IL-22 regulates MASTL expression in intestinal epithelial cells.

Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as a oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic CRC and colitis associated cancer (CAC). CAC is one of the most severe complications of chronic IBD, but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL expression in IBD patients and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from late-stage ulcerative colitis patients compared to controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, facilitating IL-22- mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Further, CAIX stabilizes MASTL by associating with it in response to IL-22 stimulation.

Albendazole inhibits colon cancer progression and therapy resistance by targeting ubiquitin ligase RNF20.

BACKGROUND: The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality. METHODS: High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs). RESULTS: Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription. CONCLUSIONS: Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.

Loss of claudin-3 expression increases colitis risk by promoting Gut Dysbiosis.

Dysregulation of both the gut barrier and microbiota (dysbiosis) promotes susceptibility to and severity of Inflammatory Bowel Diseases (IBD). Leaky gut and dysbiosis often coexist; however, potential interdependence and molecular regulation are not well understood. Robust expression of claudin-3 (CLDN3) characterizes the gut epithelium, and studies have demonstrated a positive association between CLDN3 expression and gut barrier maturity and integrity, including in response to probiotics. However, the exact status and causal role of CLDN3 in IBD and regulation of gut dysbiosis remain unknown. Analysis of mouse and human IBD cohorts helped examine CLDN3 expression in IBD. The causal role was determined by modeling CLDN3 loss of expression during experimental colitis. 16S sequencing and in silico analysis helped examine gut microbiota diversity between Cldn3KO and WT mice and potential host metabolic responses. Fecal microbiota transplant (FMT) studies were performed to assess the role of gut dysbiosis in the increased susceptibility of Cldn3KO mice to colitis. A significant decrease in CLDN3 expression characterized IBD and CLDN3 loss of expression promoted colitis. 16S sequencing analysis suggested gut microbiota changes in Cldn3KO mice that were capable of modulating fatty acid metabolism and oxidative stress response. FMT from naïve Cldn3KO mice promoted colitis susceptibility in recipient germ-free mice (GFM) compared with GFM-receiving microbiota from WT mice. Our data demonstrate a critical role of CLDN3 in maintaining normal gut microbiota and inflammatory responses, which can be harnessed to develop novel therapeutic opportunities for patients with IBD.

Claudin-1 interacts with EPHA2 to promote cancer stemness and chemoresistance in colorectal cancer.

Therapy resistance is the primary problem in treating late-stage colorectal cancer (CRC). Claudins are frequently dysregulated in cancer, and several are being investigated as novel therapeutic targets and biomarkers. We have previously demonstrated that Claudin-1 (CLDN1) expression in CRC promotes epithelial-mesenchymal transition, metastasis, and resistance to anoikis. Here, we hypothesize that CLDN1 promotes cancer stemness and chemoresistance in CRC. We found that high CLDN1 expression in CRC is associated with cancer stemness and chemoresistance signaling pathways in patient datasets, and it promotes chemoresistance both in vitro and in vivo. Using functional stemness assays, proteomics, biophysical binding assays, and patient-derived organoids, we found that CLDN1 promotes properties of cancer stemness including CD44 expression, tumor-initiating potential, and chemoresistance through a direct interaction with ephrin type-A receptor 2 (EPHA2) tyrosine kinase. This interaction is dependent on the CLDN1 PDZ-binding motif, increases EPHA2 protein expression by inhibiting its degradation, and enhances downstream AKT signaling and CD44 expression to promote stemness and chemoresistance. These results suggest CLDN1 is a viable target for pharmacological intervention and/or biomarker development.

Claudin-2 protects against colitis-associated cancer by promoting colitis-associated mucosal healing.

Patients with inflammatory bowel disease (IBD) are susceptible to colitis-associated cancer (CAC). Chronic inflammation promotes the risk for CAC. In contrast, mucosal healing predicts improved prognosis in IBD and reduced risk of CAC. However, the molecular integration among colitis, mucosal healing, and CAC remains poorly understood. Claudin-2 (CLDN2) expression is upregulated in IBD; however, its role in CAC is not known. The current study was undertaken to examine the role for CLDN2 in CAC. The AOM/DSS-induced CAC model was used with WT and CLDN2-modified mice. High-throughput expression analyses, murine models of colitis/recovery, chronic colitis, ex vivo crypt culture, and pharmacological manipulations were employed in order to increase our mechanistic understanding. The Cldn2KO mice showed significant inhibition of CAC despite severe colitis compared with WT littermates. Cldn2 loss also resulted in impaired recovery from colitis and increased injury when mice were subjected to intestinal injury by other methods. Mechanistic studies demonstrated a possibly novel role of CLDN2 in promotion of mucosal healing downstream of EGFR signaling and by regulation of Survivin expression. An upregulated CLDN2 expression protected from CAC and associated positively with crypt regeneration and Survivin expression in patients with IBD. We demonstrate a potentially novel role of CLDN2 in promotion of mucosal healing in patients with IBD and thus regulation of vulnerability to colitis severity and CAC, which can be exploited for improved clinical management.

Repeated Social Defeat Stress Induces an Inflammatory Gut Milieu by Altering the Mucosal Barrier Integrity and Gut Microbiota Homeostasis.

Background: Posttraumatic stress disorder (PTSD) is a mental health condition triggered by exposure to traumatic events in an individual's life. Patients with PTSD are also at a higher risk for comorbidities. However, it is not well understood how PTSD affects human health and/or promotes the risk for comorbidities. Nevertheless, patients with PTSD harbor a proinflammatory milieu and dysbiotic gut microbiota. Gut barrier integrity helps to maintain normal gut homeostasis and its dysregulation promotes gut dysbiosis and inflammation. Methods: We used a mouse model of repeated social defeat stress (RSDS), a preclinical model of PTSD. Behavioral studies, metagenomics analysis of the microbiome, gut permeability assay (on mouse colon, using an Ussing chamber), immunoblotting, and immunohistochemical analyses were performed. Polarized intestinal epithelial cells and 3-dimensional crypt cultures were used for mechanistic analysis. Results: The RSDS mice harbor a heightened proinflammatory gut environment and microbiota dysbiosis. The RSDS mice further showed significant dysregulation of gut barrier functions, including transepithelial electrical resistance, mucin homeostasis, and antimicrobial responses. RSDS mice also showed a specific increase in intestinal expression of claudin-2, a tight junction protein, and epinephrine, a stress-induced neurotransmitter. Treating intestinal epithelial cells or 3-dimensional cultured crypts with norepinephrine or intestinal luminal contents (fecal contents) upregulated claudin-2 expression and inhibited transepithelial electrical resistance. Conclusions: Traumatic stress induces dysregulation of gut barrier functions, which may underlie the observed gut microbiota changes and proinflammatory gut milieu, all of which may have an interdependent effect on the health and increased risk of comorbidities in patients with PTSD.

Pyrroline-5-Carboxylate Reductase-2 Promotes Colorectal Carcinogenesis by Modulating Microtubule-Associated Serine/Threonine Kinase-like/Wnt/ß-Catenin Signaling.

BACKGROUND: Despite significant progress in clinical management, colorectal cancer (CRC) remains the third most common cause of cancer-related deaths. A positive association between PYCR2 (pyrroline-5-carboxylate reductase-2), a terminal enzyme of proline metabolism, and CRC aggressiveness was recently reported. However, how PYCR2 promotes colon carcinogenesis remains ill understood. METHODS: A comprehensive analysis was performed using publicly available cancer databases and CRC patient cohorts. Proteomics and biochemical evaluations were performed along with genetic manipulations and in vivo tumor growth assays to gain a mechanistic understanding. RESULTS: PYCR2 expression was significantly upregulated in CRC and associated with poor patient survival, specifically among PYCR isoforms (PYCR1, 2, and 3). The genetic inhibition of PYCR2 inhibited the tumorigenic abilities of CRC cells and in vivo tumor growth. Coinciding with these observations was a significant decrease in cellular proline content. PYCR2 overexpression promoted the tumorigenic abilities of CRC cells. Proteomics (LC-MS/MS) analysis further demonstrated that PYCR2 loss of expression in CRC cells inhibits survival and cell cycle pathways. A subsequent biochemical analysis supported the causal role of PYCR2 in regulating CRC cell survival and the cell cycle, potentially by regulating the expression of MASTL, a cell-cycle-regulating protein upregulated in CRC. Further studies revealed that PYCR2 regulates Wnt/ß-catenin-signaling in manners dependent on the expression of MASTL and the cancer stem cell niche. CONCLUSIONS: PYCR2 promotes MASTL/Wnt/ß-catenin signaling that, in turn, promotes cancer stem cell populations and, thus, colon carcinogenesis. Taken together, our data highlight the significance of PYCR2 as a novel therapeutic target for effectively treating aggressive colon cancer.

P62/SQSTM1 binds with claudin-2 to target for selective autophagy in stressed intestinal epithelium.

Impaired autophagy promotes Inflammatory Bowel Disease (IBD). Claudin-2 is upregulated in IBD however its role in the pathobiology remains uncertain due to its complex regulation, including by autophagy. Irrespective, claudin-2 expression protects mice from DSS colitis. This study was undertaken to examine if an interplay between autophagy and claudin-2 protects from colitis and associated epithelial injury. Crypt culture and intestinal epithelial cells (IECs) are subjected to stress, including starvation or DSS, the chemical that induces colitis in-vivo. Autophagy flux, cell survival, co-immunoprecipitation, proximity ligation assay, and gene mutational studies are performed. These studies reveal that under colitis/stress conditions, claudin-2 undergoes polyubiquitination and P62/SQSTM1-assisted degradation through autophagy. Inhibiting autophagy-mediated claudin-2 degradation promotes cell death and thus suggest that claudin-2 degradation promotes autophagy flux to promote cell survival. Overall, these data inform for the previously undescribed role for claudin-2 in facilitating IECs survival under stress conditions, which can be harnessed for therapeutic advantages.

Mucosal healing and inflammatory bowel disease: Therapeutic implications and new targets.

Mucosal healing (MH) is vital in maintaining homeostasis within the gut and protecting against injury and infections. Multiple factors and signaling pathways contribute in a dynamic and coordinated manner to maintain intestinal homeostasis and mucosal regeneration/repair. However, when intestinal homeostasis becomes chronically disturbed and an inflammatory immune response is constitutively active due to impairment of the intestinal epithelial barrier autoimmune disease results, particularly inflammatory bowel disease (IBD). Many proteins and signaling pathways become dysregulated or impaired during these pathological conditions, with the mechanisms of regulation just beginning to be understood. Consequently, there remains a relative lack of broadly effective therapeutics that can restore MH due to the complexity of both the disease and healing processes, so tissue damage in the gastrointestinal tract of patients, even those in clinical remission, persists. With increased understanding of the molecular mechanisms of IBD and MH, tissue damage from autoimmune disease may in the future be ameliorated by developing therapeutics that enhance the body's own healing response. In this review, we introduce the concept of mucosal healing and its relevance in IBD as well as discuss the mechanisms of IBD and potential strategies for altering these processes and inducing MH.

Identification and characterization of a first-generation inhibitor of claudin-1 in colon cancer progression and metastasis.

Colorectal cancer (CRC) is a leading cause of the cancer-related deaths worldwide. Thus, developing novel and targeted therapies for inhibiting CRC progression and metastasis is urgent. Several studies, including ours, have reported a causal role for an upregulated claudin-1 expression in promoting CRC metastasis through the activation of the Src and ß-catenin-signaling. In murine models of colon tumorigenesis, claudin-1 overexpression promotes oncogenic properties such as transformation and invasiveness. Conversely, the downregulation of claudin-1 inhibits colon tumorigenesis. Despite being a desirable target for cancer treatment, there are currently no known claudin-1 inhibitors with antitumor efficacy. Using a rigorous analytical design and implementing in- vitro and in-vivo testing and a brief medicinal chemistry campaign, we identified a claudin-1-specific inhibitor and named it I-6. Despite its high potency, I-6 was rapidly cleared in human liver microsomes. We, therefore, synthesized I-6 analogs and discovered a novel small molecule, PDS-0330. We determined that PDS0330 inhibits claudin-1-dependent CRC progression without exhibiting toxicity in in-vitro and in-vivo models of CRC and that it binds directly and specifically to claudin-1 with micromolar affinity. Further analyses revealed that PDS-0330 exhibits antitumor and chemosensitizer activities with favorable pharmacokinetic properties by inhibiting the association with metastatic oncogene Src. Overall, our data propose that PDS-0330 interferes with claudin-1/Src association to inhibit CRC progression and metastasis. Our findings are of direct clinical relevance and may open new therapeutic opportunities in colon cancer treatment and/or management by targeting claudin-1.

Piglet cardiopulmonary bypass induces intestinal dysbiosis and barrier dysfunction associated with systemic inflammation.

The intestinal microbiome is essential to human health and homeostasis, and is implicated in the pathophysiology of disease, including congenital heart disease and cardiac surgery. Improving the microbiome and reducing inflammatory metabolites may reduce systemic inflammation following cardiac surgery with cardiopulmonary bypass (CPB) to expedite recovery post-operatively. Limited research exists in this area and identifying animal models that can replicate changes in the human intestinal microbiome after CPB is necessary. We used a piglet model of CPB with two groups, CPB (n=5) and a control group with mechanical ventilation (n=7), to evaluate changes to the microbiome, intestinal barrier dysfunction and intestinal metabolites with inflammation after CPB. We identified significant changes to the microbiome, barrier dysfunction, intestinal short-chain fatty acids and eicosanoids, and elevated cytokines in the CPB/deep hypothermic circulatory arrest group compared to the control group at just 4 h after intervention. This piglet model of CPB replicates known human changes to intestinal flora and metabolite profiles, and can be used to evaluate gut interventions aimed at reducing downstream inflammation after cardiac surgery with CPB.

Oral Delivery of Nucleic Acid Therapies for Local and Systemic Action.

Nucleic acid (NA) therapy has gained importance over the past decade due to its high degree of selectivity and minimal toxic effects over conventional drugs. Currently, intravenous (IV) or intramuscular (IM) formulations constitute majority of the marketed formulations containing nucleic acids. However, oral administration is traditionally preferred due to ease of administration as well as higher patient compliance. To leverage the benefits of oral delivery for NA therapy, the NA of interest must be delivered to the target site avoiding all degrading and inhibiting factors during its transition through the gastrointestinal tract. The oral route presents myriad of challenges to NA delivery, making formulation development challenging. Researchers in the last few decades have formulated various delivery systems to overcome such challenges and several reviews summarize and discuss these strategies in detail. However, there is a need to differentiate between the approaches based on target so that in future, delivery strategies can be developed according to the goal of the study and for efficient delivery to the desired site. The goal of this review is to summarize the mechanisms for target specific delivery, list and discuss the formulation strategies used for oral delivery of NA therapies and delineate the similarities and differences between local and systemic targeting oral delivery systems and current challenges.

The diet-microbiota axis: a key regulator of intestinal permeability in human health and disease.

The intestinal barrier orchestrates selective permeability to nutrients and metabolites while excluding noxious stimuli. Recent scientific advances establishing a causal role for the gut microbiota in human health outcomes have generated a resurgent interest toward intestinal permeability. Considering the well-established role of the gut barrier in protection against foreign antigens, there is mounting evidence for a causal link between gut permeability and the microbiome in regulating human health. However, an understanding of the dynamic host-microbiota interactions that govern intestinal barrier functions remains poorly defined. Furthermore, the system-level mechanisms by which microbiome-targeted therapies, such as probiotics and prebiotics, simultaneously promote intestinal barrier function and host health remain an area of active investigation. This review summarizes the recent advances in understanding the dynamics of intestinal permeability in human health and its integration with gut microbiota. We further summarize mechanisms by which probiotics/prebiotics influence the gut microbiota and intestinal barrier functions.

Reliable epithelial-mesenchymal transition biomarkers for colorectal cancer detection.

Aims: To combat increases in colorectal cancer (CRC) incidence and mortality, biomarkers among differentially expressed genes (DEGs) have been identified to objectively detect cancer. However, DEGs are numerous, and additional parameters may identify more reliable biomarkers. Here, CRC DEGs were filtered into a prioritized list of biomarkers. Materials & methods: Two independent datasets (COAD-READ [n = 698] and GSE50760 [n = 36]) were input alternatively to the recently published data-driven reference method. Results were filtered based on epithelial-mesenchymal transition enrichment (χ-square statistic: 919.05; p = 2.2e-16) to produce 37 potential CRC biomarkers. Results: All 37 genes reliably classified CRC samples and ETV4, CLDN1 and CA2 together were top-ranked by DDR (accuracy: 89%; F1 score: 0.89). Conclusion: Biological and statistical information were combined to produce a better set of CRC detection biomarkers.

Identification of Immunoglobulin G Autoantibody Against Malondialdehyde-Acetaldehyde Adducts as a Novel Serological Biomarker for Ulcerative Colitis.

INTRODUCTION: Inflammatory bowel disease (IBD) is associated with immune responses with oxidative stress wherein high levels of malondialdehyde result in the formation of a highly stable and immunogenic malondialdehyde-acetaldehyde adduct (MAA). Thus, this study evaluated the status of MAA and anti-MAA antibody isotypes in IBD and their potential as novel serological biomarkers for differentiating ulcerative colitis (UC) from Crohn's disease (CD). METHODS: Levels of MAA and anti-MAA antibodies were examined in patients with IBD (171), non-IBD gastrointestinal diseases (77), and controls (83) from 2 independent cohorts using immunohistochemistry and enzyme-linked immunosorbent assay. Receiver operating characteristic curves and Youden cutoff index from logistic regression were used to determine the sensitivity and specificity. RESULTS: The MAA and blood immunoglobulin G (IgG) anti-MAA antibody levels were significantly elevated in IBD compared with non-IBD patients (P = 0.0008) or controls (P = 0.02). Interestingly, patients with UC showed higher levels of IgG anti-MAA (P < 0.0001) than patients with CD including those with colonic CD (P = 0.0067). The odds ratio by logistic regression analysis predicted stronger association of IgG anti-MAA antibody with UC than CD. Subsequent analysis showed that IgG anti-MAA antibody levels could accurately identify (P = 0.0004) UC in the adult cohort with a sensitivity of 75.3% and a specificity of 71.4% and an area under the curve of 0.8072 (0.7121-0.9024). The pediatric cohort also showed an area under the curve of 0.8801 (0.7988-0.9614) and precisely distinguished (P < 0.0001) UC with sensitivity (95.8%) and specificity (72.3%). DISCUSSION: Circulating IgG anti-MAA antibody levels can serve as a novel, noninvasive, and highly sensitive test to identify patients with UC and possibly differentiate them from patients with CD.

A Claudin-Based Molecular Signature Identifies High-Risk, Chemoresistant Colorectal Cancer Patients.

Identifying molecular characteristics that are associated with aggressive cancer phenotypes through gene expression profiling can help predict treatment responses and clinical outcomes. Claudins are deregulated in colorectal cancer (CRC). In CRC, increased claudin-1 expression results in epithelial-to-mesenchymal transition and metastasis, while claudin-7 functions as a tumor suppressor. In this study, we have developed a molecular signature based on claudin-1 and claudin-7 associated with poor patient survival and chemoresistance. This signature was validated using an integrated approach including publicly available datasets and CRC samples from patients who either responded or did not respond to standard-of-care treatment, CRC cell lines, and patient-derived rectal and colon tumoroids. Transcriptomic analysis from a patient dataset initially yielded 23 genes that were differentially expressed along with higher claudin-1 and decreased claudin-7. From this analysis, we selected a claudins-associated molecular signature including PIK3CA, SLC6A6, TMEM43, and ASAP-1 based on their importance in CRC. The upregulation of these genes and their protein products was validated using multiple CRC patient datasets, in vitro chemoresistant cell lines, and patient-derived tumoroid models. Additionally, blocking these genes improved 5-FU sensitivity in chemoresistant CRC cells. Our findings propose a new claudin-based molecular signature that associates with poor prognosis as well as characteristics of treatment-resistant CRC including chemoresistance, metastasis, and relapse.

Colonoscopy-based intramucosal transplantation of cancer cells for mouse modeling of colon cancer and lung metastasis.

The conventional orthotopic/xenograft models or genetically engineered murine models of colon cancer (CRC) are limited in their scope for a true understanding of tumor growth, progression and eventual metastasis in its natural microenvironment. In the currently used murine models of CRC metastasis, the metastasis occurs primarily in the liver, though lung metastasis accounts for a significant proportion of CRC metastasis. There is an urgent need for a murine model of CRC, which not only allows tumor progression in the colonic mucosa but also metastasis of the lung. The authors describe a minimally invasive murine model of colon cancer progression that may be ideal for a wide range of applications, including evaluating gene function, microenvironment, cancer metastasis and therapeutic translational research.

MASTL regulates EGFR signaling to impact pancreatic cancer progression.

Pancreatic cancer (PC) remains a major cause of cancer-related deaths primarily due to its inherent potential of therapy resistance. Checkpoint inhibitors have emerged as promising anti-cancer agents when used in combination with conventional anti-cancer therapies. Recent studies have highlighted a critical role of the Greatwall kinase (microtubule-associated serine/threonine-protein kinase-like (MASTL)) in promoting oncogenic malignancy and resistance to anti-cancer therapies; however, its role in PC remains unknown. Based on a comprehensive investigation involving PC patient samples, murine models of PC progression (Kras;PdxCre-KC and Kras;p53;PdxCre-KPC), and loss and gain of function studies, we report a previously undescribed critical role of MASTL in promoting cancer malignancy and therapy resistance. Mechanistically, MASTL promotes PC by modulating the epidermal growth factor receptor protein stability and, thereupon, kinase signaling. We further demonstrate that combinatorial therapy targeting MASTL promotes the efficacy of the cell-killing effects of Gemcitabine using both genetic and pharmacological inhibitions. Taken together, this study identifies a key role of MASTL in promoting PC progression and its utility as a novel target in promoting sensitivity to the anti-PC therapies.

Dysbiosis and Intestinal Barrier Dysfunction in Pediatric Congenital Heart Disease Is Exacerbated Following Cardiopulmonary Bypass.

There are no data evaluating the microbiome in congenital heart disease following cardiopulmonary bypass. The authors evaluated patients with congenital heart disease undergoing cardiopulmonary bypass and noncardiac patients undergoing surgery without bypass. Patients with congenital heart disease had differences in baseline microbiome compared with control subjects, and this was exacerbated following surgery with bypass. Markers of barrier dysfunction were similar for both groups at baseline, and surgery with bypass induced significant intestinal barrier dysfunction compared with control subjects. This study offers novel evidence of alterations of the microbiome in congenital heart disease and exacerbation along with intestinal barrier dysfunction following cardiopulmonary bypass.

Pancreatic Cancer and Therapy: Role and Regulation of Cancer Stem Cells.

Despite significant improvements in clinical management, pancreatic cancer (PC) remains one of the deadliest cancer types, as it is prone to late detection with extreme metastatic properties. The recent findings that pancreatic cancer stem cells (PaCSCs) contribute to the tumorigenesis, progression, and chemoresistance have offered significant insight into the cancer malignancy and development of precise therapies. However, the heterogeneity of cancer and signaling pathways that regulate PC have posed limitations in the effective targeting of the PaCSCs. In this regard, the role for K-RAS, TP53, Transforming Growth Factor-ß, hedgehog, Wnt and Notch and other signaling pathways in PC progression is well documented. In this review, we discuss the role of PaCSCs, the underlying molecular and signaling pathways that help promote pancreatic cancer development and metastasis with a specific focus on the regulation of PaCSCs. We also discuss the therapeutic approaches that target different PaCSCs, intricate mechanisms, and therapeutic opportunities to eliminate heterogeneous PaCSCs populations in pancreatic cancer.