Emerging roles of MUC4 in cancer: a novel target for diagnosis and therapy

Molecular Responses of the Eukaryotic Cell Line INT407 on the Internalized Campylobacter jejuni-The Other Side of the Coin

Campylobacter jejuni is a zoonotic bacterium with the capacity to invade the epithelial cells during the pathogenic process. Several bacterial factors have been identified to contribute to this process, but our knowledge is still very limited about the response of the host. To reveal the major routes of this response, a whole-transcriptome analysis (WTA) was performed where gene expressions were compared between the 1st and the 3rd hours of internalization in INT407 epithelial cells. From the 41,769 human genes tested, altogether, 19,060 genes were shown through WTA to be influenced to different extents. The genes and regulation factors of transcription (296/1052; 28%), signal transduction (215/1052; 21%), apoptosis (153/1052; 15%), immune responses (97/1052; 9%), transmembrane transport (64/1052; 6%), cell-cell signaling (32/1052; 3%), cell-cell adhesions (29/1052; 3%), and carbohydrate metabolism (28/1052; 3%) were the most affected biological functions. A striking feature of the gene expression of this stage of the internalization process is the activation of both immune functions and apoptosis, which convincingly outlines that the invaded cell faces a choice between death and survival. The seemingly balanced status quo between the invader and the host is the result of a complex process that also affects genes known to be associated with postinfectious pathological conditions. The upregulation of TLR3 (3.79×) and CD36 (2.73×), two general tumor markers, and SERPINEB9 (11.37×), FNDC1 (7.58×), and TACR2 (8.84×), three factors of tumorigenesis, confirms the wider pathological significance of this bacterium.

Mucin 4 (MUC4) Protein is Expressed in B-Acute Lymphoblastic Leukemia (B-ALL) and is restricted to BCR::ABL1 Positive and BCR::ABL-like Subtypes

Mucin 4 (MUC4) is a transmembrane mucin that, like most mucins, is not expressed in normal hematopoietic cells but little is known about its expression in malignant hematopoiesis. B-Acute Lymphoblastic Leukemia (B-ALL) consists of genetically distinct disease subtypes with similarities and differences in gene expression most frequently studied at the mRNA level, which is less amenable to widespread routine clinical use. Here, we demonstrate using immunohistochemistry (IHC) that MUC4 protein is expressed in less than 10% of B-ALL with expression restricted to BCR::ABL1+ and BCR::ABL1-like (CRLF2 rearranged) subtypes of B-ALL (4/13, 31%). None (0/36, 0%) of the remaining B-ALL subtypes expressed MUC4. We compare clinical and pathologic features of MUC4+ and MUC4- BCR::ABL1+/like cases and most significantly report a possible shorter time to relapse for MUC4+ BCR::ABL1 B-ALL that would need to be validated in larger studies. In conclusion, MUC4 is a specific, albeit insensitive, marker for these high-risk subtypes of B-ALL. We propose that MUC4 IHC may be employed diagnostically to rapidly identify these B-ALL subtypes particularly in resource limited settings or when an aspirate sample is not available for ancillary genetic studies.

Pathological Implications of Mucin Signaling in Metastasis

The dynamic mucosal layer provides a selective protective barrier for the epithelial cells lining the body cavities. Diverse human malignancies exploit their intrinsic role to protect and repair epithelia for promoting growth and survival. Aberrant expression of mucin has been known to be associated with poor prognosis of many cancers. However, the emergence of new paradigms in the study of metastasis recognizes the involvement of MUC1, MUC4, MUC5AC, MUC5B, and MUC16 during metastasis initiation and progression. Hence mucins can be used as an attractive target in future diagnostic and therapeutic strategies. In this review, we discuss in detail about mucin family and its domains and the role of different mucins in regulating cancer progression and metastasis. In addition, we briefly discuss insights into mucins as a therapeutic agent.

Anti-mucin 4 fluorescent antibody brightly targets colon cancer in patient-derived orthotopic xenograft mouse models: A proof-of-concept study for future clinical applications

BACKGROUND

There is a high rate of positive surgical margins with resection of liver metastases in colorectal cancer (CRC). The present study reports using a fluorescent anti-mucin 4 (MUC4) antibodies to label primary CRC and liver metastases to better visualize tumor margins in mouse models.

METHODS

Western blotting for MUC4 protein expression of normal colon and CRC tumor lysates was performed. Orthotopic primary and liver metastatic CRC mouse models received anti-MUC4 antibody conjugated to IR800 (MUC4-IR800). Mice were sacrificed and imaged after 48 hours.

RESULTS

Western blotting demonstrated increased MUC4 expression in a human CRC cell line and patient-derived primary and liver-metastatic CRCs. The LS174T orthotopic primary CRC model tumor to background ratio (TBR) was 2.04 (±0.35). The patient-derived orthotopic xenograft (PDOX) primary CRC model TBR was 2.17 (±0.35). The PDOX liver metastasis model TBR was 1.56 (±0.53).

CONCLUSION

MUC4-IR800 provided bright labeling of primary and liver tumors in CRC orthotopic mouse models, demonstrating their future clinical potential for margin visualization in fluorescence guided surgery.

A framework for fibrolamellar carcinoma research and clinical trials

Fibrolamellar carcinoma (FLC), a rare, lethal hepatic cancer, occurs primarily in adolescents and young adults. Unlike hepatocellular carcinoma, FLC has no known association with viral, metabolic or chemical agents that cause cirrhosis. Currently, surgical resection is the only treatment demonstrated to achieve cure, and no standard of care exists for systemic therapy. Progress in FLC research illuminates a transition from an obscure cancer to one for which an interactive community seems poised to uncover fundamental mechanisms and initiate translation towards novel therapies. In this Roadmap, we review advances since the seminal discovery in 2014 that nearly all FLC tumours express a signature oncogene (DNAJB1-PRKACA) encoding a fusion protein (DNAJ-PKAc) in which the J-domain of a heat shock protein 40 (HSP40) co-chaperone replaces an amino-terminal segment of the catalytic subunit of the cyclic AMP-dependent protein kinase (PKA). Important gains include increased understanding of oncogenic pathways driven by DNAJ-PKAc; identification of potential therapeutic targets; development of research models; elucidation of immune mechanisms with potential for the development of immunotherapies; and completion of the first multicentre clinical trials of targeted therapy for FLC. In each of these key areas we propose a Roadmap for future progress.

Characterization of recombinant β subunit of human MUC4 mucin (rMUC4β)

MUC4 is a transmembrane mucin expressed on various epithelial surfaces, including respiratory and gastrointestinal tracts, and helps in their lubrication and protection. MUC4 is also aberrantly overexpressed in various epithelial malignancies and functionally contributes to cancer development and progression. MUC4 is putatively cleaved at the GDPH site into a mucin-like α-subunit and a membrane-tethered growth factor-like β-subunit. Due to the presence of several functional domains, the characterization of MUC4β is critical for understanding MUC4 biology. We developed a method to produce and purify multi-milligram amounts of recombinant MUC4β (rMUC4β). Purified rMUC4β was characterized by Far-UV CD and I-TASSER-based protein structure prediction analyses, and its ability to interact with cellular proteins was determined by the affinity pull-down assay. Two of the three EGF-like domains exhibited typical β-fold, while the third EGF-like domain and vWD domain were predominantly random coils. We observed that rMUC4β physically interacts with Ezrin and EGFR family members. Overall, this study describes an efficient and simple strategy for the purification of biologically-active rMUC4β that can serve as a valuable reagent for a variety of biochemical and functional studies to elucidate MUC4 function and generating domain-specific antibodies and vaccines for cancer immunotherapy.

Upgrade of an old drug: Auranofin in innovative cancer therapies to overcome drug resistance and to increase drug effectiveness

Auranofin is an oral gold(I) compound, initially developed for the treatment of rheumatoid arthritis. Currently, Auranofin is under investigation for oncological application within a drug repurposing plan due to the relevant antineoplastic activity observed both in vitro and in vivo tumor models. In this review, we analysed studies in which Auranofin was used as a single drug or in combination with other molecules to enhance their anticancer activity or to overcome chemoresistance. The analysis of different targets/pathways affected by this drug in different cancer types has allowed us to highlight several interesting targets and effects of Auranofin besides the already well-known inhibition of thioredoxin reductase. Among these targets, inhibitory-κB kinase, deubiquitinates, protein kinase C iota have been frequently suggested. To rationalize the effects of Auranofin by a system biology-like approach, we exploited transcriptomic data obtained from a wide range of cell models, extrapolating the data deposited in the Connectivity Maps website and we attempted to provide a general conclusion and discussed the major points that need further investigation.

Effects of Long-Term In Vitro Expansion on Genetic Stability and Tumor Formation Capacity of Stem Cells

Stem cell therapeutics are emerging as novel alternative treatments for various neurodegenerative diseases based on their regenerative potentials. However, stem cell transplantation might have side effects such as tumor formation that limit their clinical applications. Especially, in vitro expansion of stem cells might provoke genetic instability and tumorigenic potential. To address this issue, we analyzed genomic alterations of adult human multipotent neural cells (ahMNCs), a type of human adult neural stem cells, after a long-term in vitro culture process (passage 15) using sensitive analysis techniques including karyotyping, array comparative genomic hybridization (aCGH), and whole exome sequencing (WES). Although karyotyping did not find any major abnormalities in chromosomal number or structure, diverse copy number variations (CNVs) and genetic mutations were detected by aCGH and WES in all five independent ahMNCs. However, the number of CNVs and genetic mutations did not increase and many of them did not persist as in vitro culture progressed. Although most observed CNVs and genetic mutations were not shared by all five ahMNCs, nonsynonymous missense mutations at MUC4 were found in three out of five long-term cultured ahMNC lines. The genetic instability did not confer in vivo tumorigenic potential to ahMNCs. Collectively, these results indicate that, although genetic instability can be induced by long-term in vitro expansion of stem cells, it is not sufficient to fully exert tumor formation capacity of stem cells. Other functional effects of such genetic instability need to be further elucidated.

Pancreatic adenocarcinoma: A review of recent paradigms and advances in epidemiology, clinical diagnosis and management

Pancreatic cancer is one of the dreaded malignancies for both the patient and the clinician. The five-year survival rate of pancreatic adenocarcinoma (PDA) is as low as 2% despite multimodality treatment even in the best hands. As per the Global Cancer Observatory of the International Agency for Research in Cancer estimates of pancreatic cancer, by 2040, a 61.7% increase is expected in the total number of cases globally. With the widespread availability of next-generation sequencing, the entire genome of the tumors is being sequenced regularly, providing insight into their pathogenesis. As invasive PDA arises from pancreatic intraepithelial neoplasia and mucinous neoplasm and intraductal papillary neoplasm, screening for them can be beneficial as the disease is curable with resection at an early stage. Routine preoperative biliary drainage has no role in patients suffering from PDA with obstructive jaundice. If performed, metallic stents are preferred over plastic ones. Minimally invasive procedures are preferred to open procedures as they have less morbidity. The duct-to-mucosa technique for pancreaticojejunostomy is presently widely practiced. The role of intraperitoneal drains after surgery for PDA is controversial. Neoadjuvant chemoradiotherapy has been proven to have a significant role both in locally advanced as well as in resectable PDA. Many new regimens and drugs have been added in the arsenal of chemoradiotherapy for metastatic disease. The roles of immunotherapy and gene therapy in PDA are being investigated. This review article is intended to improve the understanding of the readers with respect to the latest updates of PDA, which may help to trigger new research ideas and make better management decisions.

MUC4 is expressed in alveolar rhabdomyosarcoma

AIMS

Mucin 4 (MUC4) is a transmembrane glycoprotein normally expressed by several human epithelial surfaces, including those of the colon, vagina, and respiratory tract. Although MUC4 overexpression is seen in various carcinomas, its expression among mesenchymal neoplasms is fairly specific to low-grade fibromyxoid sarcoma and sclerosing epithelioid fibrosarcoma. Having observed unanticipated anti-MUC4 immunoreactivity in rhabdomyosarcoma, we aimed to further characterise its expression.

METHODS AND RESULTS

Expression of MUC4 was assessed by immunohistochemistry in a total of 97 rhabdomyosarcomas using formalin-fixed paraffin-embedded tissue sections. MUC4 was expressed by 21 of 26 PAX3/7-FOXO1 fusion-positive cases, wherein immunoreactivity, varying from weak to strong, was present in 20-100% of neoplastic cells. With the exception of one sclerosing rhabdomyosarcoma showing immunoreactivity in 20% of cells, MUC4 was not expressed by embryonal (n = 28), sclerosing (n = 20), or pleomorphic (n = 23) rhabdomyosarcomas. Analysing published gene expression microarray data from a separate cohort of 33 fusion-positive and 25 fusion-negative rhabdomyosarcomas, we found on average a 11.4-fold increased expression in fusion-positive tumours (P = 0.0004).

CONCLUSIONS

MUC4 is expressed to a variable extent in the majority of PAX3/7-FOXO1 fusion-positive (alveolar) rhabdomyosarcomas, while expression in other rhabdomyosarcoma subtypes is rare.

Identification of Potential Driver Genes Based on Multi-Genomic Data in Cervical Cancer

Background: Cervical cancer became the third most common cancer among women, and genome characterization of cervical cancer patients has revealed the extensive complexity of molecular alterations. However, identifying driver mutation and depicting molecular classification in cervical cancer remain a challenge.

Methods: We performed an integrative multi-platform analysis of a cervical cancer cohort from The Cancer Genome Atlas (TCGA) based on 284 clinical cases and identified the driver genes and possible molecular classification of cervical cancer.

Results: Multi-platform integration showed that cervical cancer exhibited a wide range of mutation. The top 10 mutated genes were TTN, PIK3CA, MUC4, KMT2C, MUC16, KMT2D, SYNE1, FLG, DST, and EP300, with a mutation rate from 12 to 33%. Applying GISTIC to detect copy number variation (CNV), the most frequent chromosome arm-level CNVs included losses in 4p, 11p, and 11q and gains in 20q, 3q, and 1q. Then, we performed unsupervised consensus clustering of tumor CNV profiles and methylation profiles and detected four statistically significant expression subtypes. Finally, by combining the multidimensional datasets, we identified 10 potential driver genes, including GPR107, CHRNA5, ZBTB20, Rb1, NCAPH2, SCA1, SLC25A5, RBPMS, DDX3X, and H2BFM.

Conclusions: This comprehensive analysis described the genetic characteristic of cervical cancer and identified novel driver genes in cervical cancer. These results provide insight into developing precision treatment in cervical cancer.

Targeting kinases with thymoquinone: a molecular approach to cancer therapeutics

Kinases are enzymes that are important for cellular functions, but their overexpression has strong connections with carcinogenesis, rendering them important targets for anticancer drugs. Thymoquinone (TQ) is a natural compound with proven anticancer activities, at least in preclinical studies. TQ can target several kinases, including phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), polo-like kinase 1 (PLK1), and tyrosine kinase in different cancer cells and animal models. Inhibiting the activity of kinases or suppressing their expression might be among the mechanisms of TQ anticancer activity. In this review, we discuss the role of TQ in kinase regulation in different cancer models.

Whole-exome and RNA sequencing of pulmonary carcinoid reveals chromosomal rearrangements associated with recurrence

INTRODUCTION

The majority of pulmonary carcinoid (PC) tumors can be cured by surgical resection alone, but a significant proportion of patients experience recurrence. As PC is insensitive to conventional chemotherapy, further clarification of the molecular mechanisms of metastasis is needed in order to develop targeted therapeutics.

METHODS

We performed comprehensive whole-exome sequencing (WES) of primary tumors and corresponding normal lung tissues from 14 PC patients (including 4 patients who developed postsurgical distant metastasis) and RNA sequencing of primary tumors from 6 PC patients (including 4 patients who developed postsurgical distant metastasis). Exon array-based gene expression analysis was performed in 25 cases of PC.

RESULTS

We identified a total of 139 alterations in 136 genes. MUC6 and SPTA1 were recurrently mutated at a frequency of 21% (3/14) and 14% (2/14), respectively. Mucin protein family genes including MUC2, MUC4 and MUC6 were mutated in a mutually exclusive manner in 36% (5/14). Pathway analysis of the mutated genes revealed enrichment of genes involved in mitogen-activated protein kinase (MAPK) signaling, regulation of the actin cytoskeleton and focal adhesion, and transforming growth factor (TGF)-β signaling. RNA sequencing revealed a total of 8 novel fusion transcripts including one derived from a chromosomal translocation between the TRIB2 and PRKCE genes. All of the 8 fusion genes were detected in primary PCs that had developed metastasis after surgical resection. We identified 14 genes (DENND1B, GRID1, CLMN, DENND1B, NRP1, SEL1L3, C5orf13, TNFRSF21, TES, STK39, MTHFD2, OPN3, MET, and HIST1H3C) up-regulated in 5 PCs that had relapsed after surgical resection.

CONCLUSIONS

In this study we identified novel somatic mutations and chromosomal rearrangements in PC by examining clinically aggressive cases that had developed postsurgical metastasis. It will be essential to validate the clinical significance of these genetic changes in a larger independent patient cohort.

Mucin glycoproteins block apoptosis; promote invasion, proliferation, and migration; and cause chemoresistance through diverse pathways in epithelial cancers

Overexpression of mucin glycoproteins has been demonstrated in many epithelial-derived cancers. The significance of this overexpression remains uncertain. The aim of this paper was to define the association of mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers by performing a systematic review of all published data. A systematic review of PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed to identify all papers that evaluated the association between mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers. PRISMA guidelines were adhered to. Results of individual studies were extracted and pooled together based on the organ in which the cancer was derived from. The initial search revealed 2031 papers, of which 90 were deemed eligible for inclusion in the study. The studies included details on MUC1, MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16. The majority of studies evaluated MUC1. MUC1 overexpression was consistently associated with resistance to apoptosis and resistance to chemotherapy. There was also evidence that overexpression of MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16 conferred resistance to apoptosis in epithelial-derived cancers. The overexpression of mucin glycoproteins is associated with resistance to apoptosis in numerous epithelial cancers. They cause resistance through diverse signaling pathways. Targeting the expression of mucin glycoproteins represents a potential therapeutic target in the treatment of epithelial-derived cancers.

Assessing the prognostic significance of MUC4β in mucoepidermoid carcinoma of the salivary glands: An immunohistochemical study

Objectives

– Routine histopathological grading for salivary gland mucoepidermoid carcinoma (MEC) have failed to prognosticate these tumors, resulting in poor post-surgical outcomes. In developing countries, the lack of technologically advanced infrastructure curtails, efficient treatment modalities. This study aimed at determining if MUC4β can characterize salivary gland MEC and serve as a practical and inexpensive method to prognosticate salivary gland MEC.

Materials and methods

– Fifteen cases of archived paraffin embedded tissue blocks of mucoepidermoid carcinomas were reassessed for histopathological grading using Healey's system, modified by Batsakis and Luna and immunohistochemically evaluated for expression of MUC4β. Statistical analysis (Kappa statistics and Spearman's rho correlation coefficient) was performed to assess inter-observer reproducibility and to correlate the expression of MUC4β with the histopathological grade of the tumor.

Results

MUC4β expression is related to tumor differentiation in an inverse relationship. Two cases of high grade MEC were the exception to this rule.

Conclusion

Our study revealed that MUC4β alone cannot serve as a reliable prognostic marker due to its divergent tumor suppressor and oncogenic pathway. The role of MUC4β needs further evaluation and research so as to potentiate therapeutics depending upon its context dependent function, as a cancer marker or an oncogenic factor.

MUC4-ErbB2 Oncogenic Complex: Binding studies using Microscale Thermophoresis

The MUC4 membrane-bound mucin is a large O-glycoprotein involved in epithelial homeostasis. At the cancer cell surface MUC4 interacts with ErbB2 receptor via EGF domains to promote cell proliferation and migration. MUC4 is highly regarded as a therapeutic target in pancreatic cancer as it is not expressed in healthy pancreas, while it is neoexpressed in early preneoplastic stages (PanINs). However, the association/dissociation constant of MUC4-ErbB2 complex is unknown. Protein-protein interactions (PPIs) have become a major area of research in the past years and the characterization of their interactions, especially by biophysical methods, is intensively used in drug discovery. To characterize the MUC4-ErbB2 interaction, we used MicroScale Thermophoresis (MST), a powerful method for quantitative protein interaction analysis under challenging conditions. We worked with CHO cell lysates containing either the transmembrane β subunit of MUC4 (MUC4β) or a truncated mutant encompassing only the EGF domains (MUC4_EGF3+1+2). MST studies have led to the characterization of equilibrium dissociation constants (K_d) for MUC4β-ErbB2 (7–25 nM) and MUC4_EGF3+1+2/ErbB2 (65–79 nM) complexes. This work provides new information regarding the MUC4-ErbB2 interaction at the biophysical level and also confirms that the presence of the three EGF domains of MUC4 is sufficient to provide efficient interaction. This technological approach will be very useful in the future to validate small molecule binding affinities targeting MUC4-ErbB2 complex for drug discovery development in cancer. It will also be of high interest for the other known membrane mucins forming oncogenic complexes with ErbBs at the cancer cell surface.

Biosensors for early diagnosis of pancreatic cancer: a review

Pancreatic cancer is characterized by extremely high mortality and poor prognosis and is projected to be the leading cause of cancer deaths by 2030. Due to the lack of early symptoms and appropriate methods to detect pancreatic carcinoma at an early stage as well as its aggressive progression, the disease is often quite advanced by the time a definite diagnosis is established. The 5-year relative survival rate for all stages is approximately 8%. Therefore, detection of pancreatic cancer at an early surgically resectable stage is the key to decrease mortality and to improve survival. The traditional methods for diagnosing pancreatic cancer involve an imaging test, such as ultrasound or magnetic resonance imaging, paired with a biopsy of the mass in question. These methods are often expensive, time consuming, and require trained professionals to use the instruments and analyze the imaging. To overcome these issues, biosensors have been proposed as a promising tool for the early diagnosis of pancreatic cancer. The present review critically discusses the latest developments in biosensors for the early diagnosis of pancreatic cancer. Protein and microRNA biomarkers of pancreatic cancer and corresponding biosensors for pancreatic cancer diagnosis have been reviewed, and all these cases demonstrate that the emerging biosensors are becoming an increasingly relevant alternative to traditional techniques. In addition, we discuss the existing problems in biosensors and future challenges.

Selective targeting of signet ring cell adenocarcinomas

Many epithelial tumors, especially signet-ring cell adenocarcinomas, produce huge amounts of mucin glycoproteins that fill cytoplasm and push nucleus to the periphery, giving a signet ring like structure to the cell. Mucin proteins are very rich of l-threonine which is essential in humans. L-threonine content can reach up to 35% of total amino acid composition of some mucin proteins. Therefore l-threonine can be the Achilles heel of signet ring cell adenocarcinomas which are one of the most malignant and agressive cancers. A modified bioisoster of l-threonine, 4-fluoro l-threonine (its fluorine can be radioactive or not), can be used to selectively kill signet ring cancer cells without harming normal cells or for diagnostic purposes.

The pan-cancer analysis of gain-of-functional mutations to identify the common oncogenic signatures in multiple cancers

Oncogenes can potentially cause uncontrolled cell growth, leading to cancer development, and these genes are normally mutated and over-expressed in tumor cells. Genomic alteration of oncogenes might result in oncogenesis and promotion of cancer progression. To date, researchers have focused mainly on the roles of oncogenes in particular cancers, but investigation of oncogenes with gain-of-function mutations in multiple cancer types are less represented in the literature. Furthermore, the effect of those gain-of-function are not validated in gene expression level. To meet this demand, we performed a systematic analysis of gene expression in oncogenes to identify the occurrence of gain-of-function mutations in pan-cancer. We identified 33,551 oncogenic mutations in 5000 samples. From our analysis, we identified three tissues with the highest frequency of gain-of-functional oncogenic mutations in hundreds of samples: breast (739 samples), central nervous system (646 samples) and large intestine (498 samples). By further counting the number of occurrences of oncogenes across cancer types, we identified a list cross-cancer mutational signatures of 99 oncogenes highly mutated in >400 samples in breast, central nervous system and large intestine samples. By further overlapping with gene expression data in the matched tumor samples, we further identified 1875 gain-of-functional mutations/events with consistent gene up-regulation in 1031 samples from multiple cancers. This result may offer additional insight into the relationship between gene dosage and oncogenesis and maybe useful in targeted cancer therapy. In summary, this study provides the first globally examining on the genetic alteration of oncogenes across cancer types. Clinical association analysis has shown that these 99 genes have a significant effect on survival.

Cancer: Thymoquinone antioxidant/pro-oxidant effect as potential anticancer remedy

Recently, there is growing interest in the natural bioactive components having anticancer activity. Thymoquinone (TQ), the principle active constituent of black seed (Nigella sativa), has promising properties including anticancer and chemosensitizing peculiarities. The anticancer power of TQ is accomplished by several aspects; including promotion of apoptosis, arrest of cell cycle and ROS generation. In addition, it boosts the immune system and lessens the side effects associated with traditional anticancer therapy. TQ also controls angiogenesis and cancer metastasis. This review focuses on the potential aspects and mechanisms by which TQ acquires its actions.

A Tumor-Selective Monoclonal Antibody from Immunization with a Tumor-Associated Mucin Glycopeptide

We have previously studied the generation of immune responses after vaccination with tumor-associated carbohydrate antigen (TACA)-containing glycopeptides from the tandem repeat (TR) sequence of MUC4, an aberrantly expressed mucin in pancreatic adenocarcinomas. A specific lead antigen from that study containing the Thomsen-Friedenreich TACA disaccharide facilitated the pursuit of a monoclonal antibody to this synthetic hapten. Initial evaluation of polyclonal antiserum resulting from immunization with a KLH conjugate of this glycopeptide into rabbits showed high titer antibodies by ELISA assays, and selective immunoreactivity with MUC4+ cells by western blot and flow cytometry techniques. Glycan microarray analysis showed an intriguing binding pattern where the antiserum showed near complete specificity for MUC4 TR glycopeptides and peptides, relative to all components on the array. Tissue staining also showed distinct tumor specificity to pancreatic tumor tissue in relation to normal pancreatic tissue, with a preference for more aggressive tumor foci. Based on this data, we produced a monoclonal antibody whose binding and reactivity profile was similar to that of the polyclonal serum, with the added benefit of being more specific for the N-terminal glycosylated peptide domain. This epitope represents a novel immunogen to potentially develop diagnostic antibodies or immunotherapies against various MUC4-positive cancers.

Glycosylation markers in cancer

Alteration of glycosylation, a hallmark of cancer, results in the production of tumor-associated glycans or glycoproteins. These molecules are subsequently secreted or membrane-shed into the blood stream and thus serve as tumor-associated markers. Increased glycosylation in cancer is triggered by overexpression of glycoproteins that carry certain specific glycans, increase or decrease of nucleotide sugar donors and altered expression of glycosyltransferase and glycosidase enzymes. In this chapter, the biochemistry and function of glycoprotein, glycan and enzyme markers are reviewed. These glycosylation markers, applicable for detection and monitoring of cancer, include CA19-9, CA125, CEA, PSA and AFP. Because of their specific affinity to distinct sugar moieties, lectins are useful for developing assays to detect these tumor associated glycans and glycoproteins in clinical samples. As such, various enzyme-linked lectin assays (ELLA) have been developed for diagnosis, monitoring and prognosis. Because glycosylation changes occur early in cancer, the detection of tumor associated glycosylation markers using lectin based assays is an effective strategy to improve diagnosis and treatment resulting better outcomes clinically.

Axed MUC4 (MUC4/X) aggravates pancreatic malignant phenotype by activating integrin-β1/FAK/ERK pathway

Alternative splicing is evolving as an eminent player of oncogenic signaling for tumor development and progression. Mucin 4 (MUC4), a type I membrane-bound mucin, is differentially expressed in pancreatic cancer (PC) and plays a critical role in its progression and metastasis. However, the molecular implications of MUC4 splice variants during disease pathogenesis remain obscure. The present study delineates the pathological and molecular significance of a unique splice variant of MUC4, MUC4/X, which lacks the largest exon 2, along with exon 3. Exon 2 encodes for the highly glycosylated tandem repeat (TR) domain of MUC4 and its absence creates MUC4/X, which is devoid of TR. Expression analysis from PC clinical samples revealed significant upregulation of MUC4/X in PC tissues with most differential expression in poorly differentiated tumors. In vitro studies suggest that overexpression of MUC4/X in wild-type-MUC4 (WT-MUC4) null PC cell lines markedly enhanced PC cell proliferation, invasion, and adhesion to extracellular matrix (ECM) proteins. Furthermore, MUC4/X overexpression leads to an increase in the tumorigenic potential of PC cells in orthotopic transplantation studies. In line with these findings, doxycycline-induced expression of MUC4/X in an endogenous WT-MUC4 expressing PC cell line (Capan-1) also displayed enhanced cell proliferation, invasion, and adhesion to ECM, compared to WT-MUC4 alone, emphasizing its direct involvement in the aggressive behavior of PC cells. Investigation into the molecular mechanism suggested that MUC4/X facilitated PC tumorigenesis via integrin-β1/FAK/ERK signaling pathway. Overall, these findings revealed the novel role of MUC4/X in promoting and sustaining the oncogenic features of PC.

NIDO, AMOP and vWD domains of MUC4 play synergic role in MUC4 mediated signaling

MUC4 mucin is well known as an important potential target to overcome pancreatic cancer. Three unique domains (NIDO, AMOP, and vWD) with unclear roles only present in MUC4 but are not found in other membrane-bound mucins. Our previous studies first reported that its splice variant, MUC4/Y can be a model of MUC4 (MUC4 gene fragment is more than 30KB, too huge to clone and eukaryotic express) in pancreatic cancer. More importantly, based on MUC4/Y with the appropriate length of gene sequence, it is easy to construct the unique domain-lacking models of MUC4/Y (MUC4) for research. The present study focuses on investigation of the respective role of the unique NIDO, AMOP, and vWD domain or their synergistic effect on MUC4(MUC4/Y)-mediated functions and mechanisms by series of in vitro assays, sequence-based transcriptome analysis, validation of qRT-PCR & Western blot, and systematic comparative analysis. Our results demonstrate: 1) NIDO, AMOP, and vWD domain or their synergy play significant roles on MUC4/Y-mediated malignant function of pancreatic cancer, downstream of molecule mechanisms, particularly MUC4/Y-triggered malignancy-related positive feedback loops, respectively. 2) The synergistic roles of three unique domains on MUC4/Y-mediated functions and mechanisms are more prominent than the respective domain because the synergy of three domain plays the more remarkable effects on MUC4/Y-mediated signaling hub. Thus, to improve reversed effects of domain-lacking and break the synergism of domains will contribute to block MUC4/Y(MUC4) triggering various oncogenic signaling pathways.

Aberrant methylation of MUC1 and MUC4 promoters are potential prognostic biomarkers for pancreatic ductal adenocarcinomas

Pancreatic cancer is still a disease of high mortality despite availability of diagnostic techniques. Mucins (MUC) play crucial roles in carcinogenesis and tumor invasion in pancreatic neoplasms. MUC1 and MUC4 are high molecular weight transmembrane mucins. These are overexpressed in many carcinomas, and high expression of these molecules is a risk factor associated with poor prognosis. We evaluated the methylation status of MUC1 and MUC4 promoter regions in pancreatic tissue samples from 169 patients with various pancreatic lesions by the methylation specific electrophoresis (MSE) method. These results were compared with expression of MUC1 and MUC4, several DNA methylation/demethylation factors (e.g. ten-eleven translocation or TET, and activation-induced cytidine deaminase or AID) and CAIX (carbonic anhydrase IX, as a hypoxia biomarker). These results were also analyzed with clinicopathological features including time of overall survival of PDAC patients. We show that the DNA methylation status of the promoters of MUC1 and MUC4 in pancreatic tissue correlates with the expression of MUC1 and MUC4 mRNA. In addition, the expression of several DNA methylation/demethylation factors show a significant correlation with MUC1 and MUC4 methylation status. Furthermore, CAIX expression significantly correlates with the expression of MUC1 and MUC4. Interestingly, our results indicate that low methylation of MUC1 and/or MUC4 promoters correlates with decreased overall survival. This is the first report to show a relationship between MUC1 and/or MUC4 methylation status and prognosis. Analysis of epigenetic changes in mucin genes may be of diagnostic utility and one of the prognostic predictors for patients with PDAC.

Anti-cancer properties and mechanisms of action of thymoquinone, the major active ingredient of Nigella sativa

Over the past two decades, studies have documented the wide-range anti-cancer effects of Nigella sativa, known as black seed or black cumin. Thymoquinone (TQ), its major active ingredient, has also been extensively studied and reported to possess potent anti-cancer properties. Herein, we provide a comprehensive review of the findings related to the anti-cancer activity of TQ. The review focuses on analyzing experimental studies performed using different in vitro and in vivo models to identify the anti-proliferative, pro-apoptotic, anti-oxidant, cytotoxic, anti-metastatic, and NK-dependent cytotoxic effects exerted by TQ. In addition, we pinpoint the molecular mechanisms underlying these effects and the signal transduction pathways implicated by TQ. Our analysis show that p53, NF-κB, PPARγ, STAT3, MAPK, and PI3K/AKT signaling pathways are among the most significant pathways through which TQ mediates its anti-cancer activity. Experimental findings and recent advances in the field highlight TQ as an effective therapeutic agent for the suppression of tumor development, growth and metastasis for a wide range of tumors.

Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets

Mucins are the main structural components of mucus that create a selective protective barrier for epithelial surface and also execute wide range of other physiological functions. Mucins can be classified into two types, namely secreted mucins and membrane bounded mucins. Alterations in mucin expression or glycosylation and mislocalization have been seen in various types of pathological conditions such as cancers, inflammatory bowel disease and ocular disease, which highlight the importance of mucin in maintaining homeostasis. Hence mucins can be used as attractive target for therapeutic intervention. In this review, we discuss in detail about the structural diversity of mucins; their biosynthesis; its role in pathogenesis; regulation and as possible therapeutic targets.

Comprehensive Analysis of Cancer-Proteogenome to Identify Biomarkers for the Early Diagnosis and Prognosis of Cancer

During the past century, our understanding of cancer diagnosis and treatment has been based on a monogenic approach, and as a consequence our knowledge of the clinical genetic underpinnings of cancer is incomplete. Since the completion of the human genome in 2003, it has steered us into therapeutic target discovery, enabling us to mine the genome using cutting edge proteogenomics tools. A number of novel and promising cancer targets have emerged from the genome project for diagnostics, therapeutics, and prognostic markers, which are being used to monitor response to cancer treatment. The heterogeneous nature of cancer has hindered progress in understanding the underlying mechanisms that lead to abnormal cellular growth. Since, the start of The Cancer Genome Atlas (TCGA), and the International Genome consortium projects, there has been tremendous progress in genome sequencing and immense numbers of cancer genomes have been completed, and this approach has transformed our understanding of the diagnosis and treatment of different types of cancers. By employing Genomics and proteomics technologies, an immense amount of genomic data is being generated on clinical tumors, which has transformed the cancer landscape and has the potential to transform cancer diagnosis and prognosis. A complete molecular view of the cancer landscape is necessary for understanding the underlying mechanisms of cancer initiation to improve diagnosis and prognosis, which ultimately will lead to personalized treatment. Interestingly, cancer proteome analysis has also allowed us to identify biomarkers to monitor drug and radiation resistance in patients undergoing cancer treatment. Further, TCGA-funded studies have allowed for the genomic and transcriptomic characterization of targeted cancers, this analysis aiding the development of targeted therapies for highly lethal malignancy. High-throughput technologies, such as complete proteome, epigenome, protein-protein interaction, and pharmacogenomics data, are indispensable to glean into the cancer genome and proteome and these approaches have generated multidimensional universal studies of genes and proteins (OMICS) data which has the potential to facilitate precision medicine. However, due to slow progress in computational technologies, the translation of big omics data into their clinical aspects have been slow. In this review, attempts have been made to describe the role of high-throughput genomic and proteomic technologies in identifying a panel of biomarkers which could be used for the early diagnosis and prognosis of cancer.

Cell membrane-anchored MUC4 promotes tumorigenicity in epithelial carcinomas

The cell surface membrane-bound mucin protein MUC4 promotes tumorigenicity, aggressive behavior, and poor outcomes in various types of epithelial carcinomas, including pancreatic, breast, colon, ovarian, and prostate cancer. This review summarizes the theories and findings regarding MUC4 function, and its role in epithelial carcinogenesis. Based on these insights, we developed an outline of the processes and mechanisms by which MUC4 critically supports the propagation and survival of cancer cells in various epithelial organs. MUC4 may therefore be a useful prognostic and diagnostic tool that improves our ability to eradicate various forms of cancer.

Effects of dietary resveratrol supplementation on hepatic and serum pro-/anti-inflammatory activity in juvenile GIFT tilapia, Oreochromis niloticus

Dietary resveratrol (RES) supplementation may have some pharmacological effects including anti-inflammation. Previous studies have shown that Kupffer cell activation and apoptosis induction increases the transcription of pro- and anti-inflammatory cytokines. The main purpose of this study was to investigate the pro- and anti-inflammatory activities of 0.1 or 0.3 g/kg RES as a dietary supplement in juvenile freshwater tilapia (Oreochromis niloticus). The results showed that hepatic and serum immunoglobulin M (IgM) significantly decreased and increased while anti- and pro-inflammatory cytokines significantly increased and decreased, respectively, in the RES-treated groups. The expression of serum and hepatic IgM and anti-inflammatory cytokines [interleukin (IL)-10] and its inverse inhibitor interferon (IFN)-γ significantly increased while pro-inflammatory cytokine transcription significantly decreased. Hematoxylin-eosin staining and scanning electron microscopy revealed intestinal deformation, irregular goblet cells, and apoptotic cells in the 0.3 g/kg RES groups. RES (0.3 g/kg) also induced necrosis, apoptosis, reduction in Kupffer cell number, compressed sinusoids, and deformation of epidermal cells in the liver of the treated groups. In conclusion, the results of the present study show that high doses of RES were absorbed in the gut and then damaged the liver and intestinal tissue.

Impacts of Early Life Stress on the Methylome and Transcriptome of Atlantic Salmon

Exposure to environmental stressors during early-life stages can change the rate and timing of various developmental processes. Epigenetic marks affecting transcriptional regulation can be altered by such environmental stimuli. To assess how stress might affect the methylome and transcriptome in salmon, fish were treated using cold-shock and air-exposure from the eye-stage until start-feeding. The fish were either stressed prior to hatching (E), post-hatching (PH), pre- and post-hatching (EPH) or not stressed (CO). Assessing transcriptional abundances just prior to start feeding, E and PH individuals were found to have modified the expression of thousands of genes, many with important functions in developmental processes. The EPH individuals however, showed expression similar to those of CO, suggesting an adaptive response to extended periods of stress. The methylome of stressed individuals differed from that of the CO, suggesting the importance of environment in shaping methylation signatures. Through integration of methylation with transcription, we identified bases with potential regulatory functions, some 10s of kb away from the targeted genes. We then followed fish growth for an additional year. Individuals in EPH showed superior growth compared to other treatment groups, highlighting how stress can potentially have long-lasting effects on an organism's ability to adapt to environmental perturbations.

Clinicopathological Study of Carcinoma of the Ampulla of Vater with Special Reference to MUC1, MUC2 and MUC5AC Expression

INTRODUCTION

The ampulla of Vater consists of papilla, common channel, distal common bile duct and the distal main pancreatic duct. Ampullary carcinomas arise from two different types of mucosa, reflecting their broad histomorphological spectrum. Adenocarcinomas originating in the ampulla of Vater are classified as having either 'Intestinal' or 'Pancreatobiliary' type of differentiation. Pancreatobiliary type has consistently shown a worse prognosis. Various types of mucins are distributed in normal tissues and gastrointestinal tumours. MUC1, MUC2 and MUC5AC are known to be the most important amongst all.

AIM

To study clinicopathological features of different types of carcinoma of ampulla with MUC1, MUC2 and MUC5AC expression.

MATERIALS AND METHODS

We included 20 cases of ampullary adenocarcinoma in this study, diagnosed after radical surgery. The histopathological slides were reviewed and the tumours were classified into intestinal type, pancreatobilliary and other types. Representative block of tumours was subjected to immunohistochemical (IHC) study with MUC1, MUC2 and MUC5AC antibodies. Results were subsequently analysed.

RESULTS

Pancreaticobiliary type of ampullary carcinoma cases predominated (50%) over intestinal type (25%). Carcinomas of "other types" included one case each of mucinous carcinoma, adenosquamous carcinoma and undifferentiated carcinoma and well differentiated neuroendocrine tumours. Pancreatobiliary type of carcinomas was associated with higher tumour stage and grade and lymph node metastasis. All the pancreatobiliary type expressed MUC1 and all intestinal type carcinomas expressed MUC2. MUC 5AC expression was seen predominantly in pancreatobiliary type of ampullary carcinomas.

CONCLUSION

Mucin markers are associated with two different subtypes of ampullary carcinomas which have different prognosis. Immunohistochemical study of mucin expression can define the different types of carcinomas of ampulla of Vater with better objective criteria.

TET1-mediated DNA hypomethylation regulates the expression of MUC4 in lung cancer

Lung cancer remains a disease of high mortality, despite advanced diagnostic techniques. Mucins (MUC) play crucial roles in carcinogenesis and tumor invasion in lung neoplasms. Our immunohistochemistry (IHC) studies have shown that high MUC4 expression correlates with a poor outcome. We have also shown that the expression of several mucin genes in cancer cell lines is regulated by DNA methylation. We evaluated the expression level of MUC4, mRNA and several DNA hypomethylation factors in lung tissue samples from 33 patients with various lung lesions. The results indicated that the DNA methylation status of MUC4 matched the expression level of mRNA. In addition, the TET1 (Ten-Eleven Translocation) mRNA showed a significant correlation with the status of DNA methylation of MUC4. Furthermore, the treatment of a lung cancer cell line with TET1 siRNA caused a reduction in MUC4 mRNA expression. Thus, we suggest that TET1 mediated DNA hypomethylation plays a key role in the expression of MUC4. This is the first report that TET1 mediated DNA hypomethylation regulates the expression of MUC4 in lung cancer. The analysis of these epigenetic changes may be useful for diagnosing carcinogenic risk.

MUC4 mucin- a therapeutic target for pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic cancer (PC) is characterized by mucin overexpression. MUC4 is the most differentially overexpressed membrane-bound mucin that plays a functional role in disease progression and therapy resistance. Area covered: We describe the clinicopathological significance of MUC4, summarize mechanisms contributing to its deregulated expression, review preclinical studies aimed at inhibiting MUC4, and discuss how MUC4 overexpression provides opportunities for developing targeted therapies. Finally, we discuss the challenges for developing MUC4-based therapeutics, and identify areas where efforts should be directed to effectively exploit MUC4 as a therapeutic target for PC. Expert opinion: Studies demonstrating that abrogation of MUC4 expression reduces proliferation and metastasis of PC cells and enhances sensitivity to therapeutic agents affirm its utility as a therapeutic target. Emerging evidence also supports the suitability of MUC4 as a potential immunotherapy target. However, these studies have been limited to in vitro, ex vivo or in vivo approaches using xenograft tumors in immunodeficient murine models. For translational relevance, MUC4-targeted therapies should be evaluated in murine models with intact immune system and accurate tumor microenvironment. Additionally, future studies evaluating MUC4 as a target for immunotherapy must entail characterization of immune response in PC patients and investigate its association with immunosuppression and survival.

Genomic alterations in mucins across cancers

The significance of mucins in cancers has led to the development of novel biomarkers and therapeutic agents against cancers. Despite significant advances in the understanding of mucins, systemic investigations into the role of mucins in cancer biology focusing particularly on the histological subtypes and stages, along with other variables, are yet to be carried out to discover potential novel functions and cancer-specific roles. Here, we investigated 11 mucin expressing cancers for DNA mutations, mRNA expression, copy number, methylation, and the impacts these genomic features may have on patient survival by utilizing The Cancer Genome Atlas dataset. We demonstrate that mucin DNA mutations have a significant rate, pattern, and impact on cancer patient survival depending on the tissue of origin. This includes a frequent T112P mutation in MUC1 that is seen in half of the pancreatic MUC1 mutations, as well as being present in other cancers. We also observed a very frequent MUC4 mutation at H4205, which correlated with survival outcomes in patients. Furthermore, we observed significant alterations in mucin mRNA expression in multiple tumor types. Our results demonstrate de novo expression of certain mucins in cancer tissues, including MUC21 in colorectal cancers. We observed a general decrease in promoter methylation for mucins, which correlated with decreased expression of many genes, such as MUC15 in kidney cancers. Lastly, several mucin gene loci demonstrated copy number increase in multiple histological subtypes. Thus, our study presents a comprehensive analysis of genomic alterations in mucins and their corresponding roles in cancer progression.

N-Acetylcysteine breaks resistance to trastuzumab caused by MUC4 overexpression in human HER2 positive BC-bearing nude mice monitored by 89Zr-Trastuzumab and 18F-FDG PET imaging

Trastuzumab remains an important drug in the management of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer (BC). Several studies reported resistance mechanisms to trastuzumab, including impaired HER2-accessibility caused by mucin 4 (MUC4). Previously, we demonstrated an increase of Zirconium-89-radiolabeled-trastuzumab (⁸⁹Zr-Trastuzumab) accumulation when MUC4-overexpressing BC-cells were challenged with the mucolytic drug N-Acetylcysteine (NAC). Hereby, using the same approach we investigated whether tumor exposure to NAC would also enhance trastuzumab-efficacy.

Dual SKBr3 (HER2+/MUC4-, sensitive to trastuzumab) and JIMT1 (HER2+/MUC4+, resistant to trastuzumab) HER2-BC-bearing-xenografts were treated with trastuzumab and NAC. Treatment was monitored by molecular imaging evaluating HER2-accessibility/activity (⁸⁹Zr-Trastuzumab HER2-immunoPET) and glucose metabolism (¹⁸F-FDG-PET/CT), as well as tumor volume and the expression of key proteins.

In the MUC4-positive JIMT1-tumors, the NAC-trastuzumab combination resulted in improved tumor-growth control compared to trastuzumab alone; with smaller tumor volume/weight, lower 18F-FDG uptake, lower %Ki67 and pAkt-expression. NAC reduced MUC4-expression, but did not affect HER2-expression or the trastuzumab-sensitivity of the MUC4-negative SKBr3-tumors.

These findings suggest that improving HER2-accessibility by reducing MUC4-masking with the mucolytic drug NAC, results in a higher anti-tumor effect of trastuzumab. This provides a rationale for the potential benefit of this approach to possibly treat a subset of HER2-positive BC overexpressing MUC4.

Cell growth inhibition and apoptotic effects of a specific anti-RTFscFv antibody on prostate cancer, but not glioblastoma, cells

Background: Single chain antibody (scFv) has shown interesting results in cancer immunotargeting approaches, due to its advantages over monoclonal antibodies. Regeneration and tolerance factor (RTF) is one of the most important regulators of extracellular and intracellular pH in eukaryotic cells. In this study, the inhibitory effects of a specific anti-RTF scFv were investigated and compared between three types of prostate cancer and two types of glioblastoma cells.  Methods: A phage antibody display library of scFv was used to select specific scFvs against RTF using panning process. The reactivity of a selected scFv was assessed by phage ELISA. The anti-proliferative and apoptotic effects of the antibody on prostate cancer (PC-3, Du-145 and LNCaP) and glioblastoma (U-87 MG and A-172) cell lines were investigated by MTT and Annexin V/PI assays.  Results: A specific scFv with frequency 35% was selected against RTF epitope. This significantly inhibited the proliferation of the prostate cells after 24 h. The percentages of cell viability (using 1000 scFv/cell) were 52, 61 and 73% for PC-3, Du-145 and LNCaP cells, respectively, compared to untreated cells. The antibody (1000 scFv/cell) induced apoptosis at 50, 40 and 25% in PC-3, Du-145 and LNCaP cells, respectively. No growth inhibition and apoptotic induction was detected for U-87 and A172 glioblastoma cells.  Conclusions: Anti-RTFscFv significantly reduced the proliferation of the prostate cancer cells. The inhibition of cell growth and apoptotic induction effects in PC-3 cells were greater than Du-145 and LNCaP cells. This might be due to higher expression of RTF antigen in PC-3 cells and/or better accessibility of RTF to scFv antibody. The resistance of glioblastoma cells to anti-RTF scFv offers the existence of mechanism(s) that abrogate the inhibitory effect(s) of the antibody to RTF. The results suggest that the selected anti-RTF scFv antibody could be an effective new alternative for prostate cancer immunotherapy.

Exhaled breath condensate analysis from intubated newborns by nano-HPLC coupled to high resolution MS

Invasiveness of examination and therapy methods is a serious problem for intensive care and nursing of premature infants. Exhaled breath condensate (EBC) is the most attractive biofluid for non-invasive methods development in neonatology for monitoring the status of intubated infants. The aim of the study was to propose an approach for EBC sampling and analysis from mechanically ventilated neonates. EBC collection system with good reproducibility of sampling was demonstrated. Discovery-based proteomic and metabolomic studies were performed using nano-HPLC coupled to high resolution MS. Label-free semi-quantitative data were compared for intubated neonates with congenital pneumonia (12 infants) and left-sided congenital diaphragmatic hernia (12 infants) in order to define disease-specific features. Totally 119 proteins and 164 metabolites were found. A number of proteins and metabolites that can act as potential biomarkers of respiratory diseases were proposed and require further validation.

MiR-211 inhibits invasion and epithelial-to-mesenchymal transition (EMT) of cervical cancer cells via targeting MUC4

The dysregulated molecules and their involvement in lymph node metastases of cervical cancer are far from been fully revealed. In this study, by reviewing MUC4 expression in The Human Protein Atlas and retrieving gene microarray data in GEO dataset (No. GDS4664), we found that MUC4 upregulation is associated with lymph node metastasis in cervical cancer. Knockdown of MUC4 in Hela and SiHa cells significantly reduced their invasion and also reduced the mesenchymal properties. By performing bioinformatics analysis, we observed that miR-211 is a potential suppressor of MUC4, which has a predicted highly conserved binding site in the 3'UTR of MUC among mammals. The following assays confirmed that miR-211 can directly target the 3'UTR of MUC4 and inhibit its expression at both mRNA and protein levels. In addition, enforced miR-211 expression phenocopies the effects of MUC4 siRNA in inhibiting cervical cancer cell invasion and reversing EMT properties. Therefore, we infer that miR-211 is a novel miRNA with suppressive effect on MUC4 expression and can inhibit cervical cancer cell invasion and EMT.

Glycoproteins and glycoproteomics in pancreatic cancer

Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immuno-response and chemoresistance. Abnormal expression in sugar moieties can impact the function of various glycoproteins, including mucins, surface receptors, adhesive proteins, proteoglycans, as well as their effectors and binding ligands, resulting in an increase in pancreatic cancer invasiveness and a cancer-favored microenvironment. Recent advance in glycoproteomics, glycomics and other chemical biology techniques have been employed to better understand the complex mechanism of glycosylation events and how they orchestrate molecular activities in genomics, proteomics and metabolomics implicated in pancreatic adenocarcinoma. A variety of strategies have been demonstrated targeting protein glycosylation and polysaccharides for diagnostic and therapeutic development.

Mucins in neoplasms of pancreas, ampulla of Vater and biliary system

Tumors of the pancreas, the ampulla of Vater, and the extrahepatic and intrahepatic bile ducts have significant histological similarities due to the common embryonic origin of the pancreatobiliary system. This obviates the need for discovery of biomarkers with diagnostic and prognostic value for these tumors. Mucins, especially MUC-1, -2, -4 and -5AC, are important candidates for developing into such reliable biomarkers. Increased expression of MUC1 occurs in pancreatic ductal adenocarcinomas and is associated with increased degrees of dysplasia in pancreatic intraepithelial neoplasia (PanIN). Positive expression of MUC2 in intraductal papillary mucinus neoplasms (IPMN) of the intestinal type indicates high potential progression to invasive carcinoma with de novo expression of MUC1, while absence of MUC2 expression in IPMNs of gastric type implies low potential to malignant evolution. De novo MUC4 expression correlates to the severity of dysplasia in PanIN and is associated with a poor prognosis in patients with pancreatic ductal adenocarcinomas. In biliary intraepithelial neoplasia (BilIN), increased expression of MUC1 is associated with higher degrees of dysplasia. Intrahepatic cholangiocarcinomas (ICC) are characterized by increased expression of all glycoforms of MUC1. Positive MUC2 expression in intraductal papillary neoplasm of the bile ducts (IPNB) of the intestinal type indicates high malignant potential with de novo expression of MUC1 in the invasive element. Absent MUC2 expression in any degree of BilIN may prove useful in differentiating them from IPNB. De novo expression of MUC4 is associated with poor prognosis in patients with ICC or carcinoma of the extrahepatic bile ducts (EHBDC). High de novo expression of MUC5AC is found in all degrees of BilIN and all types of IPNB and ICC. The MUC5AC is useful in the detection of neoplastic lesions of the bile duct at an early stage. Increased expression of mucin MUC1 in carcinoma of the ampulla of Vater associated with unfavorable behavior of the tumor, such as lymph node metastasis, infiltration of the pancreas and duodenum, advanced TNM classification and worse prognosis. Patients with intra-ampullary papillary-tubular neoplasm (IAPN) of the pancreatobiliary immunophenotype did not show MUC2, while those of the intestinal immunophenotype are MUC2 positive. The expression of MUC4 is associated with poor prognosis in patients with carcinoma of the ampulla of Vater favoring metastasis and making them resistant to apoptosis. Moreover, it appears that MUC4 positivity correlates with recurrence of the tumor. Expression of MUC5AC is associated with the invasive potential of the tumor.

MUC16-mediated activation of mTOR and c-Myc reprograms pancreatic cancer metabolism

MUC16, a transmembrane mucin, facilitates pancreatic adenocarcinoma progression and metastasis. In the current studies, we observed that MUC16 knockdown pancreatic cancer cells exhibit reduced glucose uptake and lactate secretion along with reduced migration and invasion potential, which can be restored by supplementing the culture media with lactate, an end product of aerobic glycolysis. MUC16 knockdown leads to inhibition of mTOR activity and reduced expression of its downstream target c-MYC, a key player in cellular growth, proliferation and metabolism. Ectopic expression of c-MYC in MUC16 knockdown pancreatic cancer cells restores the altered cellular physiology. Our LC-MS/MS based metabolomics studies indicate global metabolic alterations in MUC16 knockdown pancreatic cancer cells, as compared to the controls. Specifically, glycolytic and nucleotide metabolite pools were significantly decreased. We observed similar metabolic alterations that correlated with MUC16 expression in primary tumor tissue specimens from human pancreatic adenocarcinoma cancer patients. Overall, our results demonstrate that MUC16 plays an important role in metabolic reprogramming of pancreatic cancer cells by increasing glycolysis and enhancing motility and invasiveness.

Mice deficient in Muc4 are resistant to experimental colitis and colitis-associated colorectal cancer

MUC4, a large transmembrane mucin normally expressed in the small and large intestine, is differentially expressed during inflammatory and malignant conditions of the colon. However, the expression pattern and the role of MUC4 in colitis and colorectal cancer (CRC) are inconclusive. Therefore, the aim of this study was to understand the role of Muc4 during inflammatory and malignant conditions of the colon. Here, we generated Muc4(-/-) mice and addressed its role in colitis and colitis-associated CRC using dextran sodium sulfate (DSS) and azoxymethane (AOM)-DSS experimental models, respectively. Muc4(-/-) mice were viable, fertile with no apparent defects. Muc4(-/-) mice displayed increased resistance to DSS-induced colitis compared with wild-type (WT) littermates that was evaluated by survival rate, body weight loss, diarrhea and fecal blood score, and histological score. Reduced infiltration of inflammatory cells, that is, CD3(+) lymphocytes and F4/80(+) macrophages was observed in the inflamed mucosa along with reduction in the mRNA levels of inflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α and anti-microbial genes Lysozyme M and SLPI in the colon of Muc4(-/-) mice compared with WT littermates. Compensatory upregulation of Muc2 and Muc3 mucins under basal and DSS treatment conditions partly explains the resistance observed in Muc4(-/-) mice. Accordingly, Muc4(-/-) mice exhibited significantly reduced tumor burden compared with WT mice assessed in a colitis-induced tumor model using AOM/DSS. An increased percentage of Ki67(+) nuclei was observed in the tumors from WT compared with Muc4(-/-) mice suggesting Muc4 to be critical in intestinal cell proliferation during tumorigenesis. Taken together, we conclusively demonstrate for the first time the role of Muc4 in driving intestinal inflammation and inflammation-associated tumorigenesis using a novel Muc4(-/-) mouse model.

Electrochemical Characterization of Protein Adsorption onto YNGRT-Au and VLGXE-Au Surfaces

The adsorption of the proteins CD13, mucin and bovine serum albumin on VLGXE-Au and YNGRT-Au interfaces was monitored by electrochemical impedance spectroscopy in the presence of [Fe(CN)₆]^3−/4−. The hydrophobicity of the Au surface was tailored using specific peptides, blocking agents and diluents. The combination of blocking agents (ethanolamine or n-butylamine) and diluents (hexanethiol or 2-mercaptoethanol) was used to prepare various peptide-modified Au surfaces. Protein adsorption onto the peptide-Au surfaces modified with the combination of n-butylamine and hexanethiol produced a dramatic decrease in the charge transfer resistance, R_ct, for all three proteins. In contrast, polar peptide-surfaces induced a minimal change in R_ct for all three proteins. Furthermore, an increase in R_ct was observed with CD13 (an aminopeptidase overexpressed in certain cancers) in comparison to the other proteins when the VLGXE-Au surface was modified with n-butylamine as a blocking agent. The electrochemical data indicated that protein adsorption may be modulated by tailoring the peptide sequence on Au surfaces and that blocking agents and diluents play a key role in promoting or preventing protein adsorption. The peptide-Au platform may also be used for targeting cancer biomarkers with designer peptides.

Nicotine and oxidative stress induced exomic variations are concordant and overrepresented in cancer-associated genes

Although the connection between cancer and cigarette smoke is well established, nicotine is not characterized as a carcinogen. Here, we used exome sequencing to identify nicotine and oxidative stress-induced somatic mutations in normal human epithelial cells and its correlation with cancer. We identified over 6,400 SNVs, indels and microsatellites in each of the stress exposed cells relative to the control, of which, 2,159 were consistently observed at all nicotine doses. These included 429 nsSNVs including 158 novel and 79 cancer-associated. Over 80% of consistently nicotine induced variants overlap with variations detected in oxidative stressed cells, indicating that nicotine induced genomic alterations could be mediated through oxidative stress. Nicotine induced mutations were distributed across 1,585 genes, of which 49% were associated with cancer. MUC family genes were among the top mutated genes. Analysis of 591 lung carcinoma tumor exomes from The Cancer Genome Atlas (TCGA) revealed that 20% of non-small-cell lung cancer tumors in smokers have mutations in at least one of the MUC4, MUC6 or MUC12 genes in contrast to only 6% in non-smokers. These results indicate that nicotine induces genomic variations, promotes instability potentially mediated by oxidative stress, implicating nicotine in carcinogenesis, and establishes MUC genes as potential targets.

Integrated exon level expression analysis of driver genes explain their role in colorectal cancer

Integrated analysis of genomic and transcriptomic level changes holds promise for a better understanding of colorectal cancer (CRC) biology. There is a pertinent need to explain the functional effect of genome level changes by integrating the information at the transcript level. Using high resolution cytogenetics array, we had earlier identified driver genes by ‘Genomic Identification of Significant Targets In Cancer (GISTIC)’ analysis of paired tumour-normal samples from colorectal cancer patients. In this study, we analyze these driver genes at three levels using exon array data – gene, exon and network. Gene level analysis revealed a small subset to experience differential expression. These results were reinforced by carrying out separate differential expression analyses (SAM and LIMMA). ATP8B1 was found to be the novel gene associated with CRC that shows changes at cytogenetic, gene and exon levels. Splice index of 29 exons corresponding to 13 genes was found to be significantly altered in tumour samples. Driver genes were used to construct regulatory networks for tumour and normal groups. There were rearrangements in transcription factor genes suggesting the presence of regulatory switching. The regulatory pattern of AHR gene was found to have the most significant alteration. Our results integrate data with focus on driver genes resulting in highly enriched novel molecules that need further studies to establish their role in CRC.

Combination of MUC1 and MUC4 expression predicts clinical outcome in patients with oral squamous cell carcinoma

BACKGROUND

Both MUC1 and MUC4 are high molecular weight glycoproteins and are independent indicators of worse prognosis in many human epithelial cancers including oral squamous cell carcinoma (OSCC). However, there has been no investigation of the clinical importance of the co-expression of MUC1 and MUC4 in OSCC. The aim of this study was to evaluate the co-expression profile of MUC1/MUC4 and analyze the prognostic significance in OSCC.

METHODS

We examined the expression profile of MUC1 and MUC4 in OSCC tissues from 206 patients using immunohistochemistry. The co-expression profile of MUC1/MUC4 and its prognostic significance in OSCC was statistically analyzed.

RESULTS

MUC1 and MUC4 overexpression were strongly correlated with each other (p < 0.0001) and a combination of both MUC1 and MUC4 expression was a powerful indicator for tumor aggressiveness such as tumor size (p = 0.014), lymph node metastasis (0.0001), tumor stage (p = 0.006), diffuse invasion (p = 0.028), and vascular invasion (p = 0.014). The MUC1/MUC4 double-positive patients showed the poorest overall and disease-free survival. Multivariate analysis revealed that MUC1/MUC4 double-positivity was the strong independent prognostic factor for overall and disease-free survival (p = 0.007 and (p = 0.0019), in addition to regional recurrence (p = 0.0025).

CONCLUSIONS

Taken together, these observations indicate that the use of a combination of MUC1/MUC4 can predict outcomes for patients with OSCC. This combination is also a useful marker for predicting regional recurrence. MUC1 and MUC4 may be attractive targets for the selection of treatment methods in OSCC.

Pancreatic cancer counterattack: MUC4 mediates Fas-independent apoptosis of antigen-specific cytotoxic T lymphocyte

Tumor-associated MUC4 mucin has considerable potential as an immunotherapy target for pancreatic cancer. In previous studies, we developed dendritic cell (DC) vaccines which elicited MUC4 antigen-specific cytotoxic T lymphocyte (MS-CTL) response against tumor cells in vitro. Due to the observation that MS-CTL apoptotic rate increased significantly when co-cultured with MUC4+ tumor cells compared with T2 cells, we investigated whether high expression levels of MUC4 in pancreatic cancer cells would have an effect on the significant increase of apoptosis rate of MS-CTLs. First, the adverse influence of regulatory T cells (Tregs) was eliminated by CD8+ T lymphocyte sorting before the induction of MS-CTLs. Then, we constructed clonal MUC4-knockdown HPAC pancreatic cancer sublines with different MUC4 expression for co-incubation system. By utilizing appropriate control to rule out the possible apoptosis-induced pathway of intrinsic activated cell-autonomous death (ACAD) and analogous antigen-dependent apoptosis of CTL (ADAC) in our study system, further analysis of the effect of MUC4 membrane-expression, supernatants and blockade of CTL surface Fas receptor on MS-CTL apoptosis was carried out. The results demonstrated that the level of MUC4 membrane expression strongly positively correlated with MS-CTL apoptosis and the influence of supernatants and Fas-blockade did not significantly correlate with MS-CTL apoptosis. This evidence suggested that there may be a novel counterattack pathway of pancreatic cancer cells, which is a MUC4-mediated, cell contact-dependent and Fas-independent process, to induce CTL apoptosis. Therefore, further exploration and understanding of the potential counterattack mechanisms is beneficial to enhance the efficacy of MUC4 specific tumor vaccines.

Altered expression of transmembrane mucins, MUC1 and MUC4, in bladder cancer: pathological implications in diagnosis

PURPOSE

Radical changes in both expression and glycosylation pattern of transmembrane mucins have been observed in various malignancies. We and others have shown that MUC1 and MUC4, two transmembrane mucins, play a sentinel role in cell signaling events that drive several epithelial malignancies. In the present study, we investigated the expression profile of MUC1 and MUC4 in the non-neoplastic bladder urothelium, in various malignant neoplasms of bladder and in bladder carcinoma cell lines.

MATERIAL AND METHODS

Immunohistochemistry was performed on tissue sections from the urinary bladder biopsies, resection samples and tissue microarrays (TMAs) with monoclonal antibodies specific for MUC1 and MUC4. We also investigated their expression in bladder carcinoma cell lines by RT-PCR and immunoblotting.

RESULTS

MUC1 is expressed on the apical surface or in umbrella cells of the normal non-neoplastic bladder urothelium. Strong expression of MUC1 was also observed in urothelial carcinoma (UC). MUC1 staining increased from normal urothelium (n = 27, 0.35±0.12) to urothelial carcinoma (UC, n = 323, H-score, 2.4±0.22, p≤0.0001). In contrast to MUC1, MUC4 was expressed in all the layers of non-neoplastic bladder urothelium (n = 14, 2.5±0.28), both in the cell membrane and cytoplasm. In comparison to non-neoplastic urothelium, the loss of MUC4 expression was observed during urothelial carcinoma (n = 211, 0.56±0.06). However, re-expression of MUC4 was observed in a subset of metastatic cases of urothelial carcinoma (mean H-score 0.734±0.9).

CONCLUSION

The expression of MUC1 is increased while that of MUC4 decreased in UC compared to the normal non-neoplastic urothelium. Expression of both MUC1 and MUC4, however, are significantly higher in urothelial carcinoma metastatic cases compared to localized UC. These results suggest differential expression of MUC1 and MUC4 during development and progression of bladder carcinoma.