library (1996-2016), Web of Science (1945-2016), China National Knowledge Infrastructure (1982-2016), and the WanFang databases (1988-2016) were searched. Literature quality assessment was performed with the Newcastle-Ottawa Scale. Meta-analysis was performed by using Review Manager 5.3 and Stata 13.0. A total of 12591 prostate cancer patients from 14 studies were included. The results of the meta-analysis showed that there were significant differences in the positive expression rate in the following comparisons: prostatic cancer tissues vs. normal prostate tissues (odds ratio [OR] = 26.93, 95% confidence interval [CI] 7.95-91.20, P < 0.00001), prostatic cancer tissues vs. benign prostatic hyperplasia tissues (OR = 20.54, 95% CI 8.20-51.44, P < 0.00001), high Gleason score vs. low Gleason score (OR = 2.39, 95% CI 1.33-4.27, P = 0.03), TNM III to IV vs. TNM I to II (OR = 9.95, 95% CI 4.96-19.96, P < 0.00001), low or moderate differentiation vs. high differentiation (OR = 8.12, 95% CI 3.69-17.85, P < 0.00001), lymph node metastasis vs. non-lymph node metastasis (OR = 4.31, 95% CI 1.11-16.71, P = 0.03), and distant metastasis vs. non-distant metastasis (OR = 8.90, 95% CI 3.24-24.42, P < 0.00001).

CONCLUSION

The CD147 positive expression rate was closely related to the clinical characteristics of prostate cancer, but more research is needed to confirm the findings owing to the results of the subgroups.

EMMPRIN/CD147 is an independent prognostic biomarker in cutaneous melanoma

CD147 has been implicated in melanoma invasion and metastasis mainly through increasing metalloproteinase synthesis and regulating VEGF/VEGFR signalling. In this study, the prognostic value of CD147 expression was investigated in a cohort of 196 cutaneous melanomas including 136 consecutive primary malignant melanomas, 30 lymph nodes, 16 in-transit and 14 visceral metastases. A series of 10 normal skin, 10 blue nevi and 10 dermal nevi was used as control. CD147 expression was assessed by immunohistochemistry, and the association of its expression with the clinicopathological characteristics of patients and survival was evaluated using univariate and multivariate statistical analyses. Univariate analysis showed that high CD147 expression was significantly associated with metastatic potential and with a reduced overall survival (P < 0.05 for both) in primary melanoma patients. CD147 expression level was correlated with histological factors which were associated with prognosis: Clark level, ulceration status and more particularly with Breslow index (r = 0.7, P < 10(-8) ). Multivariate analysis retained CD147 expression level and ulceration status as predicting factors for metastasis and overall survival (P < 0.05 for both). CD147 emerges as an important factor in the aggressive behaviour of melanoma and deserves further evaluation as an independent prognostic biomarker.

How, with whom and when: an overview of CD147-mediated regulatory networks influencing matrix metalloproteinase activity

Matrix metalloproteinases (MMPs) comprise a family of 23 zinc-dependent enzymes involved in various pathologic and physiologic processes. In cancer, MMPs contribute to processes from tumour initiation to establishment of distant metastases. Complex signalling and protein transport networks regulate MMP synthesis, cell surface presentation and release. Earlier attempts to disrupt MMP activity in patients have proven to be intolerable and with underwhelming clinical efficacy; thus targeting ancillary proteins that regulate MMP activity may be a useful therapeutic approach. Extracellular matrix metalloproteinase inducer (EMMPRIN) was originally characterized as a factor present on lung cancer cells, which stimulated collagenase (MMP-1) production in fibroblasts. Subsequent studies demonstrated that EMMPRIN was identical with several other protein factors, including basigin (Bsg), all of which are now commonly termed CD147. CD147 modulates the synthesis and activity of soluble and membrane-bound [membrane-type MMPs (MT-MMPs)] in various contexts via homophilic/heterophilic cell interactions, vesicular shedding or cell-autonomous processes. CD147 also participates in inflammation, nutrient and drug transporter activity, microbial pathology and developmental processes. Despite the hundreds of manuscripts demonstrating CD147-mediated MMP regulation, the molecular underpinnings governing this process have not been fully elucidated. The present review summarizes our present knowledge of the complex regulatory systems influencing CD147 biology and provides a framework to understand how CD147 may influence MMP activity.

Upregulation of extracellular matrix metalloproteinase inducer promotes hypoxia-induced epithelial-mesenchymal transition in esophageal cancer

Extracellular matrix metalloproteinase inducer (EMMPRIN) exerts important roles in tumor progression, including angiogenesis, metastasis and therapy resistance. The epithelial‑mesenchymal transition (EMT), which is induced by hypoxia, is an important process in cancer metastasis. However, the association between hypoxia and EMMPRIN remains to be elucidated in esophageal cancer. The expression of EMMPRIN was determined by western blotting and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), and EMT markers were analyzed by western blotting, RT‑qPCR and immunofluoresence. The migration and invasion of cells was investigated by Transwell assay. The results indicated that the expression levels of EMMPRIN in esophageal cancer cells were markedly higher compared with those in normal esophageal cells. EMMPRIN was able to promote esophageal cancer cell migration and invasion under both hypoxic or normoxic conditions, as demonstrated by the migration and invasion assay. The expression levels of E‑cadherin were reduced, and those of snail family zinc finger 1, fibronectin, α‑smooth muscle actin and fibroblast secretory protein 1 increased in esophageal cancer cells following treatment with human recombinant EMMPRIN under hypoxic conditions. The mRNA expression levels of the EMT markers were similar to those of the protein expression levels. Furthermore, the results demonstrated that EMMPRIN was regulated by hypoxia‑inducible factor (HIF)‑1α. These data suggested that EMMPRIN promoted metastasis and the EMT in esophageal cancer cells by regulating HIF-1α.

CD147: regulator of hyaluronan signaling in invasiveness and chemoresistance

Major determinants that influence negative outcome in cancer patients are the abilities of cancer cells to resist current therapies and to invade surrounding host tissue, consequently leading to local and metastatic dissemination. Hyaluronan (HA), a prominent constituent of the tumor microenvironment, not only provides structural support but also interacts with cell surface receptors, especially CD44, that influence cooperative signaling pathways leading to chemoresistance and invasiveness. CD147 (emmprin; basigin) is a member of the Ig superfamily that has also been strongly implicated in chemoresistance and invasiveness. CD147 both regulates HA synthesis and interacts with the HA receptors, CD44, and LYVE-1. Increased CD147 expression induces formation of multiprotein complexes containing CD44 (or LYVE-1) as well as members of the membrane-type matrix metalloproteinase, receptor tyrosine kinase, ABC drug transporter, or monocarboxylate transporter families, which become assembled in specialized lipid raft domains along with CD147 itself. In each case, multivalent HA-receptor interactions are essential for formation or stabilization of the lipid raft complexes and for downstream signaling pathways or transporter activities that are driven by these complexes. We conclude that cooperativity between HA, HA receptors, and CD147 may be a major driver of the interconnected pathways of invasiveness and chemoresistance widely critical to malignancy.

Single-cell RNA-seq: advances and future challenges

Phenotypically identical cells can dramatically vary with respect to behavior during their lifespan and this variation is reflected in their molecular composition such as the transcriptomic landscape. Single-cell transcriptomics using next-generation transcript sequencing (RNA-seq) is now emerging as a powerful tool to profile cell-to-cell variability on a genomic scale. Its application has already greatly impacted our conceptual understanding of diverse biological processes with broad implications for both basic and clinical research. Different single-cell RNA-seq protocols have been introduced and are reviewed here—each one with its own strengths and current limitations. We further provide an overview of the biological questions single-cell RNA-seq has been used to address, the major findings obtained from such studies, and current challenges and expected future developments in this booming field.

Novel regulators of spermatogenesis

Spermatogenesis is a multistep process that supports the production of millions of sperm daily. Understanding of the molecular mechanisms that regulate spermatogenesis has been a major focus for decades. Yet, the regulators involved in different cellular processes of spermatogenesis remain largely unknown. Human diseases that result in defective spermatogenesis have provided hints on the molecular mechanisms regulating this process. In this review, we have summarized recent findings on the function and signaling mechanisms of several genes that are known to be associated with disease or pathological processes, including CFTR, CD147, YWK-II and CT genes, and discuss their potential roles in regulating different processes of spermatogenesis.

Clinical significance of Keap1 and Nrf2 in oral squamous cell carcinoma

Oxidative stress has been reported to play an important role in progression and prognostication in various kinds of cancers. However, the role and clinical significance of oxidative stress markers Keap1 and Nrf2 in oral squamous cell carcinoma (OSCC) has not been elucidated. This study aimed to investigate the correlation of oxidative stress markers Keap1 and Nrf2 expression and pathological features in OSCC by using tissue microarray. Tissue microarrays containing 17 normal oral mucosa, 7 oral epithelial dysplasia and 43 OSCC specimens were studied by immunohistochemistry. The association among these proteins and pathological features were analyzed. Expression of oxidative stress markers Keap1, Nrf2, and antioxidants PPIA, Prdx6, as well as CD147 was found to increase consecutively from normal oral mucosa to OSCC, and the Keap1, Nrf2, PPIA, Prdx6, CD147 expression in OSCC were significantly higher when compared to normal oral mucosa. Expression of Keap1, Nrf2 in tumors was not found to be significantly associated with T category, lymph node metastases, and pathological grade. Furthermore, we checked the relationship among these oxidative stress markers and found that Keap1 was significantly correlated with Nrf2, Prdx6 and CD147. Significant relationship between Nrf2 and Prdx6 was also detected. Finally, we found patients with overexpression of Keap1 and Nrf2 had not significantly worse overall survival by Kaplan-Meier analysis. These findings suggest that ROS markers are associated with carcinogenesis and progression of OSCC, which may have prognostic value and could be regarded as potential therapeutic targets in OSCC.

The role of EMMPRIN expression in ovarian epithelial carcinomas

Purpose: Extracellular matrix metalloproteinase inducer (EMMPRIN) was reported to involve in the invasion and metastasis of malignancies by regulating the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) in stromal and cancer cells. The study aimed to clarify the role of EMMPRIN expression in tumorigenesis and progression of ovarian epithelial carcinomas.

Methods: EMMPRIN siRNA were transfected into ovarian carcinoma cells with the phenotypes and their related molecules examined. EMMPRIN expression was determined in ovarian normal tissue, benign and borderline tumors, and epithelial carcinomas by real-time PCR, western blot, and immunohistochemisty.

Results: EMMPRIN siRNA treatment resulted in a lower growth, G₁ arrest, apoptotic induction, decreased migration, and invasion. The transfectants showed reduced expression of Wnt5a, Akt, p70s6k, Bcl-xL, survivin, VEGF, and MMP-9 than mock and control cells at both mRNA and protein levels. According to real-time PCR and western blot, EMMPRIN mRNA or protein level was higher in ovarian borderline tumor and carcinoma than normal ovary and benign tumors (P &lt; 0.05), and positively correlated with dedifferentiation and FIGO staging (P &lt; 0.05). Immuhistochemically, EMMPRIN expression was positively correlated with FIGO staging, dedifferentiation, Ki-67 expression, the lower cumulative and relapse-free survival rate (P &lt; 0.05).

Conclusions: Upregulated expression of EMMPRIN protein and mRNA might be involved in the pathogenesis, differentiation, and progression of ovarian carcinomas, possibly by modulating cellular events, such as proliferation, cell cycle, apoptosis, migration, and invasion.

CD147, CD44, and the epidermal growth factor receptor (EGFR) signaling pathway cooperate to regulate breast epithelial cell invasiveness

The immunoglobulin superfamily glycoprotein CD147 (emmprin; basigin) is associated with an invasive phenotype in various types of cancers, including malignant breast cancer. We showed recently that up-regulation of CD147 in non-transformed, non-invasive breast epithelial cells is sufficient to induce an invasive phenotype characterized by membrane type-1 matrix metalloproteinase (MT1-MMP)-dependent invadopodia activity (Grass, G. D., Bratoeva, M., and Toole, B. P. (2012) Regulation of invadopodia formation and activity by CD147. J. Cell Sci. 125, 777-788). Here we found that CD147 induces breast epithelial cell invasiveness by promoting epidermal growth factor receptor (EGFR)-Ras-ERK signaling in a manner dependent on hyaluronan-CD44 interaction. Furthermore, CD147 promotes assembly of signaling complexes containing CD147, CD44, and EGFR in lipid raftlike domains. We also found that oncogenic Ras regulates CD147 expression, hyaluronan synthesis, and formation of CD147-CD44-EGFR complexes, thus forming a positive feedback loop that may amplify invasiveness. Last, we showed that malignant breast cancer cells are heterogeneous in their expression of surface-associated CD147 and that high levels of membrane CD147 correlate with cell surface EGFR and CD44 levels, activated EGFR and ERK1, and activated invadopodia. Future studies should evaluate CD147 as a potential therapeutic target and disease stratification marker in breast cancer.

Emmprin and KSHV: new partners in viral cancer pathogenesis

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Emmprin regulates pathogenic elements relevant to virus-associated cancer, including drug resistance and cell migration.

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Kaposi's sarcoma-associated herpesvirus (KSHV) regulates emmprin expression and downstream function.

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Targeting emmprin or its interacting proteins at the cell surface suppresses KSHV-induced pathogenesis in vitro.

Emmprin (CD147; basigin) is a multifunctional glycoprotein expressed at higher levels by cancer cells and stromal cells in the tumor microenvironment. Through direct effects within tumor cells and promotion of tumor–stroma interactions, emmprin participates in induction of tumor cell invasiveness, angiogenesis, metastasis and chemoresistance. Although its contribution to cancer progression has been widely studied, the role of emmprin in viral oncogenesis still remains largely unclear, and only a small body of available literature implicates emmprin-associated mechanisms in viral pathogenesis and tumorigenesis. We summarize these data in this review, focusing on the role of emmprin in pathogenesis associated with the Kaposi sarcoma-associated herpesvirus (KSHV), a common etiology for cancers arising in the setting of immune suppression. We also discuss future directions for mechanistic studies exploring roles for emmprin in viral cancer pathogenesis.

Proteomic analysis reveals that CD147/EMMPRIN confers chemoresistance in cancer stem cell-like cells

Cancer stem cells (CSCs) are a subpopulation of tumor cells that can self-renew, metastasize, and promote cancer recurrence. A comprehensive characterization of the CSC proteome has been hampered due to their scarcity and rapid differentiation. Here, we present a systematic analysis of the cell-surface proteome using a CSC-like cell line derived from MDA-MB453 breast cancer cells, which exhibited a CD44(+) /CD24(-) (where CD is cluster of differentiation) phenotype and chemoresistance. We identified differentially expressed proteins in CSC-like cells, including upregulated plasma membrane proteins such as CD44, CD133, epidermal growth factor receptor (EGFR), CD147, cadherin 1, integrins, and catenin (cadherin-associated protein), beta 1 (CTNNB1), using an in-situ biotinylation approach followed by MS analysis. We examined the role of CD147 in the promotion of CSC growth and survival, and demonstrated that inhibition of CD147 with a monoclonal antibody induced significant inhibition of cell growth. siRNA-mediated silencing of CD147 gene expression restored the sensitivity of CSC-like cells to 5-fluorouracil (5-FU), along with decreasing the expression of thymidylate synthase, p-AKT, and β-catenin, while increasing the expression of p-glycogen synthase kinase (GSK)3β. Increased CD147 expression in the CSC-like cells, as seen by proteomic analysis, and the functional consequences of CD147 overexpression in CSC-like cells suggest that CD147 may be one of the critical cell-surface proteins involved in promoting chemoresistance and survival in CSCs.