Cyclin D1, Id1 and EMT in breast cancer

Characteristics and transcriptional regulators of spontaneous epithelial-mesenchymal transition in genetically unperturbed patient-derived non-spindled breast carcinoma

BACKGROUND

Although tumor cells undergoing epithelial-mesenchymal transition (EMT) typically exhibit spindle morphology in experimental models, such histomorphological evidence of EMT has predominantly been observed in rare primary spindle carcinomas. The characteristics and transcriptional regulators of spontaneous EMT in genetically unperturbed non-spindled carcinomas remain underexplored.

METHODS

We used primary culture combined with RNA sequencing (RNA-seq), single-cell RNA-seq (scRNA-seq), and in situ RNA-seq to explore the characteristics and transcription factors (TFs) associated with potential spontaneous EMT in non-spindled breast carcinoma.

RESULTS

Our primary culture revealed carcinoma cells expressing diverse epithelial-mesenchymal traits, consistent with epithelial-mesenchymal plasticity. Importantly, carcinoma cells undergoing spontaneous EMT did not necessarily exhibit spindle morphology, even when undergoing complete EMT. EMT was a favored process, whereas mesenchymal-epithelial transition appeared to be crucial for secondary tumor growth. Through scRNA-seq, we identified TFs that were sequentially and significantly upregulated as carcinoma cells progressed through the EMT process, which correlated with increasing VIM expression. Once upregulated, the TFs remained active throughout the EMT process. ZEB1 was a key initiator and sustainer of EMT, as indicated by its earliest significant upregulation in the EMT process, its exact correlation with VIM expression, and the reversal of EMT and downregulation of EMT-upregulated TFs upon ZEB1 knockdown. The correlation between ZEB1 and vimentin expression in triple-negative breast cancer and metaplastic breast carcinoma tumor cohorts further highlighted its role. The immediate upregulation of ZEB2 following that of ZEB1, along with the observation that the knockdown of ZEB1 or ZEB2 downregulates both ZEB1 and ZEB2 concomitant with the reversal of EMT, suggests their functional cooperation in EMT. This finding, together with that of a lack of correlation of SNAI1, SNAI2, and TWIST1 expression with the mesenchymal phenotype, indicated EMT-TFs have a context-dependent role in EMT. Upregulation of EMT-related gene signatures during EMT correlated with poor patient outcomes, highlighting the biological importance of the model. Elevated EMT gene signatures and increased ZEB1 and ZEB2 expression in vimentin-positive compared to vimentin-negative carcinoma cells within the corresponding primary tumor tissue confirmed ZEB1 and ZEB2 as intrinsic, instead of microenvironmentally-induced, EMT regulators, and vimentin as an in vivo indicator of EMT.

CONCLUSIONS

Our findings provide insights into the characteristics and transcriptional regulators of spontaneous EMT in primary non-spindled carcinoma.

Glutathione and Xanthine Metabolic Changes in Tamoxifen Resistant Breast Cancer Cell Lines are Mediated by Down-Regulation of GSS and XDH and Correlated to Poor Prognosis

Background: Tamoxifen is commonly used in the treatment of hormonal-positive breast cancer. However, 30%-40% of tumors treated with tamoxifen develop resistance; therefore, an important step to overcome this resistance is to understand the underlying molecular and metabolic mechanisms. In the present work, we used metabolic profiling to determine potential biomarkers of tamoxifen resistance, and gene expression levels of enzymes important to these metabolites and then correlated the expression to the survival of patients receiving tamoxifen. Methods: Tamoxifen-resistant cell lines previously developed and characterized in our laboratory were metabolically profiled with nuclear magnetic resonance spectroscopy (NMR) using cryogenic probe, and the findings were correlated with the expression of genes that encode the key enzymes of the significant metabolites. Moreover, the effect of significantly altered genes on the overall survival of patients was assessed using the Kaplan-Meier plotter web tool. Results: We observed a significant increase in the levels of glutamine, taurine, glutathione, and xanthine, and a significant decrease in the branched-chain amino acids, valine, and isoleucine, as well as glutamate and cysteine in the tamoxifen-resistant cells compared to tamoxifen sensitive cells. Moreover, xanthine dehydrogenase and glutathione synthase gene expression were downregulated, whereas glucose-6-phosphate dehydrogenase was upregulated compared to control. Additionally, increased expression of xanthine dehydrogenase was associated with a better outcome for breast cancer patients. Conclusion: Overall, this study sheds light on metabolic pathways that are dysregulated in tamoxifen-resistant cell lines and the potential role of each of these pathways in the development of resistance.

Fusion Oncogenes in Patients With Locally Advanced or Distant Metastatic Differentiated Thyroid Cancer

CONTEXT

Fusion oncogenes are involved in the underlying pathology of advanced differentiated thyroid cancer (DTC), and even the cause of radioactive iodine (RAI)-refractoriness.

OBJECTIVE

We aimed to investigation between fusion oncogenes and clinicopathological characteristics involving a large-scale cohort of patients with advanced DTC.

METHODS

We collected 278 tumor samples from patients with locally advanced (N1b or T4) or distant metastatic DTC. Targeted next-generation sequencing with a 26-gene ThyroLead panel was performed on these samples.

RESULTS

Fusion oncogenes accounted for 29.86% of the samples (72 rearrangement during transfection (RET) fusions, 7 neurotrophic tropomyosin receptor kinase (NTRK) fusions, 4 anaplastic lymphoma kinase (ALK) fusions) and occurred more frequently in pediatric patients than in their adult counterparts (P = .003, OR 2.411, 95% CI 1.329-4.311) in our cohort. DTCs with fusion oncogenes appeared to have a more advanced American Joint Committee on Cancer (AJCC)_N and AJCC_M stage (P = .0002, OR 15.47, 95% CI 2.54-160.9, and P = .016, OR 2.35, 95% CI 1.18-4.81) than those without. DTCs with fusion oncogenes were associated with pediatric radioactive iodine (RAI) refractoriness compared with those without fusion oncogenes (P = .017, OR 4.85, 95% CI 1.29-15.19). However, in adult DTCs, those with fusion oncogenes were less likely to be associated with RAI refractoriness than those without (P = .029, OR 0.50, 95% CI 0.27-0.95), owing to a high occurrence of the TERT mutation, which was the most prominent genetic risk factor for RAI refractoriness in multivariate logistic regression analysis (P < .001, OR 7.36, 95% CI 3.14-17.27).

CONCLUSION

Fusion oncogenes were more prevalent in pediatric DTCs than in their adult counterparts and were associated with pediatric RAI refractoriness, while in adult DTCs, TERT mutation was the dominant genetic contributor to RAI refractoriness rather than fusion oncogenes.

The Evolving Pathways of the Efficacy of and Resistance to CDK4/6 Inhibitors in Breast Cancer

The approval of cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) in combination with endocrine therapy (ET) has remarkably improved the survival outcomes of patients with advanced hormone receptor-positive (HR+) breast cancer (BC), becoming the new standard of care treatment in these patients. Despite the efficacy of this therapeutic combination, intrinsic and acquired resistance inevitably occurs and represents a major clinical challenge. Several mechanisms associated with resistance to CDK4/6i have been identified, including both cell cycle-related and cell cycle-nonspecific mechanisms. This review discusses new insights underlying the mechanisms of action of CDK4/6i, which are more far-reaching than initially thought, and the currently available evidence of the mechanisms of resistance to CDK4/6i in BC. Finally, it highlights possible treatment strategies to improve CDK4/6i efficacy, summarizing the most relevant clinical data on novel combination therapies involving CDK4/6i.

Identification and validation of the cellular senescence-related molecular subtypes of triple negative breast cancer via integrating bulk and single-cell RNA sequencing data

Patients with triple-negative breast cancer (TNBC) reportedly benefit from immune checkpoint blockade (ICB) therapy. However, the subtype-specific vulnerabilities of ICB in TNBC remain unclear. As the complex interplay between cellular senescence and anti-tumor immunity has been previously discussed, we aimed to identify markers related to cellular senescence that may serve as potential predictors of response to ICB in TNBC. We used three transcriptomic datasets derived from ICB-treated breast cancer samples at both scRNA-seq and bulk-RNA-seq levels to define the subtype-specific vulnerabilities of ICB in TNBC. Differences in the molecular features and immune cell infiltration among the different TNBC subtypes were further explored using two scRNA-seq, three bulk-RNA-seq, and two proteomic datasets. 18 TNBC samples were collected and utilized to verify the association between gene expression and immune cell infiltration by multiplex immunohistochemistry (mIHC). A specific type of cellular senescence was found to be significantly associated with response to ICB in TNBC. We employed the expression of four senescence-related genes, namely CDKN2A, CXCL10, CCND1, and IGF1R, to define a distinct senescence-related classifier using the non-negative matrix factorization approach. Two clusters were identified, namely the senescence-enriching cluster (C1; CDKN2A high CXCL10 high CCND1 low IGF1R low) and proliferating-enriching cluster (C2; CDKN2A low CXCL10 low CCND1 high IGF1R high). Our results indicated that the C1 cluster responds better to ICB and behaves with higher CD8+ T cell infiltration than the C2 cluster. Altogether, in this study, we developed a robust cellular senescence-related classifier of TNBC based on the expression of CDKN2A, CXCL10, CCND1, and IGF1R. This classifier act as a potential predictor of clinical outcomes and response to ICB.

FBXO43 increases CCND1 stability to promote hepatocellular carcinoma cell proliferation and migration

Background and Aims

Abnormal expression of E3 ubiquitin ligase plays an important role in the development and progression of hepatocellular carcinoma (HCC), although the mechanism has remained elusive. This study aimed to investigate the biological function and potential mechanism of FBXO43 in HCC.

Methods

FBXO43 expression in tissues and cells were detected by quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemistry (IHC). The Kaplan-Meier method and Cox regression analysis were used to explore the correlation between the expression level of FBXO43 and the clinical survival. MTT assay, EdU incorporation, colony formation, Transwell, and wound healing assays were performed to evaluate the function of FBXO43 in cell proliferation and migration in vitro. The interaction between FBXO43 and cyclin D1 (CCND1) was assessed by co-immunoprecipitation (Co-IP) assay and in vivo ubiquitination assay.

Results

We found that FBXO43 was upregulated in HCC patient tissues and positively associated with poor clinicopathological features. Meanwhile, HCC patients with high expression of FBXO43 had shorter overall survival (OS) and disease-free survival (DFS). Furthermore, knockdown of FBXO43 inhibited HCC cell proliferation, migration and epithelial-mesenchymal transition (EMT) in HCC cells. Mechanistically, FBXO43 interacted with CCND1 and promoted its stability by polyubiquitination, leading to HCC cell proliferation, migration and EMT. Functional rescue experiments demonstrated that knockdown of CCND1 blocks FBXO43-mediated cell proliferation and metastasis.

Conclusions

FBXO43, as an independent prognostic biomarker, promotes HCC cell proliferation, metastasis and EMT by stability of CCND1, which provides a new potential strategy for HCC treatment by targeting FBXO43-CCND1 axis.

Challenging Endocrine Sensitivity of Hormone Receptor-Positive/HER2-Negative Advanced Breast Cancer with the Combination of Eribulin and Endocrine Therapy: The REVERT Study

BACKGROUND

Luminal advanced breast cancer (ABC) patients eventually progress on endocrine therapy. REVERT aimed to explore whether eribulin could restore endocrine sensitivity in a randomized, non-comparative phase II trial.

METHODS

Aromatase inhibitor (AI)-resistant patients with luminal ABC were randomized 1:1 to receive eribulin +/- AI. Patients were stratified by prior cyclin-dependent kinases 4/6 inhibitor (CDK4/6i) treatment. The primary endpoint was an investigator-assessed overall response rate (ORR) according to RECIST version 1.1 in the eribulin + AI arm. An interim analysis was planned with 11 evaluable patients according to a two-stage Simon design.

RESULTS

Twenty-two patients were enrolled (15 eribulin + AI arm; 7 eribulin arm). The trial was terminated early in March 2021, with eight (36.4%) patients still on treatment. ORR was 26.7% in the eribulin + AI arm (95% CI, 7.8-55.1%; p = 0.0541). In the eribulin arm, two (28.6%) patients had an objective response (95% CI, 3.7-71.0%). The difference between the study arms was not significant (p = 0.918). The addition of AI to eribulin also failed to show improvement in other efficacy endpoints. A significant interaction between the treatment arm and previous CDK4/6i treatment was observed for ORR (p = 0.018) and progression-free survival (p = 0.084). Overall, the toxicity profile was consistent with the known safety profile of eribulin. No treatment-related deaths were reported.

CONCLUSION

Eribulin + AI does not seem to improve outcomes compared with eribulin monotherapy in patients with AI-resistant luminal ABC. This chemo-endocrine approach deserves further investigation after progression to CDK4/6i-based therapy.

MiR-93-5p regulates tumorigenesis and tumor immunity by targeting PD-L1/CCND1 in breast cancer

Background

Challenges in medical care posed by rapid tumor progression, individualized responses to therapy, and the heterogeneous characteristics of breast cancer (BRCA) highlight the urgent need for new treatment strategies, as well as therapeutic and prognostic markers. Accumulating evidence has revealed that microRNAs broadly participate in carcinogenesis, but our understanding of the role of miR-93-5p in BRCA remains limited.

Methods

The prognosis of miR-93-5p, programmed cell death-ligand 1 (PD-L1) and CCND1 were analyzed by datasets. Freshly excised breast cancer tissues (N=33) and adjacent noncancerous tissues (N=18) were collected to detect the expression of CCND1 and PD-L1 by immunohistochemistry (IHC). Quantitative real-time PCR (qRT-PCR) and Western blot were used to test the expression of miR-93-5p, PD-L1 and CCND1 after transfected mimics or inhibitors. Dual-luciferase reporter assay indicates the direct targeting between miR-93-5p and PD-L1.

Results

Bioinformatics analysis demonstrated that miR-93-5p plays differential roles in various tumors, and further verification using qRT-PCR revealed that the expression levels of miR-93-5p were lower in MDA-MB-231 cells than in noncancerous breast cells. In addition, we confirmed that PD-L1 and CCND1 generated mutual effects, and miR-93-5p directly targets the PD-L1/CCND1 signaling pathway to influence their accumulation and distribution in the cell membrane, nucleus, and cytoplasm, mediating tumor progression and immune regulation in BRCA.

Conclusions

Taken together, miR-93-5p could regulate tumorigenesis and tumor immunity by targeting PD-L1/CCND1 in BRCA and our research provides a rationale for therapy with miR-93-5p to overcome immune escape and improve risk stratification.

Identification of hub genes associated with EMT-induced chemoresistance in breast cancer using integrated bioinformatics analysis

Chemoresistance is one of the major challenges in the treatment of breast cancer. Recent evidence suggests that epithelial-to-mesenchymal transition (EMT) plays a critical role in not only metastasis but also in chemoresistance, hence causing tumor relapse. This study aimed to identify the hub genes associated with EMT and chemoresistance in breast cancer affecting patient/clinical survival. Commonly differentially expressed genes (DEGs) during EMT and chemoresistance in breast cancer cells were identified using publicly available datasets, GSE23655, GSE39359, GSE33146 and GSE76540. Hierarchical clustering analysis was utilized to determine the commonly DEGs expression pattern in chemoresistant (CR) breast cancer cells. GSEA revealed that EMT-related genes sets were enriched in the CR samples. Further, we found that EMT-induced breast cancer cells showed overexpression of drug efflux transporters along with resistance to chemotherapeutic drug. Pathway enrichment analysis revealed that the commonly DEGs were enriched in immunological pathways, early endosome, protein dimerization, and proteoglycans in cancer. Further, we identified eight hub genes from the protein-protein interaction (PPI) network. We validated the gene expression levels of the hub genes among TCGA breast cancer samples using UALCAN. Survival analysis for the hub genes was performed using KM plotter, which showed a worse relapse-free survival (RFS) of the hub genes among breast cancer patients. In conclusion, this study identified eight hub genes that play an important role in the pathways underlying EMT-induced chemoresistance in breast cancer and can be used as therapeutic targets after clinical validation.

A new liposomal nanocarrier for co-delivery of gedunin and p-glycoprotein siRNA to target breast cancer stem cells

Gedunin is a secondary metabolite found in neem tree. Since the first discovery of this compound, its bio-active properties have been continuously evaluated. However, the low hydrophobicity of gedunin decreases its bioavailability and pharmacokinetic profile. In the present investigation, a new liposomal nanocarrier for co-delivery of gedunin and P-glycoprotein (P-gp) siRNA [siRNA coated liposomal gedunin (Lipo-Ged-siRNA)] was developed to improve the anti-proliferative activity of gedunin. Characteristics of prepared Lipo-Ged-siRNA demonstrated promising effects. Lipo-Ged-siRNA showed greater anti-proliferative effects (IC₅₀-8.5 µg/mL) followed by pure gedunin (IC₅₀- 40.2 µg/mL) in breast cancer stem cells (bCSCs). Immunofluorescence analysis demonstrated reduced expression of P-gp following exposure to Lipo-Ged-siRNA. Furthermore, Lipo-Ged-siRNA affected the expression of ABCB1, Cyclin D1, Bax, p53, and surviving genes in bCSCs.

CCT5 interacts with cyclin D1 promoting lung adenocarcinoma cell migration and invasion

Cyclin D1 (CCND1) has been identified as a metastatic promoter in various tumors including lung adenocarcinoma (LUAD), a subtype of non small cell lung cancer (NSCLC). The previous observation revealed that CCND1 was upregulated in NSCLC and predicted poor prognosis of LUAD patients. In this study, we examined a chaperonin containing TCP1 subunit 5 (CCT5) protein interacts with CCND1 in LUAD. Immunofluorescence demonstrated the co-localization of CCT5 and CCND1 protein in LUAD cells. CCT5 expression was detected with both immunohistochemistry (IHC) and bioinformatics analyses. Similar with the expression pattern of CCND1, CCT5 displayed a high level in LUAD tissues compared to non cancerous lung specimens. Patients with high CCT5 expression showed a significant shorter overall survival relative to those with low expression level. Furthermore, upregulated CCT5 exhibited significant positive correlation with TNM stage of LUAD patients in both IHC analyses and bioinformatics. Knocking down CCT5 remarkably inhibited LUAD cell migration and invasion in vitro by inactivating PI3K/AKT and its downstream EMT signals, which could abrogated the accelerated migration and invasion caused by CCND1 overexpression. In summary, our study discovered a highly expressed protein CCT5 in LUAD which interacted with CCND1 and promoted migration and invasion of LUAD cells by positively moderating PI3K/AKT-induced EMT pathway.

Breast Cancer Resistance to Cyclin-Dependent Kinases 4/6 Inhibitors: Intricacy of the Molecular Mechanisms

Breast cancer is a common malignant tumor in women, with a highest incidence and mortality among all of the female malignant tumors. Notably, targeted therapy has achieved impressive success in the treatment of breast cancer. As one class of the anti-tumor targeted therapeutics, Cyclin-Dependent Kinases 4/6CDK4/6inhibitors have shown good clinical activity in treating breast cancer. Nevertheless, despite the promising clinical outcomes, intrinsic or acquired resistance to CDK4/6 inhibitors has limited the benefits of this novel target therapy. In the present review, we provide an overview of the currently known molecular mechanisms of resistance to CDK4/6 inhibitors, and discuss the potential strategies to overcoming drug resistance improving the outcomes for breast cancer patients treated with CDK4/6 inhibitors.

Human-derived osteoblast-like cells and pericyte-like cells induce distinct metastatic phenotypes in primary breast cancer cells

Approximately 70% of advanced breast cancer patients will develop bone metastases, which accounts for ∼90% of cancer-related mortality. Breast cancer circulating tumor cells (CTCs) establish metastatic tumors in the bone after a close interaction with local bone marrow cells including pericytes and osteoblasts, both related to resident mesenchymal stem/stromal cells (BM-MSCs) progenitors. In vitro recapitulation of the critical cellular players of the bone microenvironment and infiltrating CTCs could provide new insights into their cross-talk during the metastatic cascade, helping in the development of novel therapeutic strategies. Human BM-MSCs were isolated and fractionated according to CD146 presence. CD146+ cells were utilized as pericyte-like cells (PLCs) given the high expression of the marker in perivascular cells, while CD146- cells were induced into an osteogenic phenotype generating osteoblast-like cells (OLCs). Transwell migration assays were performed to establish whether primary breast cancer cells (3384T) were attracted to OLC. Furthermore, proliferation of 3384T breast cancer cells was assessed in the presence of PLC- and OLC-derived conditioned media. Additionally, conditioned media cultures as well as transwell co-cultures of each OLCs and PLCs were performed with 3384T breast cancer cells for gene expression interrogation assessing their induced transcriptional changes with an emphasis on metastatic potential. PLC as well as their conditioned media increased motility and invasion potential of 3384T breast cancer cells, while OLC induced a dormant phenotype, downregulating invasiveness markers related with migration and proliferation. Altogether, these results indicate that PLC distinctively drive 3384T cancer cells to an invasive and migratory phenotype, while OLC induce a quiescence state, thus recapitulating the different phases of the in vivo bone metastatic process. These data show that phenotypic responses from metastasizing cancer cells are influenced by neighboring cells at the bone metastatic niche during the establishment of secondary metastatic tumors.

MicroRNA-374b inhibits breast cancer progression through regulating CCND1 and TGFA genes

Emerging evidence indicates that microRNAs (miRNAs) play a critical role in breast cancer development. We recently reported that a higher expression of miR-374b in tumor tissues was associated with a better disease-free survival of triple-negative breast cancer (TNBC). However, the functional significance and molecular mechanisms underlying the role of miR-374b in breast cancer are largely unknown. In this current study, we evaluated the biological functions and potential mechanisms of miR-374b in both TNBC and non-TNBC. We found that miR-374b was significantly downregulated in breast cancer tissues, compared to adjacent tissues. MiR-374b levels were also lower in breast cancer cell lines, as compared to breast epithelial cells. In vitro and in vivo studies demonstrated that miR-374b modulates the malignant behavior of breast cancer cells, such as cell proliferation in 2D and 3D, cell invasion ability, colony-forming ability and tumor growth in mice. By using bioinformatics tools, we predicted that miR-374b plays a role in breast cancer cells through negatively regulating cyclin D1 (CCND1) and transforming growth factor alpha (TGFA). We further confirmed that CCND1 and TGFA contribute to the malignant behavior of breast cancer cells in vitro and in vivo. Our rescue experiments showed that overexpressing CCND1 or TGFA reverses the phenotypes caused by miR-374b overexpression. Taken together, our studies suggest that miR-374b modulates malignant behavior of breast cancer cells by negatively regulating CCND1 and TGFA genes. The newly identified miR-374b-mediated CCND1 and TGFA gene silencing may facilitate a better understanding of the molecular mechanisms of breast cancer progression.

Ultrasound-Targeted Microbubble Destruction Mediated si-CyclinD1 Inhibits the Development of Hepatocellular Carcinoma via Suppression of PI3K/AKT Signaling Pathway

Background and Aim

In our study, we aimed to investigate the effect of ultrasound-targeted microbubble destruction (UTMD)mediated si-CyclinD1 (CCND1) on the growth of hepatocellular carcinoma (HCC) cells.

Patients and Methods

Bioinformatics analysis was performed to detect the difference of CCND1 expression of HCC and normal liver tissues. After treatment with UTMDmediated si-CCND1, the growth and apoptosis of HepG2 cells were detected by flow cytometry, MTT, EdU staining, colony formation assay, Hoechst 33,258 staining and Western blot analysis. The growth of HepG2 cells in vivo was also studied via xenograft tumor in nude mice.

Results

CCND1 was highly expressed in HCC tissues and HCC cell lines. UTMDmediated si-CCND1 could inhibit the growth of HepG2 cells and promote apoptosis via suppression of the PI3K/AKT signaling pathway. UTMDmediated si-CCND1 could also suppress the growth of HepG2 cells in vivo.

Conclusion

Our study provided evidence that UTMDmediated si-CCND1 could inhibit the growth of HepG2 cells and promote apoptosis via suppression of the PI3K/AKT signaling pathway.

Id Proteins Promote a Cancer Stem Cell Phenotype in Mouse Models of Triple Negative Breast Cancer via Negative Regulation of Robo1

Breast cancers display phenotypic and functional heterogeneity and several lines of evidence support the existence of cancer stem cells (CSCs) in certain breast cancers, a minor population of cells capable of tumor initiation and metastatic dissemination. Identifying factors that regulate the CSC phenotype is therefore important for developing strategies to treat metastatic disease. The Inhibitor of Differentiation Protein 1 (Id1) and its closely related family member Inhibitor of Differentiation 3 (Id3) (collectively termed Id) are expressed by a diversity of stem cells and are required for metastatic dissemination in experimental models of breast cancer. In this study, we show that ID1 is expressed in rare neoplastic cells within ER-negative breast cancers. To address the function of Id1 expressing cells within tumors, we developed independent murine models of Triple Negative Breast Cancer (TNBC) in which a genetic reporter permitted the prospective isolation of Id1+ cells. Id1+ cells are enriched for self-renewal in tumorsphere assays in vitro and for tumor initiation in vivo. Conversely, depletion of Id1 and Id3 in the 4T1 murine model of TNBC demonstrates that Id1/3 are required for cell proliferation and self-renewal in vitro, as well as primary tumor growth and metastatic colonization of the lung in vivo. Using combined bioinformatic analysis, we have defined a novel mechanism of Id protein function via negative regulation of the Roundabout Axon Guidance Receptor Homolog 1 (Robo1) leading to activation of a Myc transcriptional programme.

Effects of tumor-specific CAP1 expression and body constitution on clinical outcomes in patients with early breast cancer

Background

Obesity induces molecular changes that may favor tumor progression and metastatic spread, leading to impaired survival outcomes in breast cancer. Adenylate cyclase-associated protein 1 (CAP1), an actin regulatory protein and functional receptor for the obesity-associated adipokine resistin, has been implicated with inferior cancer prognosis. Here, the objective was to investigate the interplay between body composition and CAP1 tumor expression regarding breast cancer outcome through long-term survival analyses.

Methods

Among 718 women with primary invasive breast cancer within the large population-based prospective Malmö Diet and Cancer Study, tumor-specific CAP1 levels were assessed following thorough antibody validation and immunohistochemical staining of tumor tissue microarrays. Antibody specificity and functional application validity were determined by CAP1 gene silencing, qRT-PCR, Western immunoblotting, and cell microarray immunostaining. Kaplan-Meier and multivariable Cox proportional hazard models were used to assess survival differences in terms of breast cancer-specific survival (BCSS) and overall survival (OS) according to body composition and CAP1 expression.

Results

Study participants were followed for up to 25 years (median 10.9 years), during which 239 deaths were observed. Patients with low CAP1 tumor expression were older at diagnosis, displayed anthropometric measurements indicating a higher adiposity status (wider waist and hip, higher body mass index and body fat percentage), and were more prone to have unfavorable tumor characteristics (higher histological grade, higher Ki67, and estrogen receptor (ER) negativity). Overall, patients with CAP1-low tumors had impaired BCSS (adjusted hazard ratio: HR_adj = 0.52, 95% CI 0.31–0.88) and OS (HR_adj = 0.64, 95% CI 0.44–0.92) compared with patients having high CAP1 tumor expression. Further, analyses stratified according to different anthropometric measures or ER status showed that the CAP1-associated survival outcomes were most pronounced among patients with low adiposity status or ER-positive disease.

Conclusions

Low CAP1 tumor expression was associated with higher body fatness and worse survival outcomes in breast cancer patients with effect modification by adiposity and ER status. CAP1 could be a novel marker for poorer survival outcome in leaner or ER-positive breast cancer patients, highlighting the need for considering body constitution in clinical decision making.

Fangjihuangqi Decoction inhibits MDA-MB-231 cell invasion in vitro and decreases tumor growth and metastasis in triple-negative breast cancer xenografts tumor zebrafish model

Triple-negative breast cancer (TNBC) is a basal-like cancer which is considered to be more intrusive, have a poorer prognosis and chemoresistance. TNBC is characterized by the presence of epithelial to mesenchymal transition (EMT) that plays a major role in the progression of the cancer. In the present study, we first use a classic prescription of Chinese medicine Fangjihuangqi Decoction to treat TGFβ1-induced MDA-MB-231 cells in vitro. Our data showed that TGFβ1-induced MDA-MB-231 cell morphology change, promoted MDA-MB 231 invasion, increased Vimentin expression, and decreased E-cadherin expression. Further, Fangjihuangqi Decoction-medicated serum (FHS) treated both MDA-MB 231 cells and TGFβ1-induced MDA-MB-231 cells. Results showed that Fangjihuangqi Decoction could inhibit cell proliferation, reduce cell invasion, increase E-cadherin expression, and decrease EMT markers. Secondly, we established a xenograft tumor zebrafish model to assess Fangjihuangqi Decoction inhibition of cancer cell proliferation and invasion. Our results indicated that Fangjihuangqi Decoction could inhibit tumor growth, restrain the sprouts number of tumor neovascularization, and reduce the length of tumor neoplastic lymphatics by increasing E-cadherin expression and decreasing EMT markers in TNBC xenograft tumor zebrafish model. Overall, our studies provide evidences that Fangjihuangqi Decoction could inhibit TNBC, reverse EMT, and contribute to antimetastasis by increasing E-cadherin expression and decreasing EMT markers, which provide an experimental basis for clinical application of Fangjihuangqi Decoction on TNBC treatment.

Inhibitor of Differentiation 1 (Id1) in Cancer and Cancer Therapy

The inhibitor of DNA binding (Id) proteins are regulators of cell cycle and cell differentiation. Of all Id family proteins, Id1 is mostly linked to tumorigenesis, cellular senescence as well as cell proliferation and survival. Id1 is a stem cell-like gene more than a classical oncogene. Id1 is overexpressed in numerous types of cancers and exerts its promotion effect to these tumors through different pathways. Briefly, Id1 was found significantly correlated with EMT-related proteins, K-Ras signaling, EGFR signaling, BMP signaling, PI3K/Akt signaling, WNT and SHH signaling, c-Myc signaling, STAT3 signaling, RK1/2 MAPK/Egr1 pathway and TGF-β pathway, etc. Id1 has potent effect on facilitating tumorous angiogenesis and metastasis. Moreover, high expression of Id1 plays a facilitating role in the development of drug resistance, including chemoresistance, radiation resistance and resistance to drugs targeting angiogenesis. However, controversial results were also obtained. Overall, Id1 represent a promising target of anti-tumor therapeutics based on its potent promotion effect to cancer. Numerous drugs were found exerting their anti-tumor function through Id1-related signaling pathways, such as fucoidan, berberine, tetramethylpyrazine, crizotinib, cannabidiol and vinblastine.

AMOT130 drives BMP-SMAD signaling at the apical membrane in polarized cells

The large isoform of the transmembrane protein angiomotin (AMOT130) controls cell proliferation and migration of many cell types. AMOT130 associates to the actin cytoskeleton and regulates tight-junction maintenance and signaling often via endosomal uptake of polarity proteins at tight junctions. AMOT130 is highly polarized and present only at the apical side of polarized cells. Here we show that bone morphogenetic protein (BMP) growth factor signaling and AMOT function are interlinked in apical-basal polarized cells. BMP6 controls AMOT internalization and endosomal trafficking in epithelial cells. AMOT130 interacts with the BMP receptor BMPR2 and facilitates SMAD activation and target gene expression. We further demonstrate that this effect of AMOT on BMP-SMAD signaling is dependent on endocytosis and specific to the apical side of polarized epithelial and endothelial cells. Knockdown of AMOT reduces SMAD signaling only from the apical side of polarized cells, while basolateral BMP-SMAD signaling is unaffected. This allows for the first time interference with BMP signaling in a polarized manner and identifies AMOT130 as a novel BMP signaling regulator.

Overexpressed lncRNA GATA6-AS1 Inhibits LNM and EMT via FZD4 through the Wnt/β-Catenin Signaling Pathway in GC

Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Accumulating evidence reveals the significance of long non-coding RNAs (lncRNAs) in various cancers. The current study aimed to evaluate the role of GATA6 antisense RNA 1 (GATA6-AS1) in the epithelial-mesenchymal transition (EMT) and lymph node metastasis (LNM) in GC. GC-related microarray datasets were initially retrieved from the GEO with differentially expressed lncRNAs screened, followed by evaluation of the regulatory relationship between Frizzled 4 (FZD4) and GATA6-AS1. The detailed regulatory mechanism by which GATA6-AS1 influences the Wnt/β-catenin signaling pathway and GC cell biological behaviors was investigated by treating SGC7901 cells with overexpressed GATA6-AS1, specific antisense oligonucleotide against GATA6-AS1, and lithium chloride (LiCl; activator of the Wnt/β-catenin signaling pathway). Finally, xenograft nude mice were used to assay tumor growth and LNM in vivo. GATA6-AS1 was poorly expressed, but FZD4 was highly expressed in GC tissues and cells. Elevated GATA6-AS1 reduced FZD4 expression by recruiting enhancer of zeste homolog 2 (EZH2) and trimethylation at lysine 27 of histone H3 (H3K27me3) to the FZD4 promoter region via the inactivated Wnt/β-catenin signaling pathway, whereby cell invasion, migration, and proliferation, tumor growth, and LNM in nude mice were reduced. Taken together, overexpressed GATA6-AS1 downregulated the expression of FZD4 to inactivate the Wnt/β-catenin signaling pathway, which ultimately inhibited GC progression.

Prognostic Significance of Cyclin D1 Expression in Renal Cell Carcinoma: a Systematic Review and Meta-analysis

Previous studies indicated that cyclin D1 shown the potential as a tumor biomarker. However, the prognostic value of cyclin D1 in renal cell carcinoma (RCC) remains controversial. This study investigated the correlation of cyclin D1 expression with the prognostic and clinicopathological features in RCC patients. We systematically searched the database of PubMed, Embase, Cochrane, and Web of Science updated on November 26, 2017. Eighteen studies with 2282 patients satisfied the inclusion criteria. Results demonstrated that cyclin D1 overexpression in RCC showed significant favorable prognostic impact on disease-free survival (DFS) (HR 0.57, 95% CI: 0.43-0.74) and disease-specific survival (DSS) (HR 0.59, 95% CI 0.41-0.85) without significant heterogeneity. In subgroup of clear cell RCC, the prognostic effect on DFS was robust and the pooled HR was 0.39 (95% CI: 0.27-0.57). However, no association between overall survival (OS) and cyclin D1 expression was observed. Stratified analysis in DFS studies by sample size, staining patterns race and metastasis status showed similar results. Otherwise, cyclin D1 overexpression predicted a reduced prevalence of high TNM stage (T3 + T4) (OR 0.63, 95% CI: 0.40-0.99), high-grade tumor (G3 + G4) (OR 0.51, 95% CI: 0.31-0.81) and large tumor size (OR 0.35, 95% CI: 0.19-0.62). Our meta-analysis indicated that cyclin D1 overexpression could predict the favorable prognosis in patients with RCC.

Molecular mechanisms of resistance to CDK4/6 inhibitors in breast cancer: A review

Deregulation of the cyclin D-CDK4/6-INK4-RB pathway leading to uncontrolled cell proliferation, is frequently observed in breast cancer. Currently, three selective CDK4/6 inhibitors have been FDA approved: palbociclib, ribociclib and abemaciclib. Despite promising clinical outcomes, intrinsic or acquired resistance to CDK4/6 inhibitors has limited the success of these treatments; therefore, the development of various strategies to overcome this resistance is of great importance. We highlight the various mechanisms that are directly or indirectly responsible for resistance to CDK4/6 inhibitors, categorizing them into two broad groups; cell cycle-specific mechanisms and cell cycle-nonspecific mechanisms. Elucidation of the diverse mechanisms through which resistance to CDK4/6 inhibitors occurs, may aid in the design of novel therapeutic strategies to improve patient outcomes. This review summarizes the currently available knowledge regarding mechanisms of resistance to CDK4/6 inhibitors, and possible therapeutic strategies that may overcome this resistance as well.

The number of titrated microRNA species dictates ceRNA regulation

microRNAs (miRNAs) play key roles in cancer, but their propensity to couple their targets as competing endogenous RNAs (ceRNAs) has only recently emerged. Multiple models have studied ceRNA regulation, but these models did not account for the effects of co-regulation by miRNAs with many targets. We modeled ceRNA and simulated its effects using established parameters for miRNA/mRNA interaction kinetics while accounting for co-regulation by multiple miRNAs with many targets. Our simulations suggested that co-regulation by many miRNA species is more likely to produce physiologically relevant context-independent couplings. To test this, we studied the overlap of inferred ceRNA networks from four tumor contexts-our proposed pan-cancer ceRNA interactome (PCI). PCI was composed of interactions between genes that were co-regulated by nearly three-times as many miRNAs as other inferred ceRNA interactions. Evidence from expression-profiling datasets suggested that PCI interactions are predictive of gene expression in 12 independent tumor- and non-tumor contexts. Biochemical assays confirmed ceRNA couplings for two PCI subnetworks, including oncogenes CCND1, HIF1A and HMGA2, and tumor suppressors PTEN, RB1 and TP53. Our results suggest that PCI is enriched for context-independent interactions that are coupled by many miRNA species and are more likely to be context independent.

Extracellular vesicles produced in B cells deliver tumor suppressor miR-335 to breast cancer cells disrupting oncogenic programming in vitro and in vivo

The successful implementation of miRNA (miR) therapies in humans will ultimately rely on the use of vehicles with improved cellular delivery capability. Here we tested a new system that leverages extracellular vesicles (EVs) laden with a tumor suppressor miRNA (miR-335) produced in B cells by plasmid DNA induction (iEVs). We demonstrate that iEVs-335 efficiently and durably restored the endogenous miR-335 pool in human triple negative breast cancer cells, downregulated the expression of the miR-335 target gene SOX4 transcription factor, and markedly inhibited tumor growth in vivo. Remarkably, iEVs-335 mediated transcriptional effects that persisted in tumors after 60 days post orthotopic implantation. Genome-wide RNASeq analysis of cancer cells treated in vitro with iEVs-335 showed the regulation of a discrete number of genes only, without broad transcriptome perturbations. This new technology may be ideally suited for therapies aimed to restore tumor suppressor miRNAs in cancer cells, disrupting the oncogenic program established after escape from miRNA control.

A genomic ruler to assess oncogenic transition between breast tumor and stroma

Background

Cancers induce gene expression alterations in stroma surrounding tumors that supports cancer progression. However, it is actually not at all known the extent of altered stromal gene expression enacted by tumors nor the extent to which altered stromal gene expression penetrates the stromal tissue. Presently, post-surgical “tumor-free” stromal tissue is determined to be cancer-free based on solely on morphological normality—a criteria that has not changed in more than 100 years despite the existence of sophisticated gene expression data to the contrary. We therefore investigated the extent to which breast tumors alter stromal gene expression in three dimensions in women undergoing mastectomy with the intent of providing a genomic determination for development of future risk of recurrence criteria, and to inform the need for adjuvant full-breast irradiation.

Methods and findings

Genome-wide gene expression changes were determined in histopathologically normal breast tissue in 33 women undergoing mastectomy for stage II and III primary invasive ductal carcinoma at serial distances in three dimensions from the tumor. Gene expression was determined by genome-wide mRNA analysis and subjected to metagene mRNA characterization. Tumor-like gene expression signatures in stroma were identified that surprisingly transitioned to a plastic, normalizing homeostatic signature with distance from tumor. Stroma closest to tumor displayed a pronounced tumor-like signature enriched in cancer-promoting pathways involved in disruption of basement membrane, cell migration and invasion, WNT signaling and angiogenesis. By 2 cm from tumor in all dimensions, stromal tissues were in transition, displaying homeostatic and tumor suppressing gene activity, while also expressing cancer supporting pathways.

Conclusions

The dynamics of gene expression in the post-tumor breast stroma likely co-determines disease outcome: reversion to normality or transition to transformation in morphologically normal tissue. Our stromal genomic signature may be important for personalizing surgical and adjuvant therapeutic decisions and risk of recurrence.

Epigenetic regulation of ID4 in breast cancer: tumor suppressor or oncogene?

Background

Inhibitor of differentiation protein 4 (ID4) is a dominant negative regulator of the basic helix-loop-helix (bHLH) family of transcription factors. During tumorigenesis, ID4 may act as a tumor suppressor or as an oncogene in different tumor types. However, the role of ID4 in breast cancer is not clear where both an oncogenic and a tumor suppressor function have been attributed. Here, we hypothesize that ID4 behaves as both, but its role in breast differs according to the estrogen receptor (ER) status of the tumor.

Methods

ID4 expression was retrieved from TCGA database using UCSC Xena. Association between overall survival (OS) and ID4 was assessed using Kaplan–Meier plotter. Correlation between methylation and expression was analyzed using the MEXPRESS tool. In vitro experiments involved ectopic expression of ID4 in MCF-7, T47D, and MDA-MB231 breast cancer cell lines. Migration and colony formation capacity were assessed after transfection treatments. Gene expression was analyzed by ddPCR and methylation by MSP, MS-MLPA, or ddMSP.

Results

Data mining analysis revealed that ID4 expression is significantly lower in ER+ tumors with respect to ER− tumors or normal tissue. We also demonstrate that ID4 is significantly methylated in ER+ tumors. Kaplan–Meier analysis indicated that low ID4 expression levels were associated with poor overall survival in patients with ER+ tumors. In silico expression analysis indicated that ID4 was associated with the expression of key genes of the ER pathway only in ER+ tumors. In vitro experiments revealed that ID4 overexpression in ER+ cell lines resulted in decreased migration capacity and reduced number of colonies. ID4 overexpression induced a reduction in ER levels in ER+ cell lines, while estrogen deprivation with fulvestrant did not induce changes neither in ID4 methylation nor in ID4 expression.

Conclusions

We propose that ID4 is frequently silenced by promoter methylation in ER+ breast cancers and functions as a tumor suppressor gene in these tumors, probably due to its interaction with key genes of the ER pathway. Our present study contributes to the knowledge of the role of ID4 in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0542-8) contains supplementary material, which is available to authorized users.

Knockdown of POLDIP2 suppresses tumor growth and invasion capacity and is linked to unfavorable transformation ability and metastatic feature in non-small cell lung cancer

The main problem in the treatment of non-small cell lung cancer (NSCLC) is metastasis. Epithelial-mesenchymal transition (EMT) is known as the critical signaling in tumor progression, metastasis, and also the drug resistance. In this study, we reported a novel gene Polymerase delta-interacting protein 2 (POLDIP2) was downregulated in NSCLC tissues and first demonstrated that overexpression of POLDIP2 increased the anchorage-independent growth (AIG) and invasiveness of H1299 cells. In addition, we examined that knockdown of POLDIP2 in H1299 and A549 cells reduced tumorigenicity and metastatic capacity in vitro and also in vivo. Moreover, downregulation of the cell proliferation marker cyclin D1 and EMT markers CDH2, Slug, and Twist was showed in H1299 cells by POLDIP2 knockdown, suggesting that the inhibition of malignancy was affected by modulating key genes for tumor growth and invasiveness. Taken together, our study is the first study that demonstrated that POLDIP2 gene was function as an oncogene in NSCLC and implied the oncogenic ability might be through promoting cell proliferation or EMT.

3D FISH to analyse gene domain-specific chromatin re-modeling in human cancer cell lines

Fluorescence in situ hybridization (FISH) is a common technique used to label DNA and/or RNA for detection of a genomic region of interest. However, the technique can be challenging, in particular when applied to single genes in human cancer cells. Here, we provide a step-by-step protocol for analysis of short (35 kb-300 kb) genomic regions in three dimensions (3D). We discuss the experimental design and provide practical considerations for 3D imaging and data analysis to determine chromatin folding. We demonstrate that 3D FISH using BACs (Bacterial Artificial Chromosomes) or fosmids can provide detailed information of the architecture of gene domains. More specifically, we show that mapping of specific chromatin landscapes informs on changes associated with estrogen stimulated gene activity in human breast cancer cell lines.

Propolin C Inhibited Migration and Invasion via Suppression of EGFR-Mediated Epithelial-to-Mesenchymal Transition in Human Lung Cancer Cells

Controlling lung cancer cell migration and invasion via epithelial-to-mesenchymal transition (EMT) through the regulation of epidermal growth factor receptor (EGFR) signaling pathway has been demonstrated. Searching biological active phytochemicals to repress EGFR-regulated EMT might prevent lung cancer progression. Propolis has been used as folk medicine in many countries and possesses anti-inflammatory, antioxidant, and anticancer activities. In this study, the antimigration and anti-invasion activities of propolin C, a c-prenylflavanone from Taiwanese propolis, were investigated on EGFR-regulated EMT signaling pathway. Cell migration and invasion activities were dose-dependently suppressed by noncytotoxic concentration of propolin C. Downregulations of vimentin and snail as well as upregulation of E-cadherin expressions were through the inhibition of EGFR-mediated phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinase (ERK) signaling pathway in propolin C-treated cells. In addition, EGF-induced migration and invasion were suppressed by propolin C-treated A549 lung cancer cells. No significant differences in E-cadherin expression were observed in EGF-stimulated cells. Interestingly, EGF-induced expressions of vimentin, snail, and slug were suppressed through the inhibition of PI3K/Akt and ERK signaling pathway in propolin C-treated cells. Inhibition of cell migration and invasion by propolin C was through the inhibition of EGF/EGFR-mediated signaling pathway, followed by EMT suppression in lung cancer.

TMPRSS4 induces invasion and proliferation of prostate cancer cells through induction of Slug and cyclin D1

TMPRSS4 is a novel type II transmembrane serine protease found at the cell surface that is highly expressed in pancreatic, colon, and other cancer tissues. Previously, we demonstrated that TMPRSS4 mediates tumor cell invasion, migration, and metastasis. We also found that TMPRSS4 activates the transcription factor activating protein-1 (AP-1) to induce cancer cell invasion. Here, we explored TMPRSS4-mediated cellular functions and the underlying mechanisms. TMPRSS4 induced Slug, an epithelial-mesenchymal transition (EMT)-inducing transcription factor, and cyclin D1 through activation of AP-1, composed of c-Jun and activating transcription factor (ATF)-2, which resulted in enhanced invasion and proliferation of PC3 prostate cancer cells. In PC3 cells, not only c-Jun but also Slug was required for TMPRSS4-mediated proliferation and invasion. Interestingly, Slug induced phosphorylation of c-Jun and ATF-2 to activate AP-1 through upregulation of Axl, establishing a positive feedback loop between Slug and AP-1, and thus induced cyclin D1, leading to enhanced proliferation. Using data from The Cancer Genome Atlas, we found that Slug expression positively correlated with that of c-Jun and cyclin D1 in human prostate cancers. Expression of Slug was positively correlated with that of cyclin D1 in various cancer cell lines, whereas expression of other EMT-inducing transcription factors was not. This study demonstrates that TMPRSS4 modulates both invasion and proliferation via Slug and cyclin D1, which is a previously unrecognized pathway that may regulate metastasis and cancer progression.

The expression of VE-cadherin in breast cancer cells modulates cell dynamics as a function of tumor differentiation and promotes tumor-endothelial cell interactions

The cadherin switch has profound consequences on cancer invasion and metastasis. The endothelial-specific vascular endothelial cadherin (VE-cadherin) has been demonstrated in diverse cancer types including breast cancer and is supposed to modulate tumor progression and metastasis, but underlying mechanisms need to be better understood. First, we evaluated VE-cadherin expression by tissue microarray in 392 cases of breast cancer tumors and found a diverse expression and distribution of VE-cadherin. Experimental expression of fluorescence-tagged VE-cadherin (VE-EGFP) in undifferentiated, fibroblastoid and E-cadherin-negative MDA-231 (MDA-VE-EGFP) as well as in differentiated E-cadherin-positive MCF-7 human breast cancer cell lines (MCF-VE-EGFP), respectively, displayed differentiation-dependent functional differences. VE-EGFP expression reversed the fibroblastoid MDA-231 cells to an epithelial-like phenotype accompanied by increased β-catenin expression, actin and vimentin remodeling, increased cell spreading and barrier function and a reduced migration ability due to formation of VE-cadherin-mediated cell junctions. The effects were largely absent in both MDA-VE-EGFP and in control MCF-EGFP cell lines. However, MCF-7 cells displayed a VE-cadherin-independent planar cell polarity and directed cell migration that both developed in MDA-231 only after VE-EGFP expression. Furthermore, VE-cadherin expression had no effect on tumor cell proliferation in monocultures while co-culturing with endothelial cells enhanced tumor cell proliferation due to integration of the tumor cells into monolayer where they form VE-cadherin-mediated cell contacts with the endothelium. We propose an interactive VE-cadherin-based crosstalk that might activate proliferation-promoting signals. Together, our study shows a VE-cadherin-mediated cell dynamics and an endothelial-dependent proliferation in a differentiation-dependent manner.

CDC27 Induces Metastasis and Invasion in Colorectal Cancer via the Promotion of Epithelial-To-Mesenchymal Transition

Distant metastasis is the primary cause of cancer-related death among patients with colorectal cancer (CRC), and the discovery of novel therapeutic targets by further exploring the molecular mechanisms of CRC metastasis is therefore urgently needed. We previously illustrated that CDC27 overexpression promoted proliferation in CRC, but no studies have emphasized the role of CDC27 in cancer metastasis thus far. Our previous data indicated that the expression of CDC27 was significantly associated with distant metastasis in patient tissues, and therefore, in this study, we focused on the investigation of the potential mechanisms of CDC27 in CRC metastasis. The results revealed that CDC27 promoted the metastasis, invasion and sphere-formation capacity of DLD1 cells, but that the inhibition of CDC27 in HCT116 cells suppressed metastasis both in vitro and in vivo. Mechanistic analyses revealed that CDC27 promoted epithelial-to-mesenchymal transition (EMT), as demonstrated by the reduced expression of the epithelial markers ZO-1 and E-cadherin and the enhanced expression of the mesenchymal markers ZEB1 and Snail in HCT116 and DLD1 cells. Further mechanistic investigation indicated that CDC27 promoted metastasis and sphere-formation capacity in an ID1-dependent manner. In conclusion, we first demonstrated the role of CDC27 in cancer metastasis and showed that CDC27 may serve as a promising therapeutic target for CRC.

Rapid Breast Cancer Disease Progression Following Cyclin Dependent Kinase 4 and 6 Inhibitor Discontinuation

Background: CDK 4 and 6 inhibitors (CDK4/6i), which arrest unregulated cancer cell proliferation, show clinical efficacy in breast cancer. Unexpectedly, a patient treated on a CDK4/6i-based trial, as first-line therapy in metastatic breast cancer, developed rapid disease progression following discontinuation of study drug while receiving standard second-line therapy off trial. We thus sought to expand this observation within a population of patients treated similarly at The University of Texas MD Anderson Cancer Center.

Methods: Using an IRB-approved protocol, 4 patients previously enrolled on CDK4/6i trials were analyzed for outcomes after discontinuing study drug. These patients were treated on a randomized trial of first-line endocrine therapy +/- a CDK4/6i. Rapid disease progression was defined as progression occurring within 4 months of CDK4/6i discontinuation.

Results: In total, 4 patients developed rapid disease progression and died; 2 of whom died within 6 months of CDK4/6i discontinuation.

Conclusion: This case series suggests a potential for rapid disease progression following CDK4/6i discontinuation. However, the clinical course following progression must be validated in large CDK4/6i clinical trials and standard-of-care cohorts. If confirmed, such observations may alter the algorithm for subsequent therapy in patients with disease progression on CDK4/6i. Nevertheless, the need remains to define a mechanistic basis for this rapid progression and formulate alternative therapeutic strategies.

Cyclin D1 Gene Silencing Promotes IL-1β-Induced Apoptosis in Rat Chondrocytes

This study investigated the effects of cyclin D1 gene silencing on cell proliferation and apoptosis of interleukin-1β (IL-1β)-induced osteoarthritis (OA) chondrocytes. Chondrocytes from healthy sprague-dawley rats were divided into blank, OA model (chondrocytes underwent IL-1β inducement), OA trial (chondrocytes underwent IL-1β inducement with cyclin D1-shRNA treatment), and negative control (NC; chondrocytes underwent IL-1β inducement and control-shRNA treatment) groups. Cell proliferation was assessed by CCK-8 assay, and cell cycle and apoptosis by flow cytometry. qRT-PCR and Western blotting were performed to detect cyclin D1 and apoptosis-related factors expression levels. Chondrocyte proliferation increased after 72-96 h after incubation. The OA trial group exhibited reduced cell proliferation at 48, 72, and 96 h after treatment. The OA model, OA trial, and NC groups all contained more cells arrested in G1 phase and had higher apoptosis rates than the blank group. Additionally, the OA trial group contained more cells arrested in G1 phase, with increased apoptosis rates compared to the OA model and NC groups. The OA model group had lowest expression of cyclin D1 whereas the blank group contained the highest among the four groups. qRT-PCR also showed that the OA model, OA trial, and NC groups all had increased expression levels of Bax and reduced expression levels of Bcl-2 and P53 compared to the blank group, whereby by the OA group had the most significant change. The combined evidence in our study shows that cyclin D1 gene silencing suppresses proliferation and induces apoptosis of rat chondrocytes in IL-1β-induced OA. J. Cell. Biochem. 119: 290-299, 2018. © 2017 Wiley Periodicals, Inc.

Roles of cancer/testis antigens (CTAs) in breast cancer

Breast cancer is the most common cancer diagnosed and is the second leading cause of cancer death among women in the US. For breast cancer, early diagnosis and efficient therapy remains a significant clinical challenge. Therefore, it is necessary to identify novel tumor associated molecules to target for biomarker development and immunotherapy. In this regard, cancer testis antigens (CTAs) have emerged as a potential clinical biomarker targeting immunotherapy for various malignancies due to the nature of its characteristics. CTAs are a group of tumor associated antigens (TAAs) that display normal expression in immune-privileged organs, but display aberrant expression in several types of cancers, particularly in advanced cancers. Investigation of CTAs for the clinical management of breast malignancies indicates that these TAAs have potential roles as novel biomarkers, with increased specificity and sensitivity compared to those currently used in the clinic. Moreover, TAAs could be therapeutic targets for cancer immunotherapy. This review is an attempt to address the promising CTAs in breast cancer and their possible clinical implications as biomarkers and immunotherapeutic targets with particular focus on challenges and future interventions.

Prognostic stratification improvement by integrating ID1/ID3/IGJ gene expression signature and immunophenotypic profile in adult patients with B-ALL

Background

Survival of adults with B-Acute Lymphoblastic Leukemia requires accurate risk stratification of patients in order to provide the appropriate therapy. Contemporary techniques, using clinical and cytogenetic variables are incomplete for prognosis prediction.

Methods

To improve the classification of adult patients diagnosed with B-ALL into prognosis groups, two strategies were examined and combined: the expression of the ID1/ID3/IGJ gene signature by RT-PCR and the immunophenotypic profile of 19 markers proposed in the EuroFlow protocol by Flow Cytometry in bone marrow samples.

Results

Both techniques were correlated to stratify patients into prognostic groups. An inverse relationship between survival and expression of the three-genes signature was observed and an immunophenotypic profile associated with clinical outcome was identified. Markers CD10 and CD20 were correlated with simultaneous overexpression of ID1, ID3 and IGJ. Patients with simultaneous expression of the poor prognosis gene signature and overexpression of CD10 or CD20, had worse Event Free Survival and Overall Survival than patients who had either the poor prognosis gene expression signature or only CD20 or CD10 overexpressed.

Conclusion

By utilizing the combined evaluation of these two immunophenotypic markers along with the poor prognosis gene expression signature, the risk stratification can be significantly strengthened. Further studies including a large number of patients are needed to confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0506-4) contains supplementary material, which is available to authorized users.

Prognostic value of tissue-based biomarker signature in clear cell renal cell carcinoma

OBJECTIVE

To improve risk stratification for recurrence prognostication in patients with localised clear cell renal cell carcinoma (ccRCC).

PATIENTS AND METHODS

In all, 367 patients with non-metastatic ccRCC were included. The cohort was divided into a training and validation set. Using tissue microarrays, immunostaining was performed for 24 biomarkers representative of key pathways in ccRCC. Using Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression, we identified several markers that were used to construct a risk classifier for risk of disease recurrence.

RESULTS

The median (interquartile range) follow-up was 63.5 (24.0-85.3) months. Five out of 24 markers were selected by LASSO Cox regression for the risk classifier: N-cadherin, E-cadherin, Ki67, cyclin D1 and phosphorylated eukaryotic initiation factor 4E binding protein-1 (p-4EBP1). Patients were classified as either low, intermediate or high risk of disease recurrence by tertiles of risk score. The 5-year recurrence-free survival (RFS) was 93.8%, 87.7% and 70% for patients with low-, intermediate- and high-risk scores, respectively (P < 0.001). Patients with a high marker score had worse RFS on multivariate analysis adjusted for age, gender, race and the Mayo Clinic Stage, Size, Grade, and Necrosis (SSIGN) score (hazard ratio 3.66, 95% confidence interval 1.58-8.49, P = 0.003 for high vs low marker score in the overall cohort). The five-marker classifier increased the concordance index of the clinical model in both the training and validation sets.

CONCLUSION

We developed a five-marker-based prognostic tool that can effectively classify patients with ccRCC according to risk of disease recurrence after surgery. This tool, if prospectively validated, could provide individualised risk estimation for patients with ccRCC.

Association of CCND1 Gene c.870G>A Polymorphism with Breast Cancer Risk: A Case-ControlStudy and a Meta-Analysis

Cyclin D1 (CCND1) plays an essential role in regulating the progress of the cell cycle from G1 to S phase. There is a common c.870G>A polymorphism in the CCND1 gene. The aim of this study was to investigate the association of CCND1 gene c.870G>A polymorphism with breast cancer risk in a case-control study, which followed by a meta-analysis and an in silico analysis. Three hundred and thirty-five subjects composed of 174 women with breast cancer and 161 healthy controls were included in the case-control study. CCND1 gene c.870G>A genotyping was performed by PCR-RFLP. Meta-analysis was done for 14 studies composed of 7281 cases and 6820 controls. Some bioinformatics tools were applied to investigate the effects of c.870G>A on the mRNA splicing and structure. Our data obtained from case-control study revealed that GA genotype (OR: 1.89, 95%CI: 1.12-3.17, p = 0.017), AA genotype (OR: 1.95, 95%CI: 1.08-3.53, p = 0.027), and A allele (OR: 1.44, 95%CI: 1.06-1.95, p = 0.019) were significantly associated with breast cancer risk. The results of meta-analysis showed a significant association between CCND1 c.870G>A polymorphism and breast cancer risk, especially in Caucasian population. In silico analysis revealed that c.870G>A transition affect CCND1 mRNA splicing and secondary structure.

Cyclin-dependent kinase-mediated phosphorylation of breast cancer metastasis suppressor 1 (BRMS1) affects cell migration

Expression of Breast Cancer Metastasis Suppressor 1 (BRMS1) reduces the incidence of metastasis in many human cancers, without affecting tumorigenesis. BRMS1 carries out this function through several mechanisms, including regulation of gene expression by binding to the mSin3/histone deacetylase (HDAC) transcriptional repressor complex. In the present study, we show that BRMS1 is a novel substrate of Cyclin-Dependent Kinase 2 (CDK2) that is phosphorylated on serine 237 (S237). Although CDKs are known to regulate cell cycle progression, the mutation of BRMS1 on serine 237 did not affect cell cycle progression and proliferation of MDA-MB-231 breast cancer cells; however, their migration was affected. Phosphorylation of BRMS1 does not affect its association with the mSin3/HDAC transcriptional repressor complex or its transcriptional repressor activity. The serine 237 phosphorylation site is immediately proximal to a C-terminal nuclear localization sequence that plays an important role in BRMS1-mediated metastasis suppression but phosphorylation does not control BRMS1 subcellular localization. Our studies demonstrate that CDK-mediated phosphorylation of BRMS1 regulates the migration of tumor cells.

Hypoglycemia Enhances Epithelial-Mesenchymal Transition and Invasiveness, and Restrains the Warburg Phenotype, in Hypoxic HeLa Cell Cultures and Microspheroids

The accelerated growth of solid tumors leads to episodes of both hypoxia and hypoglycemia (HH) affecting their intermediary metabolism, signal transduction, and transcriptional activity. A previous study showed that normoxia (20% O₂ ) plus 24 h hypoglycemia (2.5 mM glucose) increased glycolytic flux whereas oxidative phosphorylation (OxPhos) was unchanged versus normoglycemia in HeLa cells. However, the simultaneous effect of HH on energy metabolism has not been yet examined. Therefore, the effect of hypoxia (0.1-1% O₂ ) plus hypoglycemia on the energy metabolism of HeLa cells was analyzed by evaluating protein content and activity, along with fluxes of both glycolysis and OxPhos. Under hypoxia, in which cell growth ceased and OxPhos enzyme activities, ΔΨm and flux were depressed, hypoglycemia did not stimulate glycolytic flux despite increasing H-RAS, p-AMPK, GLUT1, GLUT3, and HKI levels, and further decreasing mitochondrial enzyme content. The impaired mitochondrial function in HH cells correlated with mitophagy activation. The depressed OxPhos and unchanged glycolysis pattern was also observed in quiescent cells from mature multicellular tumor spheroids, suggesting that these inner cell layers are similarly subjected to HH. The principal ATP supplier was glycolysis for HH 2D monolayer and 3D quiescent spheroid cells. Accordingly, the glycolytic inhibitors iodoacetate and gossypol were more effective than mitochondrial inhibitors in decreasing HH-cancer cell viability. Under HH, stem cell-, angiogenic-, and EMT-biomarkers, as well as glycoprotein-P content and invasiveness, were also enhanced. These observations indicate that HH cancer cells develop an attenuated Warburg and pronounced EMT- and invasive-phenotype. J. Cell. Physiol. 232: 1346-1359, 2017. © 2016 Wiley Periodicals, Inc.

Mesenchymal Stromal Cells Epithelial Transition Induced by Renal Tubular Cells-Derived Extracellular Vesicles

Mesenchymal-epithelial interactions play an important role in renal tubular morphogenesis and in maintaining the structure of the kidney. The aim of this study was to investigate whether extracellular vesicles (EVs) produced by human renal proximal tubular epithelial cells (RPTECs) may induce mesenchymal-epithelial transition of bone marrow-derived mesenchymal stromal cells (MSCs). To test this hypothesis, we characterized the phenotype and the RNA content of EVs and we evaluated the in vitro uptake and activity of EVs on MSCs. MicroRNA (miRNA) analysis suggested the possible implication of the miR-200 family carried by EVs in the epithelial commitment of MSCs. Bone marrow-derived MSCs were incubated with EVs, or RPTEC-derived total conditioned medium, or conditioned medium depleted of EVs. As a positive control, MSCs were co-cultured in a transwell system with RPTECs. Epithelial commitment of MSCs was assessed by real time PCR and by immunofluorescence analysis of cellular expression of specific mesenchymal and epithelial markers. After one week of incubation with EVs and total conditioned medium, we observed mesenchymal-epithelial transition in MSCs. Stimulation with conditioned medium depleted of EVs did not induce any change in mesenchymal and epithelial gene expression. Since EVs were found to contain the miR-200 family, we transfected MSCs using synthetic miR-200 mimics. After one week of transfection, mesenchymal-epithelial transition was induced in MSCs. In conclusion, miR-200 carrying EVs released from RPTECs induce the epithelial commitment of MSCs that may contribute to their regenerative potential. Based on experiments of MSC transfection with miR-200 mimics, we suggested that the miR-200 family may be involved in mesenchymal-epithelial transition of MSCs.

Overexpression of Id1 in transgenic mice promotes mammary basal stem cell activity and breast tumorigenesis

Inhibitor of differentiation/DNA binding (Id)1 is a crucial regulator of mammary development and breast cancer progression. However, its effect on stemness and tumorigenesis in mammary epithelial cells remains undefined. Herein, we demonstrate that Id1 induces mammary tumorigenesis by increasing normal and malignant mammary stem cell (MaSC) activities in transgenic mice. MaSC-enriched basal cell expansion and increased self-renewal and in vivo regenerative capacity of MaSCs are observed in the mammary glands of MMTV-Id1 transgenic mice. Furthermore, MMTV-Id1 mice develop ductal hyperplasia and mammary tumors with highly expressed basal markers. Id1 also increases breast cancer stem cell (CSC) population and activity in human breast cancer lines. Moreover, the effects of Id1 on normal and malignant stem cell activities are mediated by the Wnt/c-Myc pathway. Collectively, these findings provide in vivo genetic evidence of Id1 functions as an oncogene in breast cancer and indicate that Id1 regulates mammary basal stem cells by activating the Wnt/c-Myc pathway, thereby contributing to breast tumor development.

F344/NTac Rats Chronically Exposed to Bromodichloroacetic Acid Develop Mammary Adenocarcinomas With Mixed Luminal/Basal Phenotype and Tgfβ Dysregulation

Breast cancer is the most common cancer and the second-leading cause of cancer mortality in women in the United States. A recent 2-year National Toxicology Program carcinogenicity study showed an increased incidence of proliferative mammary lesions (hyperplasia, fibroadenoma, adenocarcinoma) in F344/NTac rats exposed to bromodichloroacetic acid (BDCA), a disinfection by-product in finished drinking water with widespread human exposure. We hypothesized that the increase in mammary tumors observed in BDCA-exposed F344/NTac rats may be due to underlying molecular changes relevant for human breast cancer. The objective of the study was to compare (1) gene and protein expression and (2) mutation spectra of relevant human breast cancer genes between normal untreated mammary gland and mammary tumors from control and BDCA-exposed animals to identify molecular changes relevant for human cancer. Histologically, adenocarcinomas from control and BDCA-exposed animals were morphologically very similar, were estrogen/progesterone receptor positive, and displayed a mixed luminal/basal phenotype. Gene expression analysis showed a positive trend in the number of genes associated with human breast cancer, with proportionally more genes represented in the BDCA-treated tumor group. Additionally, a 5-gene signature representing possible Tgfβ pathway activation in BDCA-treated adenocarcinomas was observed, suggesting that this pathway may be involved in the increased incidence of mammary tumors in BDCA-exposed animals.

MiR-195 inhibits the proliferation of human cervical cancer cells by directly targeting cyclin D1

MicroRNAs are important regulators of multiple cellular processes, and aberrant miRNA expression has been observed in human cervical cancer (CC). The present study was to evaluate the level of miR-195 and cyclin D1 in CC tissues and cells. We further investigated the molecular mechanisms of miR-195 and cyclin D1 in CC cell lines HeLa and SiHa. Here, we found that miR-195 expression was down-regulated in CC tissues, and HeLa and SiHa cells (all p < 0.001). By contrast, cyclin D1 was up-regulated. Furthermore, the expression of miR-195 was inversely proportional to that of cyclin D1 mRNA or protein (p = 0.013, p = 0.015, respectively). In vitro studies demonstrated that the overexpression of miR-195 played a suppressor role in the proliferation of HeLa and SiHa cells and promoted cell apoptosis. Luciferase reporter assays confirmed that miR-195 binding to the 3'-UTR regions of cyclin D1 inhibited the expression of cyclin D1 in HeLa and SiHa cells. However, the inhibitor of miR-195 promoted the expression of cyclin D1 and cell proliferation. In conclusion, our data suggest that miR-195 may have the potential role in treatment of CC patients, as well as miR-195 is a novel regulator of invasiveness and tumorigenicity in CC cells by targeting cyclin D1. MiR-195/cyclin D1 pathway may be a useful therapeutic agent in CC patients.