Tumor Microenvironment Versus Cancer Stem Cells in Cholangiocarcinoma: Synergistic Effects?

Systemic Treatment for Metastatic Biliary Tract Cancer: State of the Art and a Glimpse to the Future

Recent years have seen some breakthroughs in the therapeutic landscape of advanced biliary tract cancer (BTC). Firstly, a better understanding of the molecular background of BTC has led to important improvements in the management of these hepatobiliary malignancies, with the advent of targeted agents representing an unprecedented paradigm shift, as witnessed by the FDA approval of pemigatinib and infigratinib for FGFR2-rearranged and ivosidenib in IDH1-mutant cholangiocarcinoma. In addition, several novel treatments are under assessment, including immune checkpoint inhibitors and combination chemotherapies. In the current review, we provide an overview of systemic treatment for metastatic BTC, summarizing recent clinical data on chemotherapy as well as the main results of targeted therapies and immunotherapy.

PD-L1, TMB, MSI, and Other Predictors of Response to Immune Checkpoint Inhibitors in Biliary Tract Cancer

Biliary tract cancer (BTC) represents the second most frequently diagnosed primary liver cancer worldwide following hepatocellular carcinoma, and the overall survival of patients with unresectable disease remains poor. In recent years, the advent of immune checkpoint inhibitors (ICIs) has revolutionized the therapeutic landscape of several malignancies with these agents, which have also been explored in advanced BTC, as monotherapy or in combination with other anticancer agents. However, clinical trials evaluating ICIs in BTC have shown conflicting results, and the clinical benefit provided by immunotherapy seems limited to a small subgroup of BTC patients. Thus, the identification of reliable predictors of the response to immunotherapy represents a significant challenge in this setting. This review provides an overview of the available evidence on the biomarkers predictive of the response to ICIs in patients with advanced BTC, especially focusing on programmed death-ligand 1 (PD-L1), tumor mutational burden (TMB), microsatellite instability (MSI), and other emerging biomarkers.

Actinidia chinensis Planch prevents proliferation and migration of gastric cancer associated with apoptosis, ferroptosis activation and mesenchymal phenotype suppression

Actinidia chinensis Planch (ACP) was the kiwifruit plant Chinese kiwifruit Actinidia chinensis Planch Root, which had been approved to be an anti-tumor drug widespread in clinical. However, the specific mechanism of ACP in resistance to gastric cancer remained unclear. Therefore, our study was dedicated to investigate the anti-proliferation and anti-migration effects of ACP on gastric cancer cells and its molecular mechanisms. Firstly, we utilized HPLC-MS to analyze the composition of ACP decoction, the results showed that ACP contained two main anti-tumor components, Ursolic acid and Oleanolic acid. The proliferation and migration ability of HGC-27 were examined by CCK-8 and cell scratch tests respectively. In addition, we also investigated HGC-27 cells apoptosis, mesenchymal phenotype and ferroptosis after ACP rat drug-containing serum (ACPs) treatment. EGFP-expressing lentiviral vectors were utilized to construct HGC-27 cells which containing green fluorescence. Then we take advantages of containing green fluorescence cells to establish a zebrafish xenograft model in vivo. The CCK-8 and cell scratch experiments verified that ACPs significantly inhibited proliferation and migration of HGC-27 in vitro. ACPs increased cells apoptosis rate, while were rescued by apoptosis inhibitor Z-VAD-FMK. Furthermore, ACPs downregulated the expression levels of Vimentin protein and Snail protein markedly. Intriguingly, ACPs increased the accumulation of ROS via inhibited the glutathione peroxidase 4 (GPx4) and xCT (SLC7A11) proteins, while were inhibited by Ferrostatin-1 (Fer-1) significantly. Furthermore, the zebrafish xenograft study further confirmed that administration of ACP suppressed the xenograft growth and metastasis of transplanted HGC-27 cells in vivo. In conclusion, ACP was a promising antineoplastic agent for the treatment of gastric cancer by regulating apoptosis, ferroptosis and mesenchymal phenotype.

Role of Cancer Stem Cells in Cholangiocarcinoma and Therapeutic Implications

Cholangiocarcinoma (CCA) is the second most common type of liver cancer, and is highly aggressive with very poor prognosis. CCA is classified into intrahepatic cholangiocarcinoma (iCCA) and extra-hepatic cholangiocarcinoma (eCCA), which is further stratified into perihilar (pCCA) and distal (dCCA). Cancer stem cells (CSCs) are a subpopulation of cancer cells capable of tumor initiation and malignant growth, and are also responsible for chemoresistance. Thus, CSCs play an important role in CCA carcinogenesis. Surface markers such as CD133, CD24, CD44, EpCAM, Sox2, CD49f, and CD117 are important for identifying and isolating CCA CSCs. CSCs are present in the tumor microenvironment (TME), termed ‘CSC niche’, where cellular components and soluble factors interact to promote tumor initiation. Epithelial-to-mesenchymal transition (EMT) is another important mechanism underlying carcinogenesis, involved in the invasiveness, metastasis and chemoresistance of cancer. It has been demonstrated that EMT plays a critical role in generating CSCs. Therapies targeting the surface markers and signaling pathways of CCA CSCs, proteins involved in TME, and immune checkpoint proteins are currently under investigation. Therefore, this review focuses on recent studies on the roles of CSCs in CCA; the possible therapeutic strategies targeting CSCs of CCA are also discussed.

The Role of Oxidative Stress and Hormones in Controlling Obesity

The accumulation of adipose tissue in the body occurs because the energy introduced with food and drink exceeds that expense, but to understand why this imbalance is established and why it is maintained over time, it is important to consider the main causes and risk factors of excess weight. In this review, we will refer to the main factors linked to obesity, starting from oxidative stress to hormonal factors including the role of obesity in breast cancer. Among the many hypotheses formulated on the etiopathology of obesity, a key role can be attributed to the relationship between stress oxidative and intestinal microbiota. Multiple evidences tend to show that genetic, epigenetic, and lifestyle factors contribute to determine in the obese an imbalance of the redox balance correlated with the alteration of the intestinal microbial flora. Obesity acts negatively on the wound healing, in fact several studies indicate morbid obesity significantly increased the risk of a post-operative wound complication and infection. Currently, in the treatment of obesity, medical interventions are aimed not only at modifying caloric intake, but also to modulate and improve the composition of diet with the aim of rebalancing the microbiota-redox state axis.

MicroRNA-329-mediated PTTG1 downregulation inactivates the MAPK signaling pathway to suppress cell proliferation and tumor growth in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a severe malignancy usually producing a poor prognosis and high mortality rate. MicroRNAs (miRNAs) have been reported in association with CCA; however, the role miR-329 plays in the CCA condition still remains unclear. Therefore, this study was conducted to explore the underlying mechanism of which miR-329 is influencing the progression of CCA. This work studied the differential analysis of the expression chips of CCA obtained from the Gene Expression Omnibus database. Next, to determine both the expression and role of pituitary tumor transforming gene-1 (PTTG1) in CCA, the miRNAs regulating PTTG1 were predicted. In the CCA cells that had been intervened with miR-329 upregulation or inhibition, along with PTTG1 silencing, expression of miR-329, PTTG1, p-p38/p38, p-ERK5/ERK5, proliferating cell nuclear antigen (PCNA), Cyclin D1, Bcl-2-associated X protein (Bax), B-cell CLL/lymphoma 2 (Bcl-2), and caspase-3 were determined. The effects of both miR-329 and PTTG1 on cell proliferation, cell-cycle distribution, and apoptosis were also assayed. The miR-329 was likely to affect the CCA development through regulation of the PTTG1-mediated mitogen-activated protein kinase (MAPK) signaling pathway. The miR-329 targeted PTTG1, leading to inactivation of the MAPK signaling pathway. Upregulation of miR-329 and silencing of PTTG1 inhibited the CCA cell proliferation, induced cell-cycle arrest, and subsequently promoted apoptosis with elevations in Bax, cleaved caspase-3, and total caspase-3, but showed declines in PCNA, Cyclin D1, and Bcl-2. Moreover, miR-329 was also found to suppress the tumor growth by downregulation of PTTG1. To summarize, miR-329 inhibited the expression of PTTG1 to inactivate the MAPK signaling pathway, thus suppressing the CCA progression, thereby providing a therapeutic basis for the CCA treatment.

The role of tumour microenvironment: a new vision for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a relatively rare malignant and lethal tumour derived from bile duct epithelium and the morbidity is now increasing worldwide. This disease is difficult to diagnose at its inchoate stage and has poor prognosis. Therefore, a clear understanding of pathogenesis and major influencing factors is the key to develop effective therapeutic methods for CCA. In previous studies, canonical correlation analysis has demonstrated that tumour microenvironment plays an intricate role in the progression of various types of cancers including CCA. CCA tumour microenvironment is a dynamic environment consisting of authoritative tumour stromal cells and extracellular matrix where tumour stromal cells and cancer cells can thrive. CCA stromal cells include immune and non‐immune cells, such as inflammatory cells, endothelial cells, fibroblasts, and macrophages. Likewise, CCA tumour microenvironment contains abundant proliferative factors and can significantly impact the behaviour of cancer cells. Through abominably intricate interactions with CCA cells, CCA tumour microenvironment plays an important role in promoting tumour proliferation, accelerating neovascularization, facilitating tumour invasion, and preventing tumour cells from organismal immune reactions and apoptosis. This review summarizes the recent research progress regarding the connection between tumour behaviours and tumour stromal cells in CCA, as well as the mechanism underlying the effect of tumour stromal cells on the growth of CCA. A thorough understanding of the relationship between CCA and tumour stromal cells can shed some light on the development of new therapeutic methods for treating CCA.

Signal transduction growth factors: the effective governance of transcription and cellular adhesion in cancer invasion

Giulio Bizzozero classified the tissues concerning their capacity to self-renew during the adult life in labile, stable and permanent tissues. In 1940 Viktor Hamburger and Rita Levi Montalcini exposed the possibility to induce the growth of permanent cells thanks to a specific ligand Nerve Growth Factor (NGF). Stanley Cohen purified a protein the Epidermal Growth Factor (EGF), able to induce epidermis proliferation and to elicit precocious eye disclosure and teeth eruption, establishing the “inverse” relationships between the proliferation and differentiation. These two biological effects induced by EGF were according to EGFR signaling is involved in a large array of cellular functions such as proliferation, survival, adhesion, migration and differentiation. This review is focused on the key role of growth factors signaling and their downstream effectors in physiological and in pathological phenomena, the authors highlight the governance of Growth factors during the EMT in cancer invasion.

Decellularized colorectal cancer matrix as bioactive microenvironment for in vitro 3D cancer research

Three-dimensional (3D) cancer models are overlooking the scientific landscape with the primary goal of bridging the gaps between two-dimensional (2D) cell lines, animal models and clinical research. Here, we describe an innovative tissue engineering approach applied to colorectal cancer (CRC) starting from decellularized human biopsies in order to generate an organotypic 3D-bioactive model. This in vitro 3D system recapitulates the ultrastructural environment of native tissue as demonstrated by histology, immunohistochemistry, immunofluorescence and scanning electron microscopy analyses. Mass spectrometry of proteome and secretome confirmed a different stromal composition between decellularized healthy mucosa and CRC in terms of structural and secreted proteins. Importantly, we proved that our 3D acellular matrices retained their biological properties: using CAM assay, we observed a decreased angiogenic potential in decellularized CRC compared with healthy tissue, caused by direct effect of DEFA3. We demonstrated that following a 5 days of recellularization with HT-29 cell line, the 3D tumor matrices induced an over-expression of IL-8, a DEFA3-mediated pathway and a mandatory chemokine in cancer growth and proliferation. Given the biological activity maintained by the scaffolds after decellularization, we believe this approach is a powerful tool for future pre-clinical research and screenings.

Recent Advances in Understanding Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive malignancy that arises from damaged epithelial cells, cholangiocytes, and possibly de-differentiated hepatocytes. CCA has a poor overall survival rate and limited therapeutic options. Based on this data, it is imperative that new diagnostic and therapeutic interventions be developed. Recent work has attempted to understand the pathological mechanisms driving CCA progression. Specifically, recent publications have delved into the role of cancer stem cells (CSCs), mesenchymal stem cells (MSCs), and microRNAs (miRNAs) during CCA pathology. CSCs are a specific subset of cells within the tumor environment that are derived from a cell with stem-like properties and have been shown to influence recurrence and chemoresistance during CCA. MSCs are known for their anti-inflammatory activity and have been postulated to influence malignancy during CCA, but little is known about their exact functions. miRNAs exert various functions via gene regulation at both the transcriptional and the translational levels, giving miRNAs diverse roles in CCA progression. Additionally, current miRNA-based therapeutic approaches are in clinical trials for various liver diseases, giving hope for similar approaches for CCA. However, the interactions among these three factors in the context of CCA are unknown. In this review, we focus on recently published data (within the last 3 years) that discuss the role of CSCs, MSCs, and miRNAs and their possible interactions during CCA pathogenesis.

Participation of CCL1 in Snail-Positive Fibroblasts in Colorectal Cancer Contribute to 5-Fluorouracil/Paclitaxel Chemoresistance

Purpose

Cancer-associated fibroblasts (CAFs) activated by cancer cells has a central role in development and malignant biological behavior in colorectal cancer (CRC). Adult fibroblasts do not express Snail, but Snail-positive fibroblasts are discovered in the stroma of malignant CRC and reported to be the key role to chemoresistance. However, the reciprocal effect of CAFs expressed Snail to chemoresistance on CRC cells and the underlying molecular mechanisms are not fully characterized.

Materials and Methods

Snail-overexpressed 3T3 stable cell lines were generated by lipidosome and CT26 mixed with 3T3-Snail subcutaneous transplanted CRC models were established by subcutaneous injection. Cell Counting Kit-8, flow cytometry and western blotting assays were performed, and immunohistochemistry staining was studied. The cytokines participated in chemoresistance was validated with reverse transcriptase-polymerase chain reaction and heatmap.

Results

Snail-expression fibroblasts are discovered in human and mouse spontaneous CRCs. Overexpression of Snail induces 3T3 fibroblasts transdifferentiation to CAFs. CT26 co-cultured with 3T3-Snail resisted the impairment from 5-fluorouracil and paclitaxel in vitro. The subcutaneous transplanted tumor models included 3T3-Snail cells develop without restrictions even after treating with 5-fluorouracil or paclitaxel. Moreover, these chemoresistant processes may be mediated by CCL1 secreted by Snail-expression fibroblasts via transforming growth factor β/nuclear factor-κB signaling pathways.

Conclusion

Taken together, Snail-expressing 3T3 fibroblasts display CAFs properties that support 5-fluorouracil and paclitaxel chemoresistance in CRC via participation of CCL1 and suggest that inhibition of the Snail-expression fibroblasts in tumor may be a useful strategy to limit chemoresistance.

Biliary tract cancer stem cells - translational options and challenges

Management of biliary tract cancer remains challenging. Tumors show high recurrence rates and therapeutic resistance, leading to dismal prognosis and short survival. The cancer stem cell model states that a tumor is a heterogeneous conglomerate of cells, in which a certain subpopulation of cells - the cancer stem cells - possesses stem cell properties. Cancer stem cells have high clinical relevance due to their potential contributions to development, progression and aggressiveness as well as recurrence and metastasis of malignant tumors. Consequently, reliable identification of as well as pharmacological intervention with cancer stem cells is an intensively investigated and promising research field. The involvement of cancer stem cells in biliary tract cancer is likely as a number of studies demonstrated their existence and the obvious clinical relevance of several established cancer stem cell markers in biliary tract cancer models and tissues. In the present article, we review and discuss the currently available literature addressing the role of putative cancer stem cells in biliary tract cancer as well as the connection between known contributors of biliary tract tumorigenesis such as oncogenic signaling pathways, micro-RNAs and the tumor microenvironment with cancer stem cells.

Signaling pathways as therapeutic targets in biliary tract cancer

INTRODUCTION

The incidence of biliary tract cancer (BTC) is increasing, and the disease is frequently diagnosed during advanced stages, leading to poor overall survival. Limited treatment options are currently available and novel therapeutic approaches are needed. A number of completed clinical trials have evaluated the role of chemotherapy for BTC, demonstrating a marginal benefit. Thus, there is increased interest in applying targeted therapies for this disease. Areas covered: This review article summarizes the role of chemotherapeutic regimens for the treatment of BTC, and highlights key signal transduction pathways of interest for targeted inhibition. Of particular interest are the MEK or MAP2K (mitogen-activated protein kinase kinase), phosphatidylinositol-3 kinase (PI3K) and signal transducer and activator of transcription-3 (STAT3) pathways. We discuss the available data on several promising inhibitors of these pathways, both in the pre-clinical and clinical settings. Expert opinion: Future treatment strategies should address targeting of MEK, PI3K and STAT3 for BTC, with a focus on combined therapeutic approaches.

Fibroblast-led cancer cell invasion is activated by epithelial-mesenchymal transition through platelet-derived growth factor BB secretion of lung adenocarcinoma

Cancer-associated fibroblast (CAF)-dependent local invasion is the process by which cancer cells invade the extracellular matrix using tracks that have been physically remodeled by CAFs. In the present study, we investigated the process by which the epithelial-mesenchymal transition (EMT) of cancer cells affect CAF-dependent local invasion. Using an in vitro collagen invasion assay, we showed cancer cells undergoing EMT to promote the matrix-remodeling ability of CAFs and thereby enhance CAF-dependent local cancer cell invasion. Platelet-derived growth factor (PDGF)-BB secretion was significantly elevated in cancer cells undergoing EMT, and this induced an increase in the invasion ability of both CAFs and cancer cells. Conversely, knockdown of PDGF-B expression in cancer cells undergoing EMT, or treatment with a PDGF-receptor inhibitor, decreased the invasion ability of both CAFs and cancer cells. By analyzing the gene expression profiles of 442 patients with lung adenocarcinomas, we established that high expression of PDGF-B and presentation of mesenchymal-like tumors were significantly associated with a high rate of disease recurrence and poor patient prognosis. Thus, cancer cells undergoing EMT may accelerate their own ability to invade local tissues via PDGF-BB secretion to promote CAF matrix remodeling. Therefore, targeting PDGF signaling between cancer cells undergoing EMT and CAFs is a promising therapeutic target to inhibit cancer progression and improve patient prognosis.

Cocktail treatment with EGFR-specific and CD133-specific chimeric antigen receptor-modified T cells in a patient with advanced cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is one of the most fatal malignant tumors with increasing incidence, mortality, and insensitivity to traditional chemo-radiotherapy and targeted therapy. Chimeric antigen receptor-modified T cell (CART) immunotherapy represents a novel strategy for the management of many malignancies. However, the potential of CART therapy in treating advanced unresectable/metastatic CCA is uncharted so far.

CASE PRESENTATION

In this case, a 52-year-old female who was diagnosed as advanced unresectable/metastatic CCA and resistant to the following chemotherapy and radiotherapy was treated with CART cocktail immunotherapy, which was composed of successive infusions of CART cells targeting epidermal growth factor receptor (EGFR) and CD133, respectively. The patient finally achieved an 8.5-month partial response (PR) from the CART-EGFR therapy and a 4.5-month-lasting PR from the CART133 treatment. The CART-EGFR cells induced acute infusion-related toxicities such as mild chills, fever, fatigue, vomiting and muscle soreness, and a 9-day duration of delayed lower fever, accompanied by escalation of IL-6 and C reactive protein (CRP), acute increase of glutamic-pyruvic transaminase and glutamic-oxalacetic transaminase, and grade 2 lichen striatus-like skin pathological changes. The CART133 cells induced an intermittent upper abdominal dull pain, chills, fever, and rapidly deteriorative grade 3 systemic subcutaneous hemorrhages and congestive rashes together with serum cytokine release, which needed emergent medical intervention including intravenous methylprednisolone.

CONCLUSIONS

This case suggests that CART cocktail immunotherapy may be feasible for the treatment of CCA as well as other solid malignancies; however, the toxicities, especially the epidermal/endothelial damages, require a further investigation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01869166 and NCT02541370 .

The role of ADAM17 in tumorigenesis and progression of breast cancer

A disintegrin and metalloproteinase (ADAM) family members are known to process the target membrane-bound molecules through the quick induction of their protease activities under interaction with other molecules, which have diverse roles in tissue morphogenesis and pathophysiological remodeling. Among these, ADAM17 is a membrane-bound protease that sheds the extracellular domain of various receptors or its ligands from the cell membrane and subsequently activates downstream signaling transduction pathways. Importantly, breast cancer remains a mainspring of cancer-induced death in women, and numerous regulatory pathways have been implicated in the formation of breast cancer. Substantial evidence has demonstrated that an obvious increased in ADAM17 cell surface expression has been discovered in breast cancer and was shown to be associated with mammary tumorigenesis, invasiveness, and drug resistance. Over the last decades, it has received more than its share of attention that ADAM17 plays a potential role in breast cancer, including cell proliferation, invasion, angiogenesis, apoptosis, and trastuzumab resistance. In our review, we discuss the mechanisms through which ADAM17 acts on breast cancer tumorigenesis and progression. Thus, this will provide further impetus for exploiting ADAM17 as a new target for breast cancer treatment.

3,6-dihydroxyflavone suppresses the epithelial-mesenchymal transition in breast cancer cells by inhibiting the Notch signaling pathway

The epithelial to mesenchymal transition (EMT) is a critical developmental program in cancer stem cell (CSC) maintenance and in cancer metastasis. Here, our study found that 3,6-DHF could effectively inhibit EMT in BC cells in vitro and in vivo. 3,6-DHF effectively inhibits the formation and proliferation of BCSCs, and consequently reduces the tumor-initiating capacity of tumor cells in NOD/SCID mice. Optical in vivo imaging of cancer metastasis showed that 3,6-DHF administration suppresses the lung metastasis of BC cells in vivo. Further studies indicated that 3,6-DHF down-regulates Notch1, NICD, Hes-1 and c-Myc, consequently decreasing the formation of the functional transcriptional unit of NICD-CSL-MAML, causing Notch signaling inactivation in BC cells. Over-expression of Notch1 or inhibition of miR-34a significantly reduced the inhibitory effects of 3,6-DHF on EMT, CSCs, as well as cells migration and invasion in BC cells. These data indicated that 3,6-DHF effectively inhibits EMT and CSCs, as well as cells migration and invasion in BC cells, in which miR-34a-mediated Notch1 down-regulation plays a crucial role.