Molecular Pathways: Mucins and Drug Delivery in Cancer

Integrative bioinformatics analysis reveals ECM and nicotine-related genes in both LUAD and LUSC, but different lung fibrosis-related genes are involved in LUAD and LUSC

There are several bioinformatics studies related to lung cancer, but most of them have mainly focused on either microarray data or RNA-Seq data alone. In this study, we have combined both types of data to identify differentially expressed genes (DEGs) specific to lung cancer subtypes. We obtained six microarray datasets from the GEO and also the expression matrix of LUSC and LUAD from TCGA, which were analyzed by GEO2R tool and GEPIA2, respectively. Enrichment analyses of DEGs were performed using the Enrichr database. Protein module identification was done by MCODE plugin in cytoscape software. We identified 30 LUAD-specific, 17 LUSC-specific, and 17 DEGs shared between LUAD and LUSC. Enrichment analyses revealed that LUSC-specific DEGs are involved in lung fibrosis. In addition, DEGs shared between LUAD and LUSC are involved in extracellular matrix (ECM), nicotine metabolism, and lung fibrosis. We identified lung fibrosis-related genes, including SPP1, MMP9, and CXCL2, involved in both LUAD and LUSC, but SERPINA1 and PLAU genes involved only in LUSC. We also found an important module separately for LUAD-specific, LUSC-specific, and shared DEGs between LUSC and LUAD. S100P, GOLM, AGR2, AK1, TMEM125, SLC2A1, COL1A1, and GHR genes were significantly associated with survival. Our findings suggest that different lung fibrosis-related genes may play roles in LUSC and LUAD. Additionally, nicotine metabolism and ECM remodeling were found to be associated with both LUSC and LUAD, regardless of subtype, emphasizing the role of smoking in the development of lung cancer and ECM in the high aggressiveness and mortality of lung cancer.

Talniflumate abrogates mucin immune suppressive barrier improving efficacy of gemcitabine and nab-paclitaxel treatment in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease. This is due to its aggressive course, late diagnosis and its intrinsic drugs resistance. The complexity of the tumor, in terms of cell components and heterogeneity, has led to the approval of few therapies with limited efficacy. The study of the early stages of carcinogenesis provides the opportunity for the identification of actionable pathways that underpin therapeutic resistance.

METHODS

We analyzed 43 Intraductal papillary mucinous neoplasms (IPMN) (12 Low-grade and 31 High-grade) by Spatial Transcriptomics. Mouse and human pancreatic cancer organoids and T cells interaction platforms were established to test the role of mucins expression on T cells activity. Syngeneic mouse model of PDAC was used to explore the impact of mucins downregulation on standard therapy efficacy.

RESULTS

Spatial transcriptomics showed that mucin O-glycosylation pathway is increased in the progression from low-grade to high-grade IPMN. We identified GCNT3, a master regulator of mucins expression, as an actionable target of this pathway by talniflumate. We showed that talniflumate impaired mucins expression increasing T cell activation and recognition using both mouse and human organoid interaction platforms. In vivo experiments showed that talniflumate was able to increase the efficacy of the chemotherapy by boosting immune infiltration.

CONCLUSIONS

Finally, we demonstrated that combination of talniflumate, an anti-inflammatory drug, with chemotherapy effectively improves anti-tumor effect in PDAC.

Mucin Glycans: A Target for Cancer Therapy

Mucin glycans are an important component of the mucus barrier and a vital defence against physical and chemical damage as well as pathogens. There are 20 mucins in the human body, which can be classified into secreted mucins and transmembrane mucins according to their distributions. The major difference between them is that secreted mucins do not have transmembrane structural domains, and the expression of each mucin is organ and cell-specific. Under physiological conditions, mucin glycans are involved in the composition of the mucus barrier and thus protect the body from infection and injury. However, abnormal expression of mucin glycans can lead to the occurrence of diseases, especially cancer, through various mechanisms. Therefore, targeting mucin glycans for the diagnosis and treatment of cancer has always been a promising research direction. Here, we first summarize the main types of glycosylation (O-GalNAc glycosylation and N-glycosylation) on mucins and the mechanisms by which abnormal mucin glycans occur. Next, how abnormal mucin glycans contribute to cancer development is described. Finally, we summarize MUC1-based antibodies, vaccines, radio-pharmaceuticals, and CAR-T therapies using the best characterized MUC1 as an example. In this section, we specifically elaborate on the recent new cancer therapy CAR-M, which may bring new hope to cancer patients.

Sequencing Analysis of MUC6 and MUC16 Gene Fragments in Patients with Oropharyngeal Squamous Cell Carcinoma Reveals Novel Mutations: A Preliminary Study

The growing incidence of oropharyngeal squamous cell carcinoma (OPSCC) calls for better understanding of the mutational landscape of such cases. Mucins (MUCs) are multifunctional glycoproteins expressed by the epithelial cells and may be associated with the epithelial tumour invasion and progression. The present study aimed at the analysis of the sequence of selected MUC6 and MUC16 gene fragments in the tumour, as well as the margin, samples obtained from 18 OPSCC patients. Possible associations between the detected mutations and the clinicopathological and demographic characteristics of the study group were analysed. Sanger sequencing and bioinformatic data analysis of the selected MUC6 and MUC16 cDNA fragments were performed. Our study found 13 and 3 mutations in MUC6 and MUC16, respectively. In particular, one novelty variant found that the MUC6 gene (chr11:1018257 A>T) was the most frequent across our cohort, in both the tumour and the margin samples, and was then classified as a high impact, stop-gain mutation. The current study found novel mutations in MUC6 and MUC16 providing new insight into the genetic alternation in mucin genes among the OPSCC patients. Further studies, including larger cohorts, are recommended to recognise the pattern in which the mutations affect oropharyngeal carcinogenesis.

Modeling mucus physiology and pathophysiology in human organs-on-chips

The surfaces of human internal organs are lined by a mucus layer that ensures symbiotic relationships with commensal microbiome while protecting against potentially injurious environmental chemicals, toxins, and pathogens, and disruption of this layer can contribute to disease development. Studying mucus biology has been challenging due to the lack of physiologically relevant human in vitro models. Here we review recent progress that has been made in the development of human organ-on-a-chip microfluidic culture models that reconstitute epithelial tissue barriers and physiologically relevant mucus layers with a focus on lung, colon, small intestine, cervix and vagina. These organ-on-a-chip models that incorporate dynamic fluid flow, air-liquid interfaces, and physiologically relevant mechanical cues can be used to study mucus composition, mechanics, and structure, as well as investigate its contributions to human health and disease with a level of biomimicry not possible in the past.

Chimeric Antigen Receptor T-Cell Therapy in Paediatric B-Cell Precursor Acute Lymphoblastic Leukaemia: Curative Treatment Option or Bridge to Transplant?

Chimeric antigen receptor T-cell therapy (CAR-T) targeting CD19 has been associated with remarkable responses in paediatric patients and adolescents and young adults (AYA) with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). Tisagenlecleucel, the first approved CD19 CAR-T, has become a viable treatment option for paediatric patients and AYAs with BCP-ALL relapsing repeatedly or after haematopoietic stem cell transplantation (HSCT). Based on the chimeric antigen receptor molecular design and the presence of a 4-1BB costimulatory domain, tisagenlecleucel can persist for a long time and thereby provide sustained leukaemia control. "Real-world" experience with tisagenlecleucel confirms the safety and efficacy profile observed in the pivotal registration trial. Recent guidelines for the recognition, management and prevention of the two most common adverse events related to CAR-T - cytokine release syndrome and immune-cell-associated neurotoxicity syndrome - have helped to further decrease treatment toxicity. Consequently, the questions of how and for whom CD19 CAR-T could substitute HSCT in BCP-ALL are inevitable. Currently, 40-50% of R/R BCP-ALL patients relapse post CD19 CAR-T with either CD19- or CD19+ disease, and consolidative HSCT has been proposed to avoid disease recurrence. Contrarily, CD19 CAR-T is currently being investigated in the upfront treatment of high-risk BCP-ALL with an aim to avoid allogeneic HSCT and associated treatment-related morbidity, mortality and late effects. To improve survival and decrease long-term side effects in children with BCP-ALL, it is important to define parameters predicting the success or failure of CAR-T, allowing the careful selection of candidates in need of HSCT consolidation. In this review, we describe the current clinical evidence on CAR-T in BCP-ALL and discuss factors associated with response to or failure of this therapy: product specifications, patient- and disease-related factors and the impact of additional therapies given before (e.g., blinatumomab and inotuzumab ozogamicin) or after infusion (e.g., CAR-T re-infusion and/or checkpoint inhibition). We discuss where to position CAR-T in the treatment of BCP-ALL and present considerations for the design of supportive trials for the different phases of disease. Finally, we elaborate on clinical settings in which CAR-T might indeed replace HSCT.

Mucin 5AC Serves as the Nexus for β-Catenin/c-Myc Interplay to Promote Glutamine Dependency During Pancreatic Cancer Chemoresistance

BACKGROUND & AIMS

A major clinical challenge for patients with pancreatic cancer (PC) is metabolic adaptation. Neoplastic cells harboring molecular perturbations suffice for their increased anabolic demand and nucleotide biosynthesis to acquire chemoresistance. The mucin 5AC expressed de novo in malignant pancreas promotes cancer cell stemness and is significantly associated with poor patient survival. Identification of MUC5AC-associated drivers of chemoresistance through metabolic alterations may facilitate the sculpting of a new combinatorial regimen.

METHODS

The contributions of MUC5AC to glutaminolysis and gemcitabine resistance were examined by The Cancer Genome Atlas data analysis, RNA sequencing, and immunohistochemistry analysis on pancreatic tissues of KrasG12D;Pdx1-Cre (KC) and KrasG12D;Pdx1-Cre;Muc5ac-/- mice. These were followed by metabolite flux assays as well as biochemical and xenograft studies on MUC5AC-depleted human and murine PC cells. Murine and human pancreatic 3-dimensional tumoroids were used to evaluate the efficacy of gemcitabine in combination with β-catenin and glutaminolysis inhibitors.

RESULTS

Transcriptional analysis showed that high MUC5AC-expressing human and autochthonous murine PC tumors exhibit higher resistance to gemcitabine because of enhanced glutamine use and nucleotide biosynthesis. Gemcitabine treatment led to MUC5AC overexpression, resulting in disruption of E-cadherin/β-catenin junctions and the nuclear translocation of β-catenin, which increased c-Myc expression, with a concomitant rise in glutamine uptake and glutamate release. MUC5AC depletion and glutamine deprivation sensitized human PC cells to gemcitabine, which was obviated by glutamine replenishment in MUC5AC-expressing cells. Coadministration of β-catenin and glutaminolysis inhibitors with gemcitabine abrogated the MUC5AC-mediated resistance in murine and human tumoroids.

CONCLUSIONS

The MUC5AC/β-catenin/c-Myc axis increases the uptake and use of glutamine in PC cells, and cotargeting this axis along with gemcitabine may improve therapeutic efficacy in PC.

Molecular docking investigation of calotropone as a potential natural therapeutic agent against pancreatic cancer

A natural bioactive compound named calotropone has been reported as a drug candidate for several cancers, including pancreatic cancers. Herein, we used molecular docking approach to test the possible mechanisms of action of calotropone in inhibiting the growth of pancreatic cell cancer with gemcitabine as the positive control. By employing AutoDock Vina, we studied the molecular interaction between calotropone and pancreatic cancer-associated proteins, namely Glucosaminyl (N-Acetyl) Transferase 3, Glutamic-Oxaloacetic Transaminase 1, Tyrosine-protein kinase Met (c-Met), peroxisome proliferator-activated receptor γ, Budding Uninhibited by Benzimidazole 1, A Disintegrin and Metalloproteinase 10, Sex-determining region Y and Nuclear Factor kappa Beta (Nf-Kβ). Higher affinity energies of calotropone toward the aforementioned proteins (ranging from ‒7.3 to ‒9.3 kcal/mol) indicate that calotropone may work in the same manner as anticancer drug gemcitabine. Highest docking score was found at the interaction of calotropone and Nf-Kβ (‒9.3 kcal/mol).

Mucinous adenocarcinoma: A unique clinicopathological subtype in colorectal cancer

Mucinous adenocarcinoma (MAC) is a unique clinicopathological subtype of colorectal cancer, which is characterized by extracellular mucinous components that comprise at least 50% of the tumor tissue. The clinical characteristics, molecular features, response to chemo-/radiotherapy, and prognosis of MAC are different from that of non-MAC (NMAC). MAC is more common in the proximal colon, with larger volume, higher T-stage, a higher proportion of positive lymph nodes, poorer tumor differentiation, and a higher proportion of peritoneal implants compared to NMAC. Although biopsy is the main diagnostic method for MAC, magnetic resonance imaging is superior in accuracy, especially for rectal carcinoma. The aberrant expression of mucins, including MUC1, MUC2 and MUC5AC, is a notable feature of MAC, which may be related to tumor invasion, metastasis, inhibition of apoptosis, and chemo-/radiotherapy resistance. The genetic origin of MAC is mainly related to BRAF mutation, microsatellite instability, and the CpG island methylator phenotype pathway. In addition, the poor prognosis of rectal MAC has been confirmed by various studies, and that of colonic MAC is still controversial. In this review, we summarize the epidemiology, clinicopathological characteristics, molecular features, methods of diagnosis, and treatments of MAC in order to provide references for further fundamental and clinical research.

The mucin protein MUCL1 regulates melanogenesis and melanoma genes in a manner dependent on threonine content

Background

The regulation of melanogenesis has been investigated as a long‐held aim for pharmaceutical manipulations with denotations for malignancy of melanoma. Mucins have a protective function in epithelial organs; however, in the most outer organ, the skin, the role of mucins has not been studied enough.

Objectives

Our initial hypothesis developed from the identification of correlations between pigmentation and expressions of skin mucins, particularly those existing in skin tissue. We aimed to investigate the action of mucins in human melanocytic cells.

Materials and methods

The expression of mucin proteins in human skin was investigated using microarray data from the Human Protein Atlas consortium (HPA) and the Genotype‐Tissue Expression consortium (GTEx) database. Mucin expression was measured at RNA and protein levels in melanoma cells. The findings were further validated and confirmed by analysis of independent experiments.

Results

We found that the several mucin proteins showed expression in human skin cells and among these, mucin‐like protein 1 (MUCL1) showed the highest expression and also clear negative correlation with melanogenesis in epidermal melanocytes. We confirmed the correlations between melanogenesis and MUCL1 by revealing negative correlations in melanocytes with different melanin production, resulting from increased composition of threonine, mucin‐conforming amino acid, and increased autophagy‐related forkhead‐box O signalling. Furthermore, threonine itself affects melanogenesis and metastatic activity in melanoma cells.

Conclusions

We identified a significant association between MUCL1 and threonine with melanogenesis and metastasis‐related genes in melanoma cells. Our results define a novel mechanism of mucin regulation, suggesting diagnostic and preventive roles of MUCL1 in cutaneous melanoma.

Whatis already known about this topic?

Despite considerable advances in radioactive therapeutics or chemotherapeutic approaches for the treatment of abnormal melanogenesis, there are still many caveats to delivery, effectiveness and safety, thus leaving a necessity for more immediate pharmaceutical targets.

Mucins have protective and chemical barrier functions in epithelial organs; however, in the skin, mucin has scarce expression and is known only as a diagnostic aid in skin disorders such as mucinosis.

Whatdoes this study add?

We provide detailed analysis demonstrating the potential of mucin‐like protein 1 (MUCL1), which showed negative correlations in melanocytes with different melanin production, resulting from increased composition of threonine and increased autophagy‐related forkhead‐box O signalling in epidermal melanocytes and melanoma cells.

We established that through an alternative pathway for MUCL1 biosynthesis, threonine supplementation recovers MUCL1 levels in melanoma. Changes, brought on by the essential amino acid threonine, resulted in substantial modulations in melanogenesis and reduced metastasis‐related genes.

Whatis the translational message?

This study demonstrates for the first time that the mucin protein of skin cells is compounded by distorted mucin homeostasis, with major effects on melanogenesis and metastasis‐related genes in melanoma.

We anticipate that these novel findings will be of keen interest to the community of scientists and medical practitioners examining skin dysfunction.

Linked Comment: C. Casalou and D.J. Tobin. Br J Dermatol 2022; 186:388–389.

Plain language summary available online

Changes of Gastric Juice Microenvironment in Patients with Fundic Gland Polyp and Hyperplastic Polyp

INTRODUCTION

The aim of this study was to study the relationship between the formation of gastric fundic gland polyp and gastric hyperplastic polyp (HP) and the changes of gastric juice microenvironment.

METHODS

The proton-pump inhibitor (PPI) applications to patients were recorded. Gastric juices and biopsy polyps were collected for pathological examination, H. pylori tests, biomarkers, and MUC1, MUC2, MUC5AC expression measurement.

RESULTS

Among 34,892 patients, the detection rate of gastric fundic gland polyps was significantly higher than that of gastric HPs (p < 0.01). The incidence rate of gastric fundic gland polyp and gastric HP in PPI users (n = 3,886) was higher than that of non-PPI users (p < 0.01). The occurrence of polyp was positively related to the duration of PPI application and the H. pylori-positive rate. The bile reflux rate between fundic gland polys group (17.61%) and HPs (28.67%) was significantly different (p < 0.01). The levels of gastric juice Gastrin-17, epidermal growth factor (EGF) and MUC2 from patients with gastric fundic gland polyps and gastric HPs were higher than those in the control group (p < 0.01). However, patients with gastric fundic gland polyps and HPs had significantly lower gastric juice PGE2 and MUC5AC (p < 0.01).

CONCLUSION

PPI application, H. pylori infection, and bile reflux are the potential risk factors for formation of fundic gland polyps and HPs. The potential mechanism of polyps' formation can be related to the levels of Gastrin-17, EGF, MUC2, PGE2, and MUC5AC in gastric juice.

Molecular docking of two cytotoxic compounds from Calotropis gigantea leaves against therapeutic molecular target of pancreatic cancer

The utilization of natural compounds as therapeutic agents to treat pancreatic cancer has recently focused on natural drug research. Calotropis gigantea has long been believed to be a medicinal plant that helps in treating various diseases. The bioactive compounds 9-metoxipinoresinol and isoliquiritigenin isolated from C. gigantea leaves are proven to act as therapeutic agents by inhibiting the cancer cell growth of Panc-1 cells. This study aimed to screen the potential molecular inhibition mechanisms of 9-metoxipinoresinol and isoliquiritigenin against pancreatic cancer development in-silico. We analyzed the activity of the aforementioned two compounds as inhibitors of several proteins that play a role in the growth of pancreatic cancer cells, such as GCNT3, GOT1, c-Met, PPARγ, BUB1, and NF-κβ, through molecular docking investigation. Our data suggested that 9-metoxipinoresinol and isoliquiritigenin were able to have well interaction with the target proteins, in which the predicted affinity energy ranged between -6.8 and 8.7 kcal/mol. The docking scores of 9-metoxipinoresinol and isoliquiritigenin were higher than the standard drug used (gemcitabine). Based on the binding affinity energy, GCNT3 and BUB1 are potentially to be used as target molecules for cancer therapy using 9-metoxipinoresinol and isoliquiritigenin, respectively.

CTSE Overexpression Is an Adverse Prognostic Factor for Survival among Rectal Cancer Patients Receiving CCRT

The introduction of preoperative concurrent chemoradiotherapy (CCRT) increases the rate of anal preservation and allows tumor downstaging for clinical stage T3/T4 or node-positive rectal cancer patients. However, there is no precise predictive tool to verify the presence of residual tumor apart from surgical resection. The gastrointestinal (GI) tract not only digests nutrients but also coordinates immune responses. As the outermost layer of the GI tract, mucus plays a key role in mediating the interaction between the digestive and immune systems, and aberrant mucus mesh formation may cause chemoresistance by impeding drug delivery. However, the correlations among digestion-related genes, mucin synthesis, and chemoresistance remain poorly understood. In the present study, we evaluated genes related to digestion (GO: 0007586) and identified cathepsin E (CTSE), which is involved in immune regulation, as the most significantly upregulated gene associated with CCRT resistance in rectal cancer in a public transcriptome dataset (GSE35452). We recovered 172 records of rectal cancer patients receiving CCRT followed by surgical resection from our biobank and evaluated the expression level of CTSE using immunohistochemistry. The results revealed that tumors with CTSE overexpression were significantly correlated with pre-CCRT and post-CCRT positive nodal status (both p < 0.001), advanced pre-CCRT and post-CCRT tumor status (p < 0.001 and p = 0.002), perineural invasion (p = 0.023), vascular invasion (p < 0.001), and a lesser degree of tumor regression (p = 0.003). At the univariate level, CTSE overexpression was an adverse prognostic factor for all three endpoints: disease-specific survival (DSS), metastasis-free survival (MeFS) (both p < 0.0001), and local recurrence-free survival (LRFS) (p = 0.0001). At the multivariate level, CTSE overexpression remained an independent prognostic factor for poor DSS, MeFS (both p = 0.005), and LRFS (p = 0.019). Through bioinformatics analysis, we speculated that CTSE overexpression may confer CCRT resistance by forming a defensive mucous barrier. Taken together, these results suggest that CTSE overexpression is related to CCRT resistance and inferior survival in rectal cancer patients, highlighting the potential predictive and prognostic value of CTSE expression.

Plasma Exosomal miRNA Levels after Radiotherapy Are Associated with Early Progression and Metastasis of Cervical Cancer: A Pilot Study

Plasma exosomal miRNAs are key regulators of cell-cell interactions associated with several biological functions in patients with cancer. This pilot study aimed to investigate the log₂ fold change (log₂FC) of the expression of exosomal miRNAs and related mRNAs in the blood of patients with cervical cancer to identify prognostic markers better than those currently available. We sequenced plasma exosomal RNA from 56 blood samples collected from 28 patients with cervical cancer, who had been treated with concurrent chemoradiotherapy (CCRT). Changes in the expression of miRNAs and mRNAs before and after CCRT were represented as log₂FC. Their biological functions were studied by miRNA-mRNA network analysis, using ingenuity pathway analysis, after the selection of two groups of miRNAs, each associated with early progression (EP) and metastasis, also described as initial stage. Seven patients experienced EP, three of whom died within four months after progression. Reduced levels of miR-1228-5p, miR-33a-5p, miR-3200-3p, and miR-6815-5p and increased levels of miR-146a-3p in patients with EP revealed unresolved inflammation, with accompanying increased expression of PCK1 and decreased expression of FCGR1A. Increased levels of miR-605-5p, miR-6791-5p, miR-6780a-5p, and miR-6826-5p and decreased levels of miR-16-1-3p (or 15a-3p) were associated with the degree of metastasis and led to the systemic activation of myeloid, endothelial, and epithelial cells, as well as neurons, phagocytes, and platelets. Log₂FCs in the expression of miRNAs and mRNAs from plasma exosomes after CCRT are associated with EP and metastasis, reflecting unresolved inflammation and systemic microenvironmental factors, respectively. However, this study, supported by preliminary data insufficient to reach clear conclusions, should be verified in larger prospective cohorts.

ST6GalNAc-I promotes lung cancer metastasis by altering MUC5AC sialylation

Lung cancer (LC) is the leading cause of cancer-related mortality. However, the molecular mechanisms associated with the development of metastasis are poorly understood. Understanding the biology of LC metastasis is critical to unveil the molecular mechanisms for designing targeted therapies. We developed two genetically engineered LC mouse models Kras^G12D/+ ; Trp53^R172H/+ ; Ad-Cre (KPA) and Kras^G12D/+ ; Ad-Cre (KA). Survival analysis showed significantly (P = 0.0049) shorter survival in KPA tumor-bearing mice as compared to KA, suggesting the aggressiveness of the model. Our transcriptomic data showed high expression of N-acetylgalactosaminide alpha-2, 6-sialyltransferase 1 (St6galnac-I) in KPA compared to KA tumors. ST6GalNAc-I is an O-glycosyltransferase, which catalyzes the addition of sialic acid to the initiating GalNAc residues forming sialyl Tn (STn) on glycoproteins, such as mucins. Ectopic expression of species-specific p53 mutants in the syngeneic mouse and human LC cells led to increased cell migration and high expression of ST6GalNAc-I, STn, and MUC5AC. Immunoprecipitation of MUC5AC in the ectopically expressing p53^R175H cells exhibited higher affinity toward STn. In addition, ST6GalNAc-I knockout (KO) cells also showed decreased migration, possibly due to reduced glycosylation of MUC5AC as observed by low STn on the glycoprotein. Interestingly, ST6GalNAc-I KO cells injected mice developed less liver metastasis (P = 0.01) compared to controls, while colocalization of MUC5AC and STn was observed in the liver metastatic tissues of control mice. Collectively, our findings support the hypothesis that mutant p53^R175H mediates ST6GalNAc-I expression, leading to the sialyation of MUC5AC, and thus contribute to LC liver metastasis.

MUC15 loss facilitates epithelial-mesenchymal transition and cancer stemness for prostate cancer metastasis through GSK3β/β-catenin signaling

Patients with prostate cancer (PCa) have a high incidence of relapse and metastasis. Unfortunately, the molecular mechanisms underlying these processes have not been fully elucidated. In our study, we demonstrate that MUC15, a member of the mucin family, is a novel tumor suppressor in PCa that modulates epithelial-mesenchymal transition (EMT) and cancer stemness, contributing to PCa metastasis. First, MUC15 expression was found to be decreased in PCa tissues compared with para-carcinoma tissues. Moreover, we observed that MUC15 suppressed cell migration and invasion, both in vitro and in vivo, but had no effect on cell proliferation. Mechanistically, knockdown of MUC15 increased GSK3β phosphorylation and promoted β-catenin nuclear translocation. Therefore, the β-catenin-specific inhibitors XAV939 and PRI-724 rescued EMT in MUC15-deficient cell lines. Taken together, these results indicate that MUC15 is downregulated in PCa tissues and serves as a potential target to prevent PCa metastasis, which can inhibit EMT and cancer stemness via the GSK3β/β-catenin signaling pathway.

Mucins reprogram stemness, metabolism and promote chemoresistance during cancer progression

Mucins are high-molecular-weight glycoproteins dysregulated in aggressive cancers. The role of mucins in disease progression, tumor proliferation, and chemotherapy resistance has been studied extensively. This article provides a comprehensive review of mucin's function as a physical barrier and the implication of mucin overexpression in impeded drug delivery to solid tumors. Mucins regulate the epithelial to mesenchymal transition (EMT) of cancer cells via several canonical and non-canonical oncogenic signaling pathways. Furthermore, mucins play an extensive role in enriching and maintaining the cancer stem cell (CSC) population, thereby sustaining the self-renewing and chemoresistant cellular pool in the bulk tumor. It has recently been demonstrated that mucins regulate the metabolic reprogramming during oncogenesis and cancer progression, which account for tumor cell survival, proliferation, and drug-resistance. This review article focuses on delineating mucin's role in oncogenic signaling and aberrant regulation of gene expressions, culminating in CSC maintenance, metabolic rewiring, and development of chemoresistance, tumor progression, and metastasis.

Meta-analysis of global and high throughput public gene array data for robust vascular gene expression discovery in chronic rhinosinusitis: Implications in controlled release

BACKGROUND

Chronic inflammation is known to cause alterations in vascular homeostasis that directly affects blood vessel morphogenesis, angiogenesis, and tissue permeability. These phenomena have been investigated and exploited for targeted drug delivery applications in the context of cancers and other disease processes. Vascular pathophysiology and its associated genes and signaling pathways, however, have not been systematically investigated in patients with chronic rhinosinusitis (CRS). Understanding the interplay between key vascular signaling pathways and top biomarkers associated with CRS may facilitate the development of new targeted delivery strategies and treatment paradigms. Herein, we report findings from a gene meta-analysis to identify key vascular pathways and top genes involved in CRS.

METHODS

Proprietary software (Illumina BaseSpace Correlation Engine) and open-access data sets were used to perform a gene meta-analysis to systematically determine significant differences between key vascular biomarkers and vascular signaling pathways expressed in sinonasal tissue biopsies of controls and patients with CRS.

RESULTS

Thirteen studies were initially identified, and then reduced to five after applying exclusion principle algorithms. Genes associated with vasculature development and blood vessel morphogenesis signaling pathways were identified to be overexpressed among the top 15 signaling pathways. Out of many significantly upregulated genes, the levels of pro angiogenic genes such as early growth response (EGR3), platelet endothelial cell adhesion molecule (PECAM1) and L-selectin (SELL) were particularly significant in patients with CRS compared to controls.

DISCUSSION

Key vascular biomarkers and signaling pathways were significantly overexpressed in patients with CRS compared to controls, suggesting a contribution of vascular dysfunction in CRS pathophysiology. Vascular dysregulation and permeability may afford opportunities to develop drug delivery systems to improve efficacy and reduce toxicity of CRS treatment.

MUC Glycoproteins: Potential Biomarkers and Molecular Targets for Cancer Therapy

MUC proteins have great significance as prognostic and diagnostic markers as well as a potential target for therapeutic interventions in most cancers of glandular epithelial origin. These are high molecular weight glycosylated proteins located in the epithelial lining of several tissues and ducts. Mucins belong to a heterogeneous group of large O-glycoproteins that can be either secreted or membrane-bound. Glycosylation, a post-translational modification affects the biophysical, functional and biochemical properties and provides structural complexity for these proteins. Aberrant expression and glycosylation of mucins contribute to tumour survival and proliferation in many cancers, which in turn activates numerous signalling pathways such as NF-kB, ERα, HIF, MAPK, p53, c-Src, Wnt and JAK-STAT, etc. This subsequently induces cancer cell growth, proliferation and metastasis. The present review mainly demonstrates the functional aspects of MUC glycoproteins along with its unique signalling mechanism and role of aberrant glycosylation in cancer progression and therapeutics. The importance of MUC proteins and its subtypes in a wide spectrum of cancers including but not limited to breast cancer, colorectal cancer, endometrial and cervical cancer, lung cancer, primary liver cancer, pancreatic cancer, prostate cancer and ovarian cancer has been exemplified with significance in targeting the same. Several patents associated with the MUC proteins in the field of cancer therapy are also emphasized in the current review.

Assembly Mechanism of Mucin and von Willebrand Factor Polymers

The respiratory and intestinal tracts are exposed to physical and biological hazards accompanying the intake of air and food. Likewise, the vasculature is threatened by inflammation and trauma. Mucin glycoproteins and the related von Willebrand factor guard the vulnerable cell layers in these diverse systems. Colon mucins additionally house and feed the gut microbiome. Here, we present an integrated structural analysis of the intestinal mucin MUC2. Our findings reveal the shared mechanism by which complex macromolecules responsible for blood clotting, mucociliary clearance, and the intestinal mucosal barrier form protective polymers and hydrogels. Specifically, cryo-electron microscopy and crystal structures show how disulfide-rich bridges and pH-tunable interfaces control successive assembly steps in the endoplasmic reticulum and Golgi apparatus. Remarkably, a densely O-glycosylated mucin domain performs an organizational role in MUC2. The mucin assembly mechanism and its adaptation for hemostasis provide the foundation for rational manipulation of barrier function and coagulation.

Mucins in Intestinal Mucosal Defense and Inflammation: Learning From Clinical and Experimental Studies

Throughout the gastrointestinal (GI) tract, a distinct mucus layer composed of highly glycosylated proteins called mucins plays an essential role in providing lubrication for the passage of food, participating in cell signaling pathways and protecting the host epithelium from commensal microorganisms and invading pathogens, as well as toxins and other environmental irritants. These mucins can be broadly classified into either secreted gel-forming mucins, those that provide the structural backbone for the mucus barrier, or transmembrane mucins, those that form the glycocalyx layer covering the underlying epithelial cells. Goblet cells dispersed among the intestinal epithelial cells are chiefly responsible for the synthesis and secretion of mucins within the gut and are heavily influenced by interactions with the immune system. Evidence from both clinical and animal studies have indicated that several GI conditions, including inflammatory bowel disease (IBD), colorectal cancer, and numerous enteric infections are accompanied by considerable changes in mucin quality and quantity. These changes include, but are not limited to, impaired goblet cell function, synthesis dysregulation, and altered post-translational modifications. The current review aims to highlight the structural and functional features as well as the production and immunological regulation of mucins and the impact these key elements have within the context of barrier function and host defense in intestinal inflammation.

Immunohistochemical scoring of CD38 in the tumor microenvironment predicts responsiveness to anti-PD-1/PD-L1 immunotherapy in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-associated mortality globally. Immune-checkpoint blockade (ICB) is one of the systemic therapy options for HCC. However, response rates remain low, necessitating robust predictive biomarkers. In the present study, we examined the expression of CD38, a molecule involved in the immunosuppressive adenosinergic pathway, on immune cells present in the tumor microenvironment. We then investigated the association between CD38 and ICB treatment outcomes in advanced HCC.

Methods

Clinically annotated samples from 49 patients with advanced HCC treated with ICB were analyzed for CD38 expression using immunohistochemistry (IHC), multiplex immunohistochemistry/immunofluorescence (mIHC/IF) and multiplex cytokine analysis.

Results

IHC and mIHC/IF analyses revealed that higher intratumoral CD38⁺ cell proportion was strongly associated with improved response to ICB. The overall response rates to ICB was significantly higher among patients with high proportion of total CD38⁺cells compared with patients with low proportion (43.5% vs 3.9%, p=0.019). Higher responses seen among patients with a high intratumoral CD38⁺cell proportion translated to a longer median progression-free survival (mPFS, 8.21 months vs 1.64 months, p=0.0065) and median overall survival (mOS, 19.06 months vs 9.59 months, p=0.0295). Patients with high CD38⁺CD68⁺macrophage density had a better mOS of 34.43 months compared with 9.66 months in patients with low CD38⁺CD68⁺ macrophage density. CD38^hi macrophages produce more interferon γ (IFN-γ) and related cytokines, which may explain its predictive value when treated with ICB.

Conclusions

A high proportion of CD38⁺ cells, determined by IHC, predicts response to ICB and is associated with superior mPFS and OS in advanced HCC.

Overexpression of MUC16 predicts favourable prognosis in MUC16-mutant cervical cancer related to immune response

Cervical cancer (CC) is the fourth ranking gynaecologic tumour in women worldwide, with respect to both incidence and mortality. MUC16 is one of the most frequently mutated genes, which functions as a tumour marker in CC. In the present study, mutation, clinical and RNA-Seq data collected from The Cancer Genome Atlas database were used to investigate the association between MUC16 mutation, immune response and clinical prognosis in CC. mRNA expression levels from the TCGA datasets and the results from the present study demonstrated that MUC16 was overexpressed in CC samples; however, there was no difference between mutant and wild-type CC samples. Furthermore, the results indicated that patients with MUC16-mutant overexpression had a prolonged survival time. In addition, overexpression of MUC16 was associated with immune responses in the microenvironment of MUC16-mutant CC. Immune responses were upregulated in patients with early-stage MUC16-mutant. The results from the present study provided novel biomarkers for potential immunotherapy approaches for CC.

NIR-dye based mucoadhesive nanosystem for photothermal therapy in breast cancer cells

Breast cancer is one of the leading causes of mortality in women, worldwide. The average survival rate of patients suffering from advanced breast cancer is about 27% for five years. Photothermal therapy employing biodegradable nanoparticle are extensively researched for enhanced anticancer therapy in breast cancer treatment. In the current study, we report a chitosan based mucoadherant and biodegradable niosome nanoparticle entrapping near infrared (NIR) dye (IR 806) for the treatment of breast cancer. Niosome entrapping IR 806 (NioIR) showed encapsulation efficacy of about 56 ± 2%. The prepared nanoparticles (NioIR) were further coated with chitosan (NioIR-C) to impart mucoadhesive property to the nanosystem. NioIR-C showed minimal degradation following NIR laser irradiation, thus enhancing its photothermal stability. They also exhibited efficient photothermal transduction, when compared with IR 806 dye. NioIR-C were biocompatible when treated with normal cell lines (NIH 3T3 and L929) and showed cytotoxicity towards breast cancer cell lines (MCF-7 and MDA-MB 231). When triggered with NIR laser, NioIR-C showed photothermal cell death (approximately 93%). The presence of chitosan coating on NioIR led to mucoadherence potential that further enhances the therapeutic effect on breast cancer cells when compared with IR 806 dye and NioIR. Thus NioIR-C can be a promising nanosystem for effective treatment of breast cancer using photothermal therapy.

Development of human ectocervical tissue models with physiologic endocrine and paracrine signaling†

There is a shortage of research models that adequately represent the unique mucosal environment of human ectocervix, limiting development of new therapies for treating infertility, infection, or cancer. We developed three microphysiologic human ectocervix models to study hormone action during homeostasis. First, we reconstructed ectocervix using decellularized extracellular matrix scaffolds, which supported cell integration and could be clinically useful. Secondly, we generated organotypic systems consisting of ectocervical explants co-cultured with murine ovaries or cycling exogenous hormones, which mimicked human menstrual cycles. Finally, we engineered ectocervix tissue consisting of tissue-specific stromal-equivalents and fully-differentiated epithelium that mimicked in vivo physiology, including squamous maturation, hormone response, and mucin production, and remained viable for 28 days in vitro. The localization of differentiation-dependent mucins in native and engineered tissue was identified for the first time, which will allow increased efficiency in mucin targeting for drug delivery. In summary, we developed and characterized three microphysiologic human ectocervical tissue models that will be useful for a variety of research applications, including preventative and therapeutic treatments, drug and toxicology studies, and fundamental research on hormone action in a historically understudied tissue that is critical for women's health.

Development of a Computational Tool for Automated Interpretation of Intact O-Glycopeptide Tandem Mass Spectra from Single Proteins

Precise and automated analysis of site-specific O-glycosylation on single proteins is crucial for comprehensive characterization of some important glycoproteins, such as tumor biomarkers and recombinant drug proteins. Mass spectrometry has been proven to be a powerful technique for protein sequencing and N-glycosylation analysis. However, challenges remain in developing computational tools for intact O-glycopeptide analysis, which has greatly hindered the development of mass-spectrometry-based O-glycosylation analysis. Herein, an integrated strategy together with a dedicated automated computational tool termed AOGP was developed for intact O-glycopeptide analysis on single proteins. AOGP utilized de novo sequencing for O-glycans and a database search strategy for peptide backbones. The false discovery rate (FDR) of the identification results was controlled and validated by a mixed Gaussian distribution estimation method. AOGP exhibited superior performance in identifying intact O-glycopeptides of the human erythropoietin with a total of 188 O-glycopeptide spectra reported under 1% FDR. AOGP is developed in Python, is fully open-sourced, and is equipped with a user-friendly interface. Such an easy-operating and robust tool would greatly facilitate O-glycosylation analysis on single proteins in tumor biomarker and recombinant drug protein development.

Molecular implications of MUC5AC-CD44 axis in colorectal cancer progression and chemoresistance

BACKGROUND

Differential expression of mucins has been associated with several cancers including colorectal cancer (CRC). In normal physiological conditions, secretory mucin MUC5AC is not expressed in the colonic mucosa, whereas its aberrant expression is observed during development of colon cancer and its precursor lesions. To date, the molecular mechanism of MUC5AC in CRC progression and drug resistance remains obscure.

METHODS

MUC5AC expression was determined in colon tissue microarray by immunohistochemistry. A RNA interference and CRISPR/Cas9-mediated system was used to knockdown/knockout the MUC5AC in CRC cell lines to delineate its role in CRC tumorigenesis using in vitro functional assays and in vivo (sub-cutaneous and colon orthotopic) mouse models. Finally, CRC cell lines and xenograft models were used to identify the mechanism of action of MUC5AC.

RESULTS

Overexpression of MUC5AC is observed in CRC patient tissues and cell lines. MUC5AC expression resulted in enhanced cell invasion and migration, and decreased apoptosis of CRC cells. MUC5AC interacted with CD44 physically, which was accompanied by the activation of Src signaling. Further, the presence of MUC5AC resulted in enhanced tumorigenesis and appearance of metastatic lesions in orthotopic mouse model. Additionally, up-regulation of MUC5AC resulted in resistance to 5-fluorouracil (5-FU) and oxaliplatin, and its knockout increased sensitivity to these drugs. Finally, we observed that up-regulation of MUC5AC conferred resistance to 5-FU through down-regulation of p53 and its target gene p21 and up-regulation of β-catenin and its target genes CD44 and Lgr5.

CONCLUSION

Our findings suggest that differential expression of secretory mucin MUC5AC results in enhanced tumorigenesis and also confers chemoresistance via CD44/β-catenin/p53/p21 signaling.

The Immune Contexture Associates with the Genomic Landscape in Lung Adenomatous Premalignancy

Epithelial cells in the field of lung injury can give rise to distinct premalignant lesions that may bear unique genetic aberrations. A subset of these lesions may escape immune surveillance and progress to invasive cancer; however, the mutational landscape that may predict progression has not been determined. Knowledge of premalignant lesion composition and the associated microenvironment is critical for understanding tumorigenesis and the development of effective preventive and interception strategies. To identify somatic mutations and the extent of immune cell infiltration in adenomatous premalignancy and associated lung adenocarcinomas, we sequenced exomes from 41 lung cancer resection specimens, including 89 premalignant atypical adenomatous hyperplasia lesions, 15 adenocarcinomas in situ, and 55 invasive adenocarcinomas and their adjacent normal lung tissues. We defined nonsynonymous somatic mutations occurring in both premalignancy and the associated tumor as progression-associated mutations whose predicted neoantigens were highly correlated with infiltration of CD8⁺ and CD4⁺ T cells as well as upregulation of PD-L1 in premalignant lesions, suggesting the presence of an adaptive immune response to these neoantigens. Each patient had a unique repertoire of somatic mutations and associated neoantigens. Collectively, these results provide evidence for mutational heterogeneity, pathway dysregulation, and immune recognition in pulmonary premalignancy.Significance: These findings identify progression-associated somatic mutations, oncogenic pathways, and association between the mutational landscape and adaptive immune responses in adenomatous premalignancy.See related commentary by Merrick, p. 4811.

Advances in the relationship between glycosyltransferases and multidrug resistance in cancer

Despite great progress in clinical treatment, cancer remains a serious health problem contributing to significant morbidity and mortality worldwide. Although chemotherapy is a common therapeutic measure, multidrug resistance (MDR) presents a major challenge that often leads to poor prognosis. The abnormal expression of glycosyltransferases (GTs) leading to aberrant glycosylation patterns are considered a marker of cancer. Furthermore, the biosynthesis of these glycoconjugates has been associated with tumor proliferation, invasion and metastasis. Recently, studies have found that GTs are involved in mediating MDR in cancer cells through complex mechanisms and can influence therapeutic effect. In this review, we focus on several types of cancers and summarize previous studies on the correlation between GTs and MDR.

Catalytic asymmetric acetalization of carboxylic acids for access to chiral phthalidyl ester prodrugs

Carboxylic acids are common moieties in medicines. They can be converted to phthalidyl esters as prodrugs. Unfortunately, phthalidyl esters are now mostly prepared in racemic forms. This is not desirable because the two enantiomers of phthalidyl esters likely have different pharmacological effects. Here we address the synthetic challenges in enantioselective modification of carboxylic acids via asymmetric acetalizations. The key reaction step involves asymmetric addition of a carboxylic acid to the catalyst-bound intermediate. This addition step enantioselectively constructs a chiral acetal unit that lead to optically enriched phthalidyl esters. A broad range of carboxylic acids react effectively under mild and transition metal-free conditions. Preliminary bioactivity studies show that the two enantiomers of chlorambucil phthalidyl esters exhibit different anti-cancer activities to inhibit the growth of Hela cells. Our catalytic strategy of asymmetric acetalizations of carboxylic acids shall benefit future development of chiral phthalidyl ester prodrugs and related molecules.

Phthalidyl esters, commonly used prodrug moieties, are mostly prepared as a racemate. Here, the authors report an N-heterocylcic carbene-catalysed enantioselective acetalization of carboxylic acids and dialdehydes to give phthalidyl esters in high yields with good enantioselectivity.

Mucin 5B, carbonic anhydrase 9 and claudin 18 are potential theranostic markers of gallbladder carcinoma

AIMS

Gallbladder cancer (GBC) is an aggressive tumour that is usually diagnosed at advanced stages and is characterised by a poor prognosis. Using public data of normal human tissues, we found that mRNA and protein levels of mucin 5B (MUC5B) and carbonic anhydrase 9 (CA9) were highly increased in gallbladder tissues. In addition, previous evidence has shown that claudin 18 (CLDN18) protein expression is higher in GBC. The aim of this study was to perform an analysis of these cell surface proteins during the histological progression of GBC in order to identify their theranostic potential.

METHODS AND RESULTS

MUC5B expression, CA9 expression and CLDN18 expression were examined by immunohistochemistry in a series of 179 chronic cholecystitis (including 16 metaplastic tissues), 15 dysplasia and 217 GBC samples by the use of tissue microarray analysis. A composite staining score was calculated from staining intensity and percentage of positive cells. Immunohistochemical analysis showed high expression of MUC5B and CA9 among normal epithelium, metaplastic tissues, and dysplastic tissues. However, expression of both proteins was observed in roughly 50% of GBC samples. In contrast, CLDN18 was absent in normal epithelium, but its expression was higher in metaplastic cells. Among GBC cases, approximately half showed high CLDN18 expression. No associations were found between MUC5B, CA9 and CLDN18 expression and any clinicopathological features.

CONCLUSIONS

CLDN18 is a new metaplasia marker in gallbladder tissues, and is conserved in approximately half of GBC cases. MUC5B and CA9 are highly conserved during GBC histological progression. The three markers are potential theranostic markers, in particular CA9 and CLDN18, for which there are already targeted therapies available.

Targeting Groups Employed in Selective Dendrons and Dendrimers

The design of compounds with directed action to a defined organ or tissue is a very promising approach, since it can decrease considerably the toxicity of the drug/bioactive compound. For this reason, this kind of strategy has been greatly important in the scientific community. Dendrimers, on the other hand, comprise extremely organized macromolecules with many peripheral functionalities, stepwise controlled synthesis, and defined size. These nanocomposites present several biological applications, demonstrating their efficiency to act in the pharmaceutical field. Considering that, the main purpose of this review was describing the potential of dendrons and dendrimers as drug targeting, applying different targeting groups. This application has been demonstrated through interesting examples from the literature considering the last ten years of publications.

Every step of the way: integrins in cancer progression and metastasis

Cell adhesion to the extracellular matrix is fundamental to tissue integrity and human health. Integrins are the main cellular adhesion receptors that through multifaceted roles as signalling molecules, mechanotransducers and key components of the cell migration machinery are implicated in nearly every step of cancer progression from primary tumour development to metastasis. Altered integrin expression is frequently detected in tumours, where integrins have roles in supporting oncogenic growth factor receptor (GFR) signalling and GFR-dependent cancer cell migration and invasion. In addition, integrins determine colonization of metastatic sites and facilitate anchorage-independent survival of circulating tumour cells. Investigations describing integrin engagement with a growing number of versatile cell surface molecules, including channels, receptors and secreted proteins, continue to lead to the identification of novel tumour-promoting pathways. Integrin-mediated sensing, stiffening and remodelling of the tumour stroma are key steps in cancer progression supporting invasion, acquisition of cancer stem cell characteristics and drug resistance. Given the complexity of integrins and their adaptable and sometimes antagonistic roles in cancer cells and the tumour microenvironment, therapeutic targeting of these receptors has been a challenge. However, novel approaches to target integrins and antagonism of specific integrin subunits in stringently stratified patient cohorts are emerging as potential ways forward.

The Role of Tumor Microenvironment in Chemoresistance: To Survive, Keep Your Enemies Closer

Chemoresistance is a leading cause of morbidity and mortality in cancer and it continues to be a challenge in cancer treatment. Chemoresistance is influenced by genetic and epigenetic alterations which affect drug uptake, metabolism and export of drugs at the cellular levels. While most research has focused on tumor cell autonomous mechanisms of chemoresistance, the tumor microenvironment has emerged as a key player in the development of chemoresistance and in malignant progression, thereby influencing the development of novel therapies in clinical oncology. It is not surprising that the study of the tumor microenvironment is now considered to be as important as the study of tumor cells. Recent advances in technological and analytical methods, especially ‘omics’ technologies, has made it possible to identify specific targets in tumor cells and within the tumor microenvironment to eradicate cancer. Tumors need constant support from previously ‘unsupportive’ microenvironments. Novel therapeutic strategies that inhibit such microenvironmental support to tumor cells would reduce chemoresistance and tumor relapse. Such strategies can target stromal cells, proteins released by stromal cells and non-cellular components such as the extracellular matrix (ECM) within the tumor microenvironment. Novel in vitro tumor biology models that recapitulate the in vivo tumor microenvironment such as multicellular tumor spheroids, biomimetic scaffolds and tumor organoids are being developed and are increasing our understanding of cancer cell-microenvironment interactions. This review offers an analysis of recent developments on the role of the tumor microenvironment in the development of chemoresistance and the strategies to overcome microenvironment-mediated chemoresistance. We propose a systematic analysis of the relationship between tumor cells and their respective tumor microenvironments and our data show that, to survive, cancer cells interact closely with tumor microenvironment components such as mesenchymal stem cells and the extracellular matrix.