Epithelial-to-mesenchymal transition in gallbladder cancer: from clinical evidence to cellular regulatory networks

Functional relevance of MMP2 promoter variants in gallbladder cancer: A case-control study in an Eastern Indian Population

Gallbladder cancer (GBC) is a prevalent and deadly form of bile duct cancer, associated with poor prognosis. This study aimed to investigate the genetic factors contributing to the high incidence of GBC in certain geographical regions, particularly in the Northern and Eastern parts of India. The present case-control study focused on MMP2, a gene involved in tumor progression and metastasis, as a potential candidate in GBC pathogenesis. We scanned MMP2 promoter for twelve SNPs using Sanger's sequencing and carried out a case-control study in 300 cases and 300 control samples. We found five rare variants (rs1961998763, rs1961996235, rs1391392808, rs1488656253, and rs17859816) and one nonpolymorphic SNP (rs17859817). Our results revealed a significant association between GBC and MMP2 promoter SNPs, rs243865 (Allelic-Padjusted = 0.0353) and g.55477735G > A (Allelic-Padjusted = 9.22E-05). Moreover, the haplotype "C-C-A-C-C" exhibited a significant association with GBC (P = 4.23E-05). Genotype-phenotype correlation for variant rs243865, in the GBC patient tissue samples, established that 'T' risk allele carriers had higher expression levels of MMP2. Additionally, luciferase reporter assay in HEK293T cells revealed the probable regulatory role of rs243865 variant allele 'T' in MMP2 expression. Our study uncovers the association of MMP2 promoter SNPs with GBC and their role in regulating its expression.

Rho-Associated Protein Kinase Activity Is Required for Tissue Homeostasis in the Xenopus laevis Ciliated Epithelium

Lung epithelial development relies on the proper balance of cell proliferation and differentiation to maintain homeostasis. When this balance is disturbed, it can lead to diseases like cancer, where cells undergo hyperproliferation and then can undergo migration and metastasis. Lung cancer is one of the deadliest cancers, and even though there are a variety of therapeutic approaches, there are cases where treatment remains elusive. The rho-associated protein kinase (ROCK) has been thought to be an ideal molecular target due to its role in activating oncogenic signaling pathways. However, in a variety of cases, inhibition of ROCK has been shown to have the opposite outcome. Here, we show that ROCK inhibition with y-27632 causes abnormal epithelial tissue development in Xenopus laevis embryonic skin, which is an ideal model for studying lung cancer development. We found that treatment with y-27632 caused an increase in proliferation and the formation of ciliated epithelial outgrowths along the tail edge. Our results suggest that, in certain cases, ROCK inhibition can disturb tissue homeostasis. We anticipate that these findings could provide insight into possible mechanisms to overcome instances when ROCK inhibition results in heightened proliferation. Also, these findings are significant because y-27632 is a common pharmacological inhibitor used to study ROCK signaling, so it is important to know that in certain in vivo developmental models and conditions, this treatment can enhance proliferation rather than lead to cell cycle suppression.

Metastatic gallbladder cancer presenting as numb chin syndrome: A case report and literature review

Gallbladder cancer (GBC) is an uncommon malignancy that is highly aggressive in the advanced stages. However, it rarely metastasizes to the mandible. Numb chin syndrome (NCS) is a rare neurological manifestation associated with various underlying causes, including occult primary cancers and distant metastases. It is often considered to be a significant indicator of malignancy, and thorough investigation is essential in the presence of unclear etiology. The current study reported on the case of a 69-year-old Japanese woman who presented with numbness and mild pain in the lower lip and chin area for three months. No other systemic symptoms were observed. Immunocytochemical examination revealed the presence of an adenocarcinoma and TNM staging as per the Union for International Cancer Control and the American Joint Committee on Cancer guidelines confirmed stage IVb GBC. Comprehensive full-body positron emission tomography-computed tomography examination using 18F-fluoro-2-deoxy-D-glucose revealed additional bone and soft-tissue metastases. Palliative chemotherapy and radiation treatment were initiated based on the advanced stage of disease at the time of diagnosis. However, the patient succumbed to multiple organ failure six months later. The simultaneous occurrence of GBC, mandibular metastasis and NCS is rare and associated with poor prognosis. Despite the widespread nature of the disease, it can often manifest as non-specific oral symptoms without any systemic indications. The current study emphasizes the critical importance of timely confirmatory testing for accurate diagnosis and initiation of appropriate management for such complex conditions.

Decoding the role of long non-coding RNAs in gallbladder cancer pathogenesis: A review focus on signaling pathways interplay

Gallbladder cancer (GBC) is one of the most aggressive types of biliary tree cancers and the commonest despite its rarity. It is infrequently diagnosed at an early stage, further contributing to its poor prognosis and low survival rate. The lethal nature of the disease has underlined a crucial need to discern the underlying mechanisms of GBC carcinogenesis which are still largely unknown. However, with the continual evolution in the research of cancer biology and molecular genetics, studies have found that non-coding RNAs (ncRNAs) play an active role in the molecular pathophysiology of GBC development. Dysregulated long non-coding RNAs (lncRNAs) and their interaction with intracellular signaling pathways contribute to malignancy and disease development. LncRNAs, a subclass of ncRNAs with over 200 nucleotides, regulate gene expression at transcriptional, translational, and post-translational levels and especially as epigenetic modulators. Thus, their expression abnormalities have been linked to malignancy and therapeutic resistance. lnsRNAs have also been found in GBC patients' serum and tumor tissue biopsies, highlighting their potential as novel biomarkers and for targeted therapy. This review will examine the growing involvement of lncRNAs in GBC pathophysiology, including related signaling pathways and their wider clinical use.

FOXA2 suppresses gallbladder carcinoma cell migration, invasion, and epithelial-mesenchymal transition by targeting SERPINB5

BACKGROUND

Gallbladder cancer (GBC), a highly malignant gastrointestinal tumor, lacks effective therapies. Foxhead box A2 (FOXA2) is a tumor suppressor that is poorly expressed in various human malignancies. This study aimed to ascertain FOXA2 expression in GBC and its relevance to tumor metastasis, and to elucidate its regulatory mechanism with epithelial-mesenchymal transition (EMT) as an entry point, in the hope of providing a potential therapeutic target for GBC.

METHODS

FOXA2 expression in GBC tissues was first detected using immunohistochemistry (IHC), followed by correlation analysis with clinicopathological characteristics and survival prognosis. Subsequently, the effects of FOXA2 on GBC cell migration and invasion, as well as EMT induction, were evaluated by scratch, Transwell, RT-PCR, and Western blot assays, together with animal experimentation. Ultimately, mRNA sequencing was carried out to identify the key downstream target genes of FOXA2 in controlling the EMT process in GBC cells, and dual-luciferase reporter and chromatin immunoprecipitation assays were used to determine its regulatory mechanism.

RESULTS

FOXA2 was underexpressed in GBC tissues and inversely correlated with tumor node metastasis stage, lymph node metastasis, and poor patient prognosis. FOXA2 exerts suppressive effects on EMT and metastasis of GBC in vivo and in vitro. FOXA2 can impede GBC cell migratory and invasive functions and EMT by positively mediating serine protein kinase inhibitor B5 (SERPINB5) expression.

CONCLUSION

FOXA2 directly binds to the SERPINB5 promoter region to stimulate its transcription, thereby modulating the migration and invasion behaviors of GBC cells as well as the EMT process, which might be an effective therapeutic target against GBC.

Phase 2 trial of bintrafusp alfa as second-line therapy for patients with locally advanced/metastatic biliary tract cancers

BACKGROUND AND AIMS

Biliary tract cancers are rare, heterogeneous cancers with poor prognoses. Bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of TGF-βRII (a TGF-β "trap") fused to a human IgG1 monoclonal antibody blocking programmed death ligand 1, was evaluated in patients with locally advanced/metastatic chemorefractory biliary tract cancers.

APPROACH AND RESULTS

This multicenter, single-arm, open-label, phase 2 study (NCT03833661) enrolled adults with locally advanced or metastatic biliary tract cancer that was intolerant to or had failed first-line systemic platinum-based chemotherapy. Patients received 1200 mg bintrafusp alfa intravenously Q2W. The primary endpoint was confirmed objective response according to Response Evaluation Criteria in Solid Tumors 1.1 assessed by IRC. Secondary endpoints included duration of response, durable response rate, safety, progression-free survival, and overall survival.Between March 2019 and January 2020, 159 patients were enrolled. Median follow-up was 16.1 (range, 0.0-19.3) months; 17 patients (10.7%; 95% CI: 6.4%-16.6%) achieved an objective response. Median duration of response was 10.0 (range, 1.9-15.7) months; 10 patients (6.3%; 95% CI: 3.1%-11.3%) had a durable response (≥6 mo). Median progression-free survival was 1.8 months (95% CI: 1.7-1.8 mo); median overall survival was 7.6 months (95% CI: 5.8-9.7 mo). Overall survival rates were 57.9% (6 mo) and 38.8% (12 mo). Grade ≥3 adverse events occurred in 26.4% of patients, including one treatment-related death (hepatic failure). Frequent grade ≥3 adverse events included anemia (3.8%), pruritus (1.9%), and increased alanine aminotransferase (1.9%).

CONCLUSIONS

Although this study did not meet its prespecified primary endpoint, bintrafusp alfa demonstrated clinical activity as second-line treatment in this hard-to-treat cancer, with durable responses and a manageable safety profile.

Extracellular Vesicles Released from Cancer Cells Promote Tumorigenesis by Inducing Epithelial to Mesenchymal Transition via β-Catenin Signaling

Lung cancer is the leading cause of cancer-related deaths globally, in part due to a lack of early diagnostic tools and effective pharmacological interventions. Extracellular vesicles (EVs) are lipid-based membrane-bound particles released from all living cells in both physiological and pathological states. To understand the effects of lung-cancer-derived EVs on healthy cells, we isolated and characterized EVs derived from A549 lung adenocarcinoma cells and transferred them to healthy human bronchial epithelial cells (16HBe14o). We found that A549-derived EVs carry oncogenic proteins involved in the pathway of epithelial to mesenchymal transition (EMT) that are regulated by β-catenin. The exposure of 16HBe14o cells to A549-derived EVs resulted in a significant increase in cell proliferation, migration, and invasion via upregulating EMT markers such as E-Cadherin, Snail, and Vimentin and cell adhesion molecules such as CEACAM-5, ICAM-1, and VCAM-1, with concomitant downregulation of EpCAM. Our study suggests a role for cancer-cell-derived EVs to induce tumorigenesis in adjacent healthy cells by promoting EMT via β-catenin signaling.

NCK-associated protein 1 regulates metastasis and is a novel prognostic marker for colorectal cancer

Metastatic colorectal cancer (CRC) remains a substantial problem for mortality and requires screening and early detection efforts to increase survival. Epithelial-mesenchymal transition (EMT) and circulation of tumor cells in the blood play important roles in metastasis. To identify a novel target for metastasis of CRC, we conducted a gene microarray analysis using extracted RNA from the blood of preclinical models. We found that NCK-associated protein 1 (NCKAP1) was significantly increased in the blood RNA of patient-derived xenograft (PDX) models of colon cancer. In the NCKAP1 gene knockdown-induced human colon cancer cell lines HCT116 and HT29, there was a reduced wound healing area and significant inhibition of migration and invasion. As the result of marker screening for cytoskeleton and cellular interactions, CRC treated with siRNA of NCKAP1 exhibited significant induction of CDH1 and phalloidin expression, which indicates enhanced adherent cell junctions and cytoskeleton. In HCT116 cells with a mesenchymal state induced by TGFβ1, metastasis was inhibited by NCKAP1 gene knockdown through the inhibition of migration, and there was increased CTNNB1 expression and decreased FN expression. We established metastasis models for colon cancer to liver transition by intrasplenic injection shRNA of NCKAP1-transfected HCT116 cells or by implanting tumor tissue generated with the cells on cecal pouch. In metastasis xenograft models, tumor growth and liver metastasis were markedly reduced. Taken together, these data demonstrate that NCKAP1 is a novel gene regulating EMT that can contribute to developing a diagnostic marker for the progression of metastasis and new therapeutics for metastatic CRC treatment.

HHLA2 promotes tumor progression by long non‑coding RNA H19 in human gallbladder cancer

Advanced gallbladder cancer (GBC) is one of the most malignant of all types of biliary tract cancers that is associated with poor prognosis and high mortality. Accumulating evidence suggest that the B7 family of proteins serve an essential role in various types of cancers, including GBC. However, the potential function and regulatory mechanism of human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2; also known as B7-H7 or B7H5) in GBC remain poorly understood. In the present study, immunohistochemistry was used to examine the expression pattern of HHLA2 in samples from 89 patients with GBC. The possible association between HHLA2 expression and the clinicopathological parameters, including prognosis, were then assessed. Using lentiviruses, overexpression of HHLA2 plasmid or short-hairpin RNA (shRNA) of HHLA2 were transfected into GBC-SD cells to overexpress or knock down HHLA2 expression, respectively. The effects of HHLA2 overexpression and knockdown on the epithelial-mesenchymal transition (EMT) process on GBC-SD cells were measured by the western blotting and immunofluorescence staining of collagen I, N-cadherin, E-cadherin, vimentin and α-SMA. By contrast, changes in cell proliferation were measured using EdU assay. Cell invasion and migration were assessed using Transwell and wound-healing assays, respectively. In addition, a xenograft mouse model was established to evaluate the tumorigenic ability of the GBC cell line in vivo after stable transfection with lentivirus for HHLA2 overexpression or shRNA for HHLA2 knockdown. The regulatory relationships among TGF-β1, long non-coding RNA (lncRNA) H19 (H19) and HHLA2 were then investigated. The mRNA expression of lncRNA H19 were assessed using reverse transcription-quantitative PCR, whereas the expression levels of HHLA2 were detected by western blotting and immunofluorescence staining. HHLA2 expression was found to gradually increase as the stages of the GBC samples become more advanced. In addition, the expression level of HHLA2 was calculated to be positively associated with the Nevin stage, American Joint Committee on Cancer stage, tumor invasion and regional lymph node metastasis but was negatively associated with the overall patient survival (OS). In vitro experiments demonstrated that overexpression of HHLA2 promoted GBC migration, invasion, proliferation and EMT, whereas in vivo experiments found a promoting role of HHLA2 overexpression on GBC tumor growth. After transfection with lentiviruses encoding the overexpression plasmid of lncRNA H19, GBC migration, invasion, proliferation and EMT were increased. By contrast, knocking down HHLA2 expression suppressed TGF-β1- or lncRNA H19 overexpression-induced GBC migration, invasion, proliferation and EMT. In addition, HHLA2 knockdown significantly reduced the sizes of the GBC tumors in vivo. These results suggest that HHLA2 overexpression can promote GBC progression. Conversely, ablation of HHLA2 expression inhibited both TGF-β1- and lncRNA H19-induced GBC progression, suggesting that HHLA2 is a potential therapeutic target for this disease.

The crossroads of adenosinergic pathway and epithelial-mesenchymal plasticity in cancer

Epithelial-mesenchymal transition (EMT) is a key mechanism related to tumor progression, invasion, metastasis, resistance to therapy and poor prognosis in several types of cancer. However, targeting EMT or partial-EMT, as well as the molecules involved in this process, has remained a challenge. Recently, the CD73 enzyme, which hydrolyzes AMP to produce adenosine (ADO), has been linked to the EMT process. This relationship is not only due to the production of the immunosuppressant ADO but also to its role as a receptor for extracellular matrix proteins, being involved in cell adhesion and migration. This article reviews the crosstalk between the adenosinergic pathway and the EMT program and the impact of this interrelation on cancer development and progression. An in silico analysis of RNAseq datasets showed that several tumor types have a significant correlation between an EMT score and NT5E (CD73) and ENTPD1 (CD39) expressions, with the strongest correlations in prostate adenocarcinoma. Furthermore, it is evident that the cooperation between EMT and adenosinergic pathway in tumor progression is context and tumor-dependent. The increased knowledge about this topic will help broaden the view to explore new treatments and therapies for different types of cancer.

Cinnamaldehyde decreases the invasion and u-PA expression of osteosarcoma by down-regulating the FAK signalling pathway

Cancer metastasis is the major cause of the high mortality risk of patients with osteosarcoma. Cinnamaldehyde has been shown to exhibit multiple tumour-suppressing activities, but its role in human osteosarcoma is not yet completely defined. In this study, the antimetastatic effect of cinnamaldehyde on highly metastatic human osteosarcoma cells was observed in vitro and in vivo using Saos-2 and 143B cells. Cinnamaldehyde reduced the activity and protein level of urokinase-type plasminogen activator (u-PA) and suppressed the invasion ability of osteosarcoma cells by inhibiting the phosphorylation of focal adhesion kinase. In addition, cinnamaldehyde reduced cell movement, cell-matrix adhesion, and the expression of the mesenchymal markers of epithelial-to-mesenchymal transition, namely, fibronectin and N-cadherin. Importantly, the oral administration of cinnamaldehyde remarkably suppressed the pulmonary metastasis of osteosarcoma in mice. Results indicated that cinnamaldehyde has therapeutic potential for inhibiting osteosarcoma metastasis.

MicroRNA-30c-2-3p represses malignant progression of gastric adenocarcinoma cells via targeting ARHGAP11A

MicroRNAs are crucial tumor regulators to tumor development and progression. MiR-30c-2-3p can suppress malignant progression of tumor cells, but no study has reported the modulatory process of miR-30c-2-3p in gastric adenocarcinoma (GA). We herein investigated role of miR-30c-2-3p in GA cells. Here, we evaluated gene level in cancer cells by qRT-PCR. CCK-8, colony formation, flow cytometry, and transwell assays revealed biological functions of miR-30c-2-3p and ARHGAP11A. Genes downstream of miR-30c-2-3p were acquired through bioinformatics analysis. Our results suggested a low level of miR-30c-2-3p in GA tissue and cells, while its high expression could repress the malignant progression and promote cell cycle arrest and apoptosis of GA cells. Besides, ARHGAP11A was downstream of miR-30c-2-3p, with up-regulated ARHGAP11A facilitating malignant progression and repressing cell cycle arrest and apoptosis of GA cells. In addition, changes in GA cell functions caused by high ARHGAP11A expression could be partially offset by enhancing miR-30c-2-3p. Thus, our observations indicated that miR-30c-2-3p was a tumor repressor that could inhibit GA progression via modulating ARHGAP11A.

CD73 and PD-L1 as Potential Therapeutic Targets in Gallbladder Cancer

Gallbladder cancer (GBC) is one of the most common and aggressive biliary tract cancers with a dismal prognosis. Ongoing clinical trials are evaluating a few selected immune checkpoint inhibitors (ICIs) as monotherapy for the treatment of GBC patients. However, only a subset of patients benefits from these treatments. To improve ICI therapy response, molecular mechanisms that confer resistance to immune checkpoint (IC) blockade needs to be explored. Epithelial-to-mesenchymal transition (EMT) program and cancer stem cells (CSCs) have been implicated as key processes that confer ICI treatment resistance. However, in GBC the EMT-CSC-IC axis has not yet been clearly elucidated. This study aims to examine the aberrant expression of ICs associated with CSC and EMT. We successfully enriched CSCs by utilizing a 3-dimensional culture system and established a reversible EMT model with human GBC NOZ cell line. Notably, ICs CD73 and PD-L1 were closely associated with both CSC and EMT phenotypes. Knockdown of CD73 or PD-L1 reduced the proliferative and motile abilities of both adherent monolayers and anchorage-free spheroids. In conclusion, blocking CD73 and PD-L1 offer a promising therapeutic strategy for targeting highly aggressive populations with CSC and EMT phenotype to improve GBC patient prognosis.

KIF15 knockdown suppresses gallbladder cancer development

Gallbladder cancer (GBC) is commonly regarded as one of the most lethal malignant tumor types with poor prognosis. Kinesin family member 15 (KIF15) is reported to be tightly related with progression of multiple cancer types which, however, has not been clarified in GBC so far. KIF15 was significantly up-regulated in clinical GBC tissues compared with that in para-carcinoma tissues and the expression level was also correlated with tumor malignancies. In addition to tissues, GBC cells also exhibited a high expression abundance of KIF15. After down-regulating KIF15 via lentiviral transfection, GBC cell proliferation and migration were both inhibited, while cell apoptosis was promoted markedly. Likewise, silencing KIF15 significantly interfered the growth of nude mouse xenografts. Our experiments in GBC cell lines also demonstrated that KIF15 overexpression accelerated cell proliferation but lessened cell apoptosis in both GBC-SD and SGC-996 cells. Further investigation of the mechanism occurring in GBC inhibition mediated by KIF15 knockdown revealed that KIF15 deficiency led to decreased activity of several signaling pathways (TNF, PI3K/AKT and MAPK), a reduction of CDK6 expression regulated by enhanced p21, and HSP60 absence. Following the treatment of shCtrl- and shKIF15-transfected cells with AKT activator, we found that anti-tumor effects resulting from KIF15 deficiency could be relieved by AKT activator in both experimental cells. Overall, for the first time, we demonstrated that KIF15 was overexpressed in GBC and displayed a close relationship between KIF15 levels and GBC clinical stages. Furthermore, low expression of KIF15 resulted in obvious anti-tumor effects.

Unraveling the roles of miRNAs in regulating epithelial-to-mesenchymal transition (EMT) in osteosarcoma

Osteosarcoma is one of the most prevalent primary bone tumors with a high metastatic and recurrence rate with poor prognosis. MiRNAs are short and non-coding RNAs that could regulate various cellular activities and one of them is the epithelial-to-mesenchymal transition (EMT). Osteosarcoma cells that have undergone EMT would lose their cellular polarity and acquire invasive and metastatic characteristics. Our literature search showed that many pre-clinical and clinical studies have reported the roles of miRNAs in modulating the EMT process in osteosarcoma and compared to other cancers like breast cancer, there is a lack of review article which effectively summarizes the various roles of EMT-regulating miRNAs in osteosarcoma. This review, therefore, was aimed to discuss and summarize the EMT-promoting and EMT-suppressing roles of different miRNAs in osteosarcoma. The review would begin with the discussion on the concepts and principles of EMT, followed by the exploration of the diverse roles of EMT-regulating miRNAs in osteosarcoma. Subsequently, the potential use of miRNAs as prognostic biomarkers in osteosarcoma to predict the likelihood of metastases and as therapeutic agents would be discussed.

Melatonin inhibits gallbladder cancer cell migration and invasion via ERK-mediated induction of epithelial-to-mesenchymal transition

Melatonin is a naturally occurring molecule secreted by the pineal gland that exhibits antitumor properties and prevents the development of human cancer. However, little is known regarding the effects of melatonin on gallbladder cancer (GBC) cells. The present study aimed to investigate the role of melatonin on the prevention of GBC cell invasion. The GBC cell line, GBC-SD, was treated with different concentrations of melatonin for different time periods, and the data indicated that melatonin markedly inhibited the invasion of GBC cells. Following treatment of GBC cells with melatonin, the protein levels of the epithelial marker, E-cadherin, significantly increased, while the expression levels of the mesenchymal markers, N-cadherin, Snail and vimentin, notably decreased. In addition, melatonin inhibited the phosphorylation of ERK1/2. Following treatment of the cells with the ERK activator, tert-Butylhydroquinone, the anti-invasive effects of melatonin were reversed by rescuing epithelial-to-mesenchymal transition in GBC cells. Taken together, these results suggest that melatonin inhibits GBC invasiveness by blocking the ERK signaling pathway. Thus, melatonin may be used as a potential novel cancer therapeutic drug for the treatment of GBC.

Interleukin 17A promotes gallbladder cancer invasiveness via ERK/NF-κB signal pathway mediated epithelial-to-mesenchymal transition

As a pro-inflammatory cytokine, Interleukin 17A (IL-17A) plays an important role in pathology of tumor microenvironment and inflammatory diseases. In this study, we intend to investigate the role of IL-17A on the metastasis of gallbladder cancer (GBC) and related mechanisms. The serum levels of IL-17A were associated with node metastasis and advanced stage. We also found the pro-invasion effect of IL-17A on GBC cells. When treated with IL-17A, the protein level of epithelial marker E-cadherin in GBC cells was significantly down-regulated, while the protein level of the mesenchymal phenotype marker vimentin was significantly increased. IL-17A increased the expression of transcription factor slug, the phosphorylation of ERK1/2 and the nuclear translocation of NF-κB/p50 and p65 in a concentration-dependent manner. Pretreatment of cells with U0126 could reverse the nuclear translocation of NF-κB/p50 and p65 and EMT induced by IL-17A. IL-17A promotes gallbladder cancer invasiveness via ERK/NF-κB signal pathway mediated epithelial-to-mesenchymal transition. As a new therapeutic targets and diagnostic marker, IL-17A may play an important role in the treatment of GBC.

Genomic Profiling of Biliary Tract Cancer Cell Lines Reveals Molecular Subtypes and Actionable Drug Targets

Biliary tract cancers (BTCs) currently have no approved targeted therapies. Although genomic profiling of primary BTCs has identified multiple potential drug targets, accurate models are needed for their evaluation. Genomic profiling of 22 BTC cell lines revealed they harbor similar mutational signatures, recurrently mutated genes, and genomic alterations to primary tumors. Transcriptomic profiling identified two major subtypes, enriched for epithelial and mesenchymal genes, which were also evident in patient-derived organoids and primary tumors. Interrogating these models revealed multiple mechanisms of MAPK signaling activation in BTC, including co-occurrence of low-activity BRAF and MEK mutations with receptor tyrosine kinase overexpression. Finally, BTC cell lines with altered ERBB2 or FGFRs were exquisitely sensitive to specific targeted agents, whereas surprisingly, IDH1-mutant lines did not respond to IDH1 inhibitors in vitro. These findings establish BTC cell lines as robust models of primary disease, reveal specific molecular disease subsets, and highlight specific molecular vulnerabilities in these cancers.

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BTC cell lines harbor similar genomic alterations to primary tumors

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Transcriptomic profiling of BTC cell lines identified two molecular subtypes

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MAPK signaling is activated in BTC via multiple mechanisms

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BTC lines with deregulated ERBB2 or FGFRs respond to specific targeted therapies

Molecular pathways and potential biomarkers in gallbladder cancer: A comprehensive review

The most common malignancy of the biliary tract, gallbladder cancer (GBC) often has a dismal prognosis. The aggressive nature of the tumor, delayed diagnosis at advanced stages of the disease, and lack of effective treatment options are some of the factors that contribute to a poor outcome. Early detection and accurate assessment of disease burden is critical to optimize management and improve long-term survival, as well as identify patients for adjuvant therapy and clinical trials. With recent advances in the understanding of the molecular pathogenesis of GBC, several specific diagnostic and biomarkers have been proposed as being of diagnostic and prognostic importance. Indeed, identification of novel diagnostic and prognostic markers has an important role in early diagnosis and development of targeted therapies among patients with GBC. Next-generation sequencing technology and genomewide data analysis have provided novel insight into understanding the molecular pathogenesis of biliary tract cancers, thereby identifying potential biomarkers for clinical use. We herein review available GBC biomarkers and the potential clinical implications in the management of GBC.

MBD1 promotes the malignant behavior of gallbladder cancer cells and induces chemotherapeutic resistance to gemcitabine

Background

Methyl-CpG binding domain protein 1 (MBD1), which couples DNA methylation to transcriptional repression, has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell cycle progression and development. It has also been proven that MBD1 is involved in tumor development and progression. However, whether MBD1 is involved in tumorigenesis, especially in gallbladder cancer, is totally unknown.

Methods

Human GBC-SD and SGC996 cells were used to perform experiments. Invasion, wound healing and colony formation assays were performed to evaluate cell viability. A CCK-8 assay was performed to assess gallbladder cancer cell viability after gemcitabine treatment. Western blot analysis was used to evaluate changes in protein expression. Human gallbladder cancer tissues and adjacent nontumor tissues were subjected to immunohistochemical staining to detect protein expression.

Results

We found that MBD1 expression was significantly upregulated in gallbladder cancer tissues compared with that in surrounding normal tissues according to immunohistochemical analysis of 84 surgically resected gallbladder cancer specimens. These data also indicated that higher MBD1 expression was correlated with lymph node metastasis and poor survival in gallbladder cancer patients. Overexpression and deletion in vitro validated MBD1 as a potent oncogene promoting malignant behaviors in gallbladder cancer cells, including invasion, proliferation and migration, as well as epithelial–mesenchymal transition. Studies have demonstrated that epithelial–mesenchymal transition is common in gallbladder cancer, and it is well known that drug resistance and epithelial–mesenchymal transition are very closely correlated. Herein, our data show that targeting MBD1 restored gallbladder cancer cell sensitivity to gemcitabine chemotherapy.

Conclusions

Taken together, the results of our study revealed a novel function of MBD1 in gallbladder cancer tumor development and progression through participation in the gallbladder cancer epithelial–mesenchymal transition program, which is involved in resistance to gemcitabine chemotherapy. Thus, MBD1 may be a potential therapeutic target for gallbladder cancer.

New Insights into the Role of Polybromo-1 in Prostate Cancer

The human protein Polybromo-1 (PBMR1/BAF180) is a component of the SWI/SNF chromatin-remodeling complex that has been reported to be deregulated in tumors. However, its role in prostate cancer (PCa) is largely unknown. In this study, we described the PBRM1 transcriptional levels and the protein expression/localization in tissues of PCa patients and in prostatic cell lines. Increased PBRM1 mRNA levels were found in PCa samples, when compared to benign disease, and were correlated with higher Gleason score. We also verified that only the nuclear localization of PBRM1 protein is correlated with a more aggressive disease and high Prostate-Specific Antigen (PSA) levels in tissue microarrays. Intriguing expression patterns of mRNA and protein were identified in the cell lines. Although PBRM1 protein was restricted to the nuclei, in tumor cell lines in non-neoplastic cells, it was also present in vesicular-like structures that were dispersed within the cytoplasm. We knocked-down PBRM1 in the castration-resistant PCa (CRPC) cell line PC-3 and we verified that PBRM1 promotes the expression of several markers of aggressiveness, including EpCAM, TGF-β, and N-Cadherin. Therefore, our data supported the hypothesis that PBRM1 displays a pivotal role in the promotion and maintenance of the malignant behavior of PCa, especially in CRPC.

A Role for βA3/A1-Crystallin in Type 2 EMT of RPE Cells Occurring in Dry Age-Related Macular Degeneration

Purpose

The RPE cells have a major role in the development of dry age-related macular degeneration (AMD). We present novel evidence that βA3/A1-crystallin, encoded by the Cryba1 gene, a protein known to be important for lysosomal clearance in the RPE, also has a role in epithelial-to-mesenchymal transition (EMT) of RPE cells.

Methods

RPE from dry AMD globes, genetically engineered mice lacking Cryba1 globally or specifically in the RPE, spontaneous mutant rats (Nuc1) with a loss-of-function mutation in Cryba1, and the melanoma OCM3 cell line were used. Spatial localization of proteins was demonstrated with immunofluorescence, gene expression levels were determined by quantitative PCR (qPCR), and protein levels by Western blotting. Cell movement was evaluated using wound healing and cell migration assays. Co-immunoprecipitation was used to identify binding partners of βA3/A1-crystallin.

Results

βA3/A1-crystallin is upregulated in polarized RPE cells compared to undifferentiated cells. Loss of βA3/A1-crystallin in murine and human RPE cells resulted in upregulation of Snail and vimentin, downregulation of E-cadherin, and increased cell migration. βA3/A1-crystallin binds to cortactin, and loss of βA3/A1-crystallin resulted in increased P-cortactin^Y421. The RPE from AMD samples had increased Snail and vimentin, and decreased E-cadherin, compared to age-matched controls.

Conclusions

We introduced a novel concept of dry AMD initiation induced by lysosomal clearance defects in the RPE and subsequent attempts by RPE cells to avoid the resulting stress by undergoing EMT. We demonstrate that βA3/A1-crystallin is a potential therapeutic target for AMD through rejuvenation of lysosomal dysfunction and potentially, reversal of EMT.

MicroRNA 628 suppresses migration and invasion of breast cancer stem cells through targeting SOS1

Purpose

The purpose of this study is to evaluate the effects of miR-628 on migration and invasion of breast cancer stem cells (CSCs), which are essential for tumor recurrence and metastasis.

Materials and methods

Quantitative reverse transcription-polymerase chain reaction was used to determine the expression of microRNAs and mRNAs. A subpopulation of CD44⁺/CD24⁻ breast CSCs were sorted by flow cytometry. Transwell assays were used to evaluate cell migration and invasion. Luciferase reporter assays were performed to verify whether miR-628 targeted SOS Ras/Rac guanine nucleotide exchange factor 1 (SOS1). pcDNA3.1(+)-SOS1 was constructed for overexpressing SOS1 after transfection.

Results

Compared with primary breast cancer cells, bone metastatic breast cancer cells showed significant downregulation of miR-628. The CD44⁺/CD24⁻ breast CSC subpopulations in MDA-MB-231 and MCF-7 cell lines were analyzed and sorted. Transfection with an miR-628 mimic significantly suppressed the migration and invasion of these breast CSCs by targeting SOS1, which plays an essential role in epithelial-to-mesenchymal transition. Overexpression of SOS1 rescued miR-628-mediated migration and invasion by upregulating Snail and vimentin, and downregulating E-cadherin.

Conclusion

miR-628 suppressed migration and invasion of breast CSCs of MDA-MB-231 and MCF-7 cells by directly targeting SOS1. Enhancement of miR-628 expression might be an effective strategy for managing breast cancer metastasis.