MUC1 and metastatic cancer: expression, function and therapeutic targeting

A Multifunctional Platform for the Capture, Release, And Enumeration of Circulating Tumor Cells Based on Aptamer Binding, Nicking Endonuclease-Assisted Amplification, And Inductively Coupled Plasma Mass Spectrometry Detection

Inductively coupled plasma mass spectrometry (ICP-MS) combined with element tags has been well designed and extensively applied in cell enumeration. It possesses superior quantitative capability, strong resistance to matrix interference, multiplex detection capability but destructive characteristic. Herein, we constructed an ICP-MS based multifunctional platform for capture, nondestructive enumeration, and release of circulating tumor cells (CTCs). Aptamer on capture probe recognized Mucin 1 (MUC1) on membrane of MCF-7 cells specifically, thus the cells were captured by probe and the Initiator originally hybridized with Aptamer was substituted by MUC1 and released into solution. Then the released Initiator was separated from the captured cells and hybridized with Tb labeled Substrate on detection probe to release a large amount of nicked Tb fragments through the nicking endonuclease assisted amplification for subsequent ICP-MS detection. Meanwhile, cells captured by probe were released by nuclease digestion for further reculture. Such a strategy effectively avoids CTCs destruction resulted from ICP-MS enumeration, increases the detection sensitivity of ICP-MS by involving nicking endonuclease assisted amplification, and realizes cell recovery for further analysis. A limit of detection of 87 MCF-7 cells and a linear range of 250-10 000 MCF-7 cells were realized for ICP-MS enumeration. A cell recovery of 52.7% (with capture and release efficiency of 63.9 and 82.5%, respectively) and a viability of 74.3% were obtained, meanwhile the released cells exhibited strong proliferation ability. This multifunctional platform for CTCs capture, enumeration, and release has great applicable potential in early diagnosis and individual treatment for cancer.

Correlation between salivary and serum CA15-3 concentrations in patients with breast cancer

The early detection of breast cancer enables the use of less aggressive treatment and increases patient survival. The transmembrane glycoprotein mucin 1, which is also known as cancer antigen 15-3 (CA15-3), is aberrantly glycosylated and overexpressed in a variety of epithelial cancers, and serves a crucial role in the progression of the disease. CA15-3 is currently used as a marker of breast cancer. In the present study, CA15-3 concentrations in saliva and blood of patients with breast cancer were evaluated to test new assays to detect salivary CA15-3 in addition to ELISA and its diagnostic value. To the best of our knowledge, there are no previous reports of the use of chemiluminescence assay (CLIA) and electrochemiluminescence assay (ECLIA) in saliva. Saliva and blood were collected on the same day from patients with breast cancer (n=26) and healthy controls (n=28). For each subject, the level of serum CA15-3 was measured using ECLIA, and the level of salivary CA15-3 was measured using ECLIA, CLIA and enzyme-linked immunosorbent assay (ELISA). ELISA and CLIA were able to detect CA15-3 in saliva; however, ECLIA could not detect salivary CA15-3. There was no significant difference between the mean serum and salivary CA15-3 levels in patients with breast cancer or healthy controls. The levels of CA15-3 were highest for luminal breast cancer subtypes and stage IV cases. A moderate correlation was observed between salivary and serum CA15-3 levels as measured by ELISA in breast cancer patients (r=0.56; P=0.0047). The results demonstrated that ECLIA was not a good method to detect salivary CA15-3, although it is the gold standard for detecting serum CA15-3. The presence of CA15-3 in saliva was confirmed, and this will be useful in future research. Further investigations are necessary to confirm the ability to detect salivary CA15-3 and its correlation with serum CA15-3.

89Zr-Labeled AR20.5: A MUC1-Targeting ImmunoPET Probe

High expression levels of the tumor-associated antigen MUC1 have been correlated with tumor aggressiveness, poor response to therapy, and poor survival in several tumor types, including breast, pancreatic, and epithelial ovarian cancer. Herein, we report the synthesis, characterization, and in vivo evaluation of a novel radioimmunoconjugate for the immuno-positron emission tomography (immunoPET) imaging of MUC1 expression based on the AR20.5 antibody. To this end, we modified AR20.5 with the chelator desferrioxamine (DFO) and labeled it with the positron-emitting radiometal zirconium-89 (t_1/2 ~3.3 d) to produce [⁸⁹Zr]Zr-DFO-AR20.5. In subsequent in vivo experiments in athymic nude mice bearing subcutaneous MUC1-expressing ovarian cancer xenografts, [⁸⁹Zr]Zr-DFO-AR20.5 clearly delineated tumor tissue, producing a tumoral activity concentration of 19.1 ± 6.4 percent injected dose per gram (%ID/g) at 120 h post-injection and a tumor-to-muscle activity concentration ratio of 42.4 ± 10.6 at the same time point. Additional PET imaging experiments in mice bearing orthotopic MUC1-expressing ovarian cancer xenografts likewise demonstrated that [⁸⁹Zr]Zr-DFO-AR20.5 enables the visualization of tumor tissue-including metastatic lesions-with promising tumor-to-background contrast.

MUC1 contributes to goblet cell metaplasia and MUC5AC expression in response to cigarette smoke in vivo

Goblet cell metaplasia (GCM) and mucin overproduction are a hallmark of chronic rhinosinusitis (CRS) and chronic obstructive pulmonary disease (COPD). In the airways, cigarette smoke (CS) induces activation of the epidermal growth factor receptor (EGFR) leading to GCM and overexpression of the gel-forming mucin MUC5AC. Although previous studies have demonstrated that a membrane-bound mucin, MUC1, modulates the activation of CS-induced EGFR, the role of MUC1 in CS-induced GCM and mucin overproduction has not been explored. In response to CS exposure, wild-type (WT) rats displayed Muc1 translocation from the apical surface of airway epithelium to the intracellular compartment of hyperplastic intermediate cells, EGFR phosphorylation, GCM, and Muc5ac overproduction. Similarly, human CRS sinonasal tissues demonstrated hyperplasia of intermediate cells enriched with MUC1 in the intracellular compartment, which was accompanied by GCM and increased MUC5AC expression. To further evaluate the role of Muc1 in vivo, a Muc1 knockout (KO) rat (MUC in humans and Muc in animals) was developed. In contrast to WT littermates, Muc1-KO rats exhibited no activation of EGFR, and were protected from GCM and Muc5ac overproduction. Genetic knockdown of MUC1 in human lung or Muc1 knockout in primary rat airway epithelial cells led to significantly diminished EGF-induced MUC5AC production. Together, these findings suggest that MUC1-dependent EGFR activation mediates CS-induced GCM and mucin overproduction. Strategies designed to suppress MUC1-dependent EGFR activation may provide a novel therapeutic approach for treating mucin hypersecretion in CRS and COPD.

Lipid rafts as signaling hubs in cancer cell survival/death and invasion: implications in tumor progression and therapy: Thematic Review Series: Biology of Lipid Rafts

Cholesterol/sphingolipid-rich membrane domains, known as lipid rafts or membrane rafts, play a critical role in the compartmentalization of signaling pathways. Physical segregation of proteins in lipid rafts may modulate the accessibility of proteins to regulatory or effector molecules. Thus, lipid rafts serve as sorting platforms and hubs for signal transduction proteins. Cancer cells contain higher levels of intracellular cholesterol and lipid rafts than their normal non-tumorigenic counterparts. Many signal transduction processes involved in cancer development (insulin-like growth factor system and phosphatidylinositol 3-kinase-AKT) and metastasis [cluster of differentiation (CD)44] are dependent on or modulated by lipid rafts. Additional proteins playing an important role in several malignant cancers (e.g., transmembrane glycoprotein mucin 1) are also being detected in association with lipid rafts, suggesting a major role of lipid rafts in tumor progression. Conversely, lipid rafts also serve as scaffolds for the recruitment and clustering of Fas/CD95 death receptors and downstream signaling molecules leading to cell death-promoting raft platforms. The partition of death receptors and downstream signaling molecules in aggregated lipid rafts has led to the formation of the so-called cluster of apoptotic signaling molecule-enriched rafts, or CASMER, which leads to apoptosis amplification and can be pharmacologically modulated. These death-promoting rafts can be viewed as a linchpin from which apoptotic signals are launched. In this review, we discuss the involvement of lipid rafts in major signaling processes in cancer cells, including cell survival, cell death, and metastasis, and we consider the potential of lipid raft modulation as a promising target in cancer therapy.

Recurrence After Resection for Intraductal Papillary Neoplasm of Bile Duct (IPNB) According to Tumor Location

BACKGROUND

No studies have yet analyzed the characteristics of recurrence after resection for intraductal papillary neoplasm of bile duct (IPNB) based on tumor location. We analyzed the patterns, timing, and risk factors for recurrence.

METHODS

From 1994 to 2014, data from 103 patients who were diagnosed with IPNB were retrospectively reviewed. Among these, 44 were extrahepatic IPNB (E-IPNB) and 59 were intrahepatic IPNB (I-IPNB).

RESULTS

CK20, pancreaticobiliary type, tumor invasion beyond ductal wall, tumor invasion to adjacent organs, and invasive disease were more frequently found in E-IPNB than in I-IPNB (22.7 vs. 8.5%; p = 0.043, 38.6 vs. 23.7%; p = 0.050, 20.5 vs. 11.9%; p < 0.001, 4.5 vs. 1.7%; p < 0.001 and 93.2 vs. 55.9%; p < 0.001). E-IPNB has poorer 5-year recurrence-free survival (RFS) compared to I-IPNB (51.7 vs. 91.4%; p < 0.001). There was no significant difference in the rate of initial isolated locoregional recurrence and initial distant recurrence according to tumor location (14.6 in E-IPNB vs. 3.0% in I-IPNB; p = 0.123, 19.5 in E = IPNB vs. 12.0% in I-IPNB; p = 0.136). Recurrence rate according to timing was different between E-IPNB and I-IPNB: within 1 year (33.3% vs. 83.3%; p = 0.061) and 1-3 years (50.0% vs. 0%; p = 0.052). The independent prognostic factors for RFS were tumor location (p = 0.034) and lymph node metastasis (p = 0.013).

CONCLUSIONS

E-IPNB has a worse prognosis than I-IPNB. Different follow-up schedules for surveillance according to tumor location are needed after surgery.

In vivo anti-MUC1+ tumor activity and sequences of high-affinity anti-MUC1-SEA antibodies

Cleavage of the MUC1 glycoprotein yields two subunits, an extracellular alpha-subunit bound to a smaller transmembrane beta-subunit. Monoclonal antibodies (mAbs) directed against the MUC1 alpha-beta junction comprising the SEA domain, a stable cell-surface moiety, were generated. Sequencing of all seven anti-SEA domain mAbs showed that they clustered into four groups and sequences of all groups are presented here. mAb DMB5F3 with picomolar affinity for the MUC1 SEA target was selected for further evaluation. Immunohistochemical staining of a series of malignancies with DMB5F3 including lung, prostate, breast, colon, and pancreatic carcinomas revealed qualitative and qualitative differences between MUC1 expression on normal versus malignant cells: DMB5F3 strongly stained malignant cells in a near-circumferential pattern, whereas MUC1 in normal pancreatic and breast tissue showed only weak apical positivity of ductal/acinar cells. Humanized chimeric DMB5F3 linked to ZZ-PE38 (ZZ IgG-binding protein fused to Pseudomonas exotoxin) induced vigorous cytotoxicity of MUC1⁺ malignant cells in vitro. The intensity of cell killing correlated with the level of MUC1 expression by the target cell, suggesting a MUC1 expression threshold for cell killing. MUC1⁺ Colo357 pancreatic cancer cells xenotransplanted into nude and SCID mice models were treated with the chDMB5F3:ZZ-PE38 immunocomplex. In both transplant models, chDMB5F3:ZZ-PE38 exhibited significant in vivo anti-tumor activity, suppressing up to 90% of tumor volume in the SCID model compared with concomitant controls. The efficacy of chDMB5F3:ZZ-PE38 immunotoxin in mediating tumor killing both in vitro and in vivo strongly suggests a clinical role for anti-MUC1 SEA antibody in the treatment of MUC1-expressing malignancies.

Breast cancer cutaneous metastases are associated to uMUC1 and sialyl Lewis x and to highly malignant primary tumors

Breast cancer spreading to different organs have been related to different molecules and mechanisms, but cutaneous metastasis remains unexplored. Increasing evidence showed that MUC1 and some of its carbohydrate associated antigens may be implicated in breast cancer metastasis. In this study we analyzed these tumor markers in order to identify breast cancer cutaneous metastatic profiles. A cohort of 26 primary tumors from breast cancer patients with cutaneous metastases were included; also, cutaneous and lymphatic node metastatic samples and primary tumors from breast cancer patients without metastases were analysed. Immunohistochemical (IHC) studies demonstrated that both underglycosylated MUC1 (uMUC1) and sialyl Lewis x (sLex) to be positively associated with cutaneous metastatic primary tumors (p < 0.05). Notably, a high percentage of tumors with cutaneous metastases were characterized as triple negative and Her2+ tumors (37.5 % and 29 %, respectively). Some discordant results were found between primary tumors and their matched cutaneous metastases. To determine if MUC1 variants may be carriers of carbohydrate antigens, subcellular fractions from a cutaneous metastatic lesion were obtained, immunoprecipitated and analyzed by Western blot. We found that the isolated uMUC1 with a molecular weight of>200 kDa was also the site for binding of anti-sLex MAb; in coincidence, a high correlation of positive IHC expression of both markers was observed. Our findings confirm that breast cancer cutaneous metastases were associated to highly malignant primary tumors and sustain the hypothesis that u-MUC1 and sLe x may drive breast cancer cutaneous metastases.

Insights into brain metastasis: Recent advances in circulating tumor cell research

Background

How tumor cells disseminate to brain and establish brain metastasis remains partly an unsolved problem. This devastating complication of many cancers is initiated by a rare subset of the circulating tumor cells (CTCs) shed into the blood stream. Thus, the profiling of the molecular properties in these brain metastasis‐initiating CTCs is essential to uncover the mechanisms underlying brain metastasis.

Recent Findings

Important efforts to improve the enrichment and detection of CTCs enabled the detailed molecular and functional analysis of CTCs that drive brain metastasis. In this review, we highlight key findings on existing preclinical studies that provide insights toward a comprehensive picture of brain metastasis‐precursors in CTCs and the potential clinical implications.

Conclusion

A deeper understanding of the brain metastasis precursors should help to stratify high‐risk patients and improve preventive therapeutic strategies. Although all these preclinical evidences have yet to be translated into patients, they provide considerable hope to benefit patients with brain metastases in the future.

A double safety lock tumor-specific device for suicide gene therapy in breast cancer

The complexity and continuous evolution of cancer make the design of novel strategies of treatment a constant challenge in biomedicine. Moreover, most of cancer treatments are still not tumor-specific and provoke high systemic toxicity. Herein we have developed a novel selective nanodevice to eliminate tumor cells while leaving healthy ones intact. To achieve this objective, a polyplex carrier, comprising an elastin like-recombinamer covalently conjugated to an aptamer and complexed with therapeutic DNA, was tested. This carrier forms a double-lock multifunctional device due to specific binding to a tumor cell marker and the selective expression of therapeutic DNA inside human breast-cancer cells. Due to the stability provided by ELRs, the homogeneous population of polyplexes obtained showed selective toxicity against cancer cells in in vitro and in vivo assay. Inhibition of tumor progression was detected early being very significant at the end point, with a dose-dependent reduction in tumor mass. Histological studies revealed a specific reduction in tumor parenchyma and in specific tumor cell markers. These results represent an important step toward the rational development of an efficient, safe and more specialized gene-delivery device for tumor therapy.

In Silico Design of Novel Mutant Anti-MUC1 Aptamers for Targeted Cancer Therapy

The transmembrane glycoprotein mucin 1 (MUC1) is an attractive tumor marker for cancer therapy and diagnosis. The nine amino acid extracellular epitope APDTRPAPG of this protein is selectively recognized by the S2.2 single-stranded DNA anti-MUC1 aptamer, which has emerged as a promising template for designing novel targeting agents for MUC1-directed therapy. In this work, 100 ns molecular dynamics (MD) simulations, MM/GBSA binding free energy calculations, and conformational analysis were employed to propose a novel prospective anti-MUC1 aptamer with increased affinity toward the MUC1 epitope resulting from the double mutation of the T11 and T12 residues with PSU and U nucleosides, respectively. The double mutant aptamer exhibits a tight interaction with the MUC1 epitope and adopts a groove conformation that structurally favors the intermolecular contact with the epitope through the intermediate T11-A18 region leaving the 3' and 5' ends free for further chemical conjugation with a nanocarrier or pharmaceutical. These results are valuable to gain understanding about the molecular features governing aptamer-epitope interactions and constitute a first key step for the design of novel aptamer-based nanocarriers for MUC1-targeted cancer therapy.

MUC1 gene silencing inhibits proliferation, invasion, and migration while promoting apoptosis of oral squamous cell carcinoma cells

The aim of the present study is to investigate the role of RNA interference in the inhibition of MUC1 gene expression in occurrence and metastasis of oral squamous cell carcinoma (OSCC) and its in-depth mechanisms. The OSCC and normal oral mucosa tissues, as well as normal oral epithelial cell line HOK and OSCC cell line SCC-4, Cal-27, TSCCA, Tca8113 were obtained to detect the expression of MUC1. Slug expression in OSCC and normal oral mucosa tissues was also determined. The OSCC cells were grouped to investigate the role of MUC1 gene silencing on proliferation, DNA replication, cell cycle distribution, apoptosis, colony formation ability, epithelial-mesenchymal transition (EMT), invasion, and migration of OSCC cells. We first found higher positive rate of MUC1 and Slug expression in OSCC tissues. Next, it was determined that higher expression of MUC1 was found in OSCC tissues and cells. Furthermore, silencing of MUC1 declined Slug expression, inhibited the proliferation, DNA replication, cell cycle progression, and EMT while inducing apoptosis of OSCC cells. Our study suggests that overexpression of MUC1 is found in OSCC, and MUC1 gene silencing could inhibit the proliferation, invasion, and migration while inducing apoptosis of OSCC cells.

The "nano to micro" transition of hydrophobic curcumin crystals leading to in situ adjuvant depots for Au-liposome nanoparticle mediated enhanced photothermal therapy

Photothermal therapy (PTT) is emerging as a promising treatment for skin cancer. Plasmon-resonant gold-coated liposome nanoparticles (Au Lipos NPs) specifically absorb Near Infra-Red (NIR) light resulting in localized hyperthermia (PTT). In the current study, curcumin (a hydrophobic anticancer agent) was entrapped in Au Lipos NPs as nanocrystals to act as an adjuvant for the PTT of melanoma. NIR light irradiation on Au Lipos Cur NPs triggered the release of curcumin nanocrystals which coalesce to form curcumin microcrystals (CMCs). An in situ"nano to micro" transition in the crystal state of curcumin was observed. This in situ transition leads to the formation of CMCs. These CMCs exhibited sustained release of curcumin for a prolonged duration (>10 days). The localized availability of curcumin aids in enhancing PTT by inhibiting the growth and mobility of cancer cells that escape PTT. In the in vitro modified scratch assay, the Au Lipos Cur NP + Laser group showed >1.5 fold enhanced therapeutic coverage when compared with the Au Lipos NP + Laser group. In vivo PTT studies performed in a B16 tumor model using Au Lipos Cur NPs showed a significant reduction of the tumor volume along with the localized release of curcumin in the tumor environment. It was observed that the localized release of curcumin enables an immediate adjuvant effect resulting in the enhancement of PTT.

Outcome Determining Factors of Intraductal Papillary Neoplasm of the Biliary Tract (IPNB)-a Single Center Survey and Analysis of Current Literature

PURPOSE

Intraductal papillary neoplasms of the biliary tract (IPNB) are rare tumors originating from the bile duct epithelium. Metastatic disease of IPNB is extremely rare and only reported in a small number of cases worldwide. Due to this limitation in number, the treatment of IPNB mainly relies on retrospective case series.

PATIENTS AND METHODS

We reported three cases of IPNB, one benign, one carcinoma with lymph node metastasis, and one case with histologically proven metachronous pulmonary metastasis. We correlated our findings with the existing data found in the literature. All patients underwent hemihepatectomy and complete tumor resection was achieved.

RESULTS

Diagnosis of IPNB can be challenging due to varying presentation. The treatment of choice is surgical oncological resection in an early tumor stage. Long-term outcome highly depends on the underlying grade of dysplasia, multiplicity, and tumor-free margins. Aggressive tumor invasion is reported in up to 72% of cases in IPNB. Furthermore, the recurrence rate of IPNB is high with up to 22%. Further factors associated with an impaired survival are incomplete resection, lymph node involvement, and MUC1 expression.

CONCLUSION

High potential for dysplasia and proof of invasive carcinoma upon diagnosis are hallmarks of IPNB. Metastatic disease in IPNB is reported only in small numbers. IPNB is an aggressive tumor entity with impaired long-term outcomes. A drawback for interpretation of current data is the fact that they rely on case series and reports and are not validated through more powerful randomized multicentric trials.

Strobilanthes crispus inhibits migration, invasion and metastasis in breast cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Strobilanthes crispus (L.) Blume, locally known in Malaysia as "Pecah kaca" or "Jin batu", has been traditionally used for treatment of various ailments including cancer. We previously demonstrated that a standardized bioactive subfraction of S. crispus, termed as F3, possessed potent anticancer effects in both in vitro and in vivo breast cancer models.

AIM OF THE STUDY

To investigate the potential of F3 from S. crispus to prevent metastasis in breast cancer.

MATERIALS AND METHODS

The antimetastatic effects of F3 were first investigated on murine 4T1 and human MDA-MB-231 breast cancer cell (BCC) lines using cell proliferation, wound healing and invasion assays. A 4T1-induced mouse mammary carcinoma model was then used to determine the expression of metastasis tumor markers, epithelial (E)-cadherin, matrix metalloproteinase (MMP)-9, mucin (MUC)-1, nonepithelial (N)-cadherin, Twist, vascular endothelial growth factor (VEGF) and vimentin, using immunohistochemistry, following oral treatment with F3 for 30 days.

RESULTS

Significant growth arrest was observed with F3 IC₅₀ values of 84.27 µg/ml (24 h) and 74.41 µg/ml (48 h) for MDA-MB-231, and 87.35 µg/ml (24 h) and 78.75 µg/ml (48 h) for 4T1 cells. F3 significantly inhibited migration of both BCC lines at 50 μg/ml for 24 h (p = 0.018 and p = 0.015, respectively). Similarly, significant inhibition of invasion was demonstrated in 4T1 (75 µg/ml, p = 0.016) and MDA-MB-231 (50 µg/ml, p = 0.040) cells compared to the untreated cultures. F3 treatment resulted in reduced tumor growth compared to untreated mice (p < 0.01) or mice treated with tamoxifen (p < 0.05). Statistical parameters (absolute count, proportion, intensity and overall scores) indicating upregulation of E-cadherin expression were statistically significant in F3-treated compared to the untreated tumor-bearing mice. Similarly, F3 significantly reduced the expression of MMP-9, MUC1, N-cadherin, Twist, VEGF and vimentin in comparison with the TM (p < 0.01) group CONCLUSIONS: Our findings suggest that F3 exerts anti-metastatic effects independent of its cytotoxic effects, and these are supported by the increased expression of E-cadherin concurrent with downregulation of MMP-9, MUC1, N-cadherin, Twist, VEGF and vimentin expression in breast cancer.

Prognostic and clinicopathological value of MUC1 expression in colorectal cancer: A meta-analysis

BACKGROUND

Accumulating evidence supports the overexpression of mucin 1 (MUC1) in colorectal cancer (CRC), but the value of elevated MUC1 expression remains controversial. Here, we evaluated the prognostic and clinicopathological value of MUC1 expression in CRC.

MATERIALS AND METHODS

The Web of Science, PubMed, Embase, Cochrane Library, and Wanfang databases, as well as the China Biology Medicine disc (CBMdisc) and China National Knowledge Infrastructure (CNKI) were searched for studies on MUC1 expression and prognosis of CRC through July 20, 2018. The pooled relative risks (RRs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated to evaluate the prognostic and clinicopathological value of MUC1 expression in CRC. The Revman version 5.3 package and STATA, version 12 were employed for pooled analysis and analysis of publication bias.

RESULTS

This meta-analysis included 16 published studies. The combined analysis showed that CRC patients with high MUC1 expression had a worse clinical outcome in overall survival (OS) (HR = 1.51, 95% CI = 1.30-1.75, P <.00001). In addition, high MUC1 expression was associated with higher TNM stage (RR = 1.44, 95% CI = 1.17-1.77, P = .0007), greater depth of invasion (RR = 1.30, 95% CI = 1.10-1.53, P = .002), and lymph node metastasis (RR = 1.47, 95% CI = 1.20-1.80, P = .0002) of CRC. However, the elevated MUC1 expression was not related to disease-free survival/recurrence-free survival (DFS/RFS) (HR = 1.51, 95% CI = 0.78-2.89, P = .22), histological grade (RR = 1.15, 95% CI = 0.96-1.38, P = .12), gender (RR = 0.95; 95% CI = 0.83-1.08, P = .44), tumor size (RR = 1.11, 95% CI = 0.85-1.44, P = .44), tumor site (RR = 1.01, 95% CI = 0.88-1.16, P = .84), or mucinous component (RR = 0.83, 95% CI = 0.60-1.14, P = .24) in CRC.

CONCLUSION

Our findings indicated that high MUC1 expression represents a marker of poor prognosis in CRC. Meanwhile, elevated MUC1 expression was associated with advanced TNM stage, greater depth of invasion, and lymph node metastasis.

Resolving gastric cancer aetiology: an update in genetic predisposition

Every year gastric cancer accounts for nearly 1 million new cases and more than 720 000 deaths worldwide. Prognosis is dismal because most patients are diagnosed with advanced disease; as such, gastric cancer outcomes will benefit from better methods for identification of at-risk individuals that can be targeted for early detection. One approach to targeting high-risk populations is to identify individuals who are genetically predisposed to gastric cancer, as up to 15% of all patients report family history of the disease. On the basis of clinical manifestations, three gastric cancer syndromes have been described, but the diagnosis of some of these syndromes is suboptimal and could benefit from genetic information. Over the past decade, genome-wide association and next-generation sequencing studies have identified several low penetrance variants and high-risk genes, considerably increasing our understanding of inherited gastric cancer predisposition. From these studies, PALB2 has emerged as a new familial gastric cancer gene. Furthermore, genetic analyses in patients with sporadic gastric cancer suggest that more than 10% of all cases have pathogenic mutations, a finding of great importance for cancer aetiology. In this Review, we summarise the role of genetics in gastric cancer aetiology and the implications of genetics findings for the prevention of this malignancy.

Regulatory mechanisms of miR-145 expression and the importance of its function in cancer metastasis

MicroRNAs are post-transcriptional mediators of gene expression and regulation, which play influential roles in tumorigenesis and cancer metastasis. The expression of tumor suppressor miR-145 is reduced in various cancer cell lines, containing both solid tumors and blood malignancies. However, the responsible mechanisms of its down-regulation are a complicated network. miR-145 is potentially able to inhbit tumor cell metastasis by targeting of multiple oncogenes, including MUC1, FSCN1, Vimentin, Cadherin, Fibronectin, Metadherin, GOLM1, ARF6, SMAD3, MMP11, Snail1, ZEB1/2, HIF-1α and Rock-1. This distinctive role of miR-145 in the regulation of metastasis-related gene expression may introduce miR-145 as an ideal candidate for controlling of cancer metastasis by miRNA replacement therapy. The present review aims to discuss the current understanding of the different aspects of molecular mechanisms of miR-145 regulation as well as its role in r metastasis regulation.

Rosmarinic acid influences collagen, MMPs, TIMPs, glycosylation and MUC1 in CRL-1739 gastric cancer cell line

Rosmarinic acid (RA) is a natural phenylpropanoid with numerous pharmacological activities. Because of limited studies of the effects of RA action in gastric cancer cells we examined how 100 and 200 μM acid influences MMPs, TIMPs, collagen, MUC1 and specific sugar antigens in gastric adenocarcinoma CRL-1739 cells. We revealed inhibitory effect of RA on MMP-9 activity what was correlated with increased collagen type I expression, main ECM substrate degraded by MMPs. Tissue inhibitor of MMPs, TIMP-1 but not TIMP-2 was significantly decreased on the protein level and increased on mRNA level by RA action what can suggest TIMP-1 independent inhibitory action of an acid on MMP-9 activity. Glycosylation of gastric cancer proteins was also effected by RA. ELISA tests revealed inhibitory effect of an acid on Tn antigen in cell lysates and culture supernatant and on T antigen in cell lysates. RA inhibited also sialylated Tn antigen in protein of culture supernatant and sialyl T in cell lysates. Extracellular domain of MUC1 mucin, main carrier of Tn and T antigens was significantly inhibited by higher dose of RA. The data suggest potential usefulness of RA as a complementary agent supporting chemotherapy in cancer treatment.

Multiplexed Autoantibody Signature for Serological Detection of Canine Mammary Tumours

Spontaneously occurring canine mammary tumours (CMTs) are the most common neoplasms of female unspayed dogs and are of potential importance as models for human breast cancer as well. Mortality rates are thrice higher in dogs as compared to humans with breast cancer, which can partly be attributed to lack of diagnostic techniques for their early detection. Human breast cancer studies reveal role of autoantibodies in early cancer diagnosis and also the usefulness of autoantibody panels in increasing the sensitivity, as well as, specificity of diagnostic assays. Therefore, in this study, we took advantage of high-throughput Luminex technique for developing a multiplex assay to detect autoantibody signatures against 5 canine mammary tumour-associated autoantigens (TAAs). These TAAs were expressed separately as fusion proteins with halo tag at the N-terminus, which allows easy and specific covalent coupling with magnetic microspheres. The multiplex assay, comprising a panel of candidate autoantigens (TPI, PGAM1, MNSOD, CMYC & MUC1) was used for screening circulating autoantibodies in 125 dog sera samples, including 75 mammary tumour sera and 50 healthy dog sera. The area under curve (AUC) of the combined panel of biomarkers is 0.931 (p < 0.0001), which validates the discriminative potential of the panel in differentiating tumour patients from healthy controls. The assay could be conducted in 3hrs using only 1ul of serum sample and could detect clinical cases of canine mammary tumour with sensitivity and specificity of 78.6% and 90%, respectively. In this study, we report for the first time a multiplexed assay for detection of autoantibodies in canine tumours, utilizing luminex technology and halo-tag coupling strategy. Further to the best of our knowledge, autoantibodies to CMYC and MUC1 have been reported for the first time in canines in this study.

RNA sequencing (RNA-Seq) and its application in ovarian cancer

Despite the surgical and chemotherapeutic advances over the past few decades, ovarian cancer remains the leading cause of gynecological cancer-related mortality. The absence of biomarkers in early detection and the development of drug resistance are principal causes of treatment failure in ovarian cancer. Recent progress in RNA sequencing (RNA-Seq) with Next Generation Sequencing technology has expanded the understanding of the molecular pathogenesis of ovarian cancer. As compared to previous hybridization-based microarray and Sanger sequence-based methods, RNA-Seq provides multiple layers of resolutions and transcriptome complexity, with less background noise and a broader dynamic range of RNA expression. Beyond quantifying gene expression, the data generated by RNA-Seq accelerates the identification of alternatively spliced genes, fusion genes, mutations/SNPs, allele-specific expression, novel transcripts and non-coding RNAs. RNA-Seq has been successfully applied in ovarian cancer research for earlier detection, ascertaining pathological origin, and defining the aberrant genes and dysregulated molecular pathways across patient groups. This review outlines the distinct advantages of RNA-Seq compared to other transcriptomics methods and its recent applications in ovarian cancer.

A tension-mediated glycocalyx-integrin feedback loop promotes mesenchymal-like glioblastoma

Glioblastoma multiforme (GBMs) are recurrent lethal brain tumours. Recurrent GBMs often exhibit mesenchymal, stem-like phenotypes that could explain their resistance to therapy. Analyses revealed that recurrent GBMs have increased tension and express high levels of glycoproteins that increase the bulkiness of the glycocalyx. Studies showed that a bulky glycocalyx potentiates integrin mechanosignalling and tissue tension and promotes a mesenchymal, stem-like phenotype in GBMs. Gain- and loss-of-function studies implicated integrin mechanosignalling as an inducer of GBM growth, survival, invasion and treatment resistance, and a mesenchymal, stem-like phenotype. Mesenchymal-like GBMs were highly contractile and expressed elevated levels of glycoproteins that expanded their glycocalyx, and they were surrounded by a stiff extracellular matrix that potentiated integrin mechanosignalling. Our findings suggest that there is a dynamic and reciprocal link between integrin mechanosignalling and a bulky glycocalyx, implying a causal link towards a mesenchymal, stem-like phenotype in GBMs. Strategies to ameliorate GBM tissue tension offer a therapeutic approach to reduce mortality due to GBM.

Enhancement of anti-tumor effect of plasmid DNA-carrying MUC1 by the adjuvanticity of FLT3L in mouse model

AIM

DNA vaccines have emerged as a promising strategy for cancer immunotherapy; however, their immunogenicity is weak. Fms-like tyrosine kinase 3-ligand (Flt3L) has been exploited for its ability to increase the proliferation of dendritic cells (DCs). The aim of the present study was to investigate whether co-administration of an adjuvant plasmid expressing mouse Flt3L and a DNA vaccine of the Mucin 1 (MUC1) antigen enhances immune responses.

METHODS

The recombinant plasmids pVAX1-MUC1 and pVAX1-Flt3L were constructed and injected into mice intramuscularly (i.m.), followed by electroporation. The humoral and cellular immune responses after immunization were examined by enzyme linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT), respectively. To evaluate the anti-tumor efficacy of the plasmids, a mouse model of MUC1-expressing tumors was established.

RESULTS

The results showed that co-administration of an adjuvant plasmid and a DNA vaccine stimulated the production of higher titers of specific antibodies and a T cell response and suppressed the growth of subcutaneous tumors expressing MUC1. Collectively, our results indicate that a plasmid expressing murine Flt3L could stimulate stronger immune responses.

CONCLUSION

These observations emphasize the potential of Flt3L as an adjuvant for colon cancer DNA vaccines.

Diffuse Bone Marrow Metastasis as the Initial Presentation of an Occult Breast Cancer

Introduction

Breast cancer is one of the malignancies which tend to involve the bone marrow, but initial presentation with diffuse bone marrow metastasis from an occult breast cancer is very rare. Prognosis is generally very poor for marrow metastasis from solid tumors except that breast cancer is a treatable disease even in such a dismal condition.

Case

A 64-year-old woman's headache was found to result from diffuse adenocarcinoma metastasis in the bone marrow from an unknown primary site. Intensive immunohistochemistry study of bone marrow biopsy specimen confirmed the disease nature to be an estrogen receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Mammography and magnetic resonance imaging of breasts revealed a suspicious primary lesion in the right breast. Treatment with tamoxifen alone achieved a sustained response.

Discussion

Mucin 1 (MUC1), also known as cancer antigen 15-3 (CA 15-3), facilitates motility and metastatic potential of breast cancer cells. Interleukin-1β (IL-1β) drives breast cancer cell growth and colonization in bone marrow adipose tissue niche. Receptor activator of nuclear factor kappa-B (RANK) and its ligand (RANKL) activate osteoclasts to make a favorable bone marrow microenvironment for tumor cells. Agents against MUC1, IL-1β, and RANKL might be of therapeutic effect for patients like ours.

CAR T cell therapy for breast cancer: harnessing the tumor milieu to drive T cell activation

BACKGROUND

The adoptive transfer of T cells redirected to tumor via chimeric antigen receptors (CARs) has produced clinical benefits for the treatment of hematologic diseases. To extend this approach to breast cancer, we generated CAR T cells directed against mucin1 (MUC1), an aberrantly glycosylated neoantigen that is overexpressed by malignant cells and whose expression has been correlated with poor prognosis. Furthermore, to protect our tumor-targeted cells from the elevated levels of immune-inhibitory cytokines present in the tumor milieu, we co-expressed an inverted cytokine receptor linking the IL4 receptor exodomain with the IL7 receptor endodomain (4/7ICR) in order to transform the suppressive IL4 signal into one that would enhance the anti-tumor effects of our CAR T cells at the tumor site.

METHODS

First (1G - CD3ζ) and second generation (2G - 41BB.CD3ζ) MUC1-specific CARs were constructed using the HMFG2 scFv. Following retroviral transduction transgenic expression of the CAR±ICR was assessed by flow cytometry. In vitro CAR/ICR T cell function was measured by assessing cell proliferation and short- and long-term cytotoxic activity using MUC1+ MDA MB 468 cells as targets. In vivo anti-tumor activity was assessed using IL4-producing MDA MB 468 tumor-bearing mice using calipers to assess tumor volume and bioluminescence imaging to track T cells.

RESULTS

In the IL4-rich tumor milieu, 1G CAR.MUC1 T cells failed to expand or kill MUC1+ tumors and while co-expression of the 4/7ICR promoted T cell expansion, in the absence of co-stimulatory signals the outgrowing cells exhibited an exhausted phenotype characterized by PD-1 and TIM3 upregulation and failed to control tumor growth. However, by co-expressing 2G CAR.MUC1 (signal 1 - activation + signal 2 - co-stimulation) and 4/7ICR (signal 3 - cytokine), transgenic T cells selectively expanded at the tumor site and produced potent and durable tumor control in vitro and in vivo.

CONCLUSIONS

Our findings demonstrate the feasibility of targeting breast cancer using transgenic T cells equipped to thrive in the suppressive tumor milieu and highlight the importance of providing transgenic T cells with signals that recapitulate physiologic TCR signaling - [activation (signal 1), co-stimulation (signal 2) and cytokine support (signal 3)] - to promote in vivo persistence and memory formation.

Perspective on Cancer Therapeutics Utilizing Analysis of Circulating Tumor Cells

Various methods are available for cancer screening, and the methods are performed depending on the origin site of cancer. Among these methods, biopsy followed by medical imaging is the most common. After cancer progression is determined, an optimal treatment—such as surgery, chemotherapy, and/or radiation therapy—is selected. A new assay has been developed that detects circulating tumor cells (CTCs). Tracking changes in CTCs may reveal important tumoral sensitivity information or resistance patterns to specific regimens and prompt changes in therapy on a personalized basis. Characterization of CTCs at the DNA, RNA, and protein levels is important for gaining insight for clinical applications. A small number of CTCs can be analyzed to obtain genome information such as the progression of cancer including metastasis, even in a single cluster. Although many clinical studies, particularly CTC enumeration and detection of specific oncogene expression, have increased the success rate of diagnosis and predicting prognosis, there is no consensus regarding the technical approaches and various aspects of the methodology, making it difficult to standardize optimal methods for CTC analysis. However, ongoing technological advances are currently being achieved and large-scale clinical studies are being conducted. Applying CTC analysis in the clinic would be very useful for advancing diagnosis, prognosis prediction, and therapeutics.

Perspective on Cancer Therapeutics Utilizing Analysis of Circulating Tumor Cells

Various methods are available for cancer screening, and the methods are performed depending on the origin site of cancer. Among these methods, biopsy followed by medical imaging is the most common. After cancer progression is determined, an optimal treatment-such as surgery, chemotherapy, and/or radiation therapy-is selected. A new assay has been developed that detects circulating tumor cells (CTCs). Tracking changes in CTCs may reveal important tumoral sensitivity information or resistance patterns to specific regimens and prompt changes in therapy on a personalized basis. Characterization of CTCs at the DNA, RNA, and protein levels is important for gaining insight for clinical applications. A small number of CTCs can be analyzed to obtain genome information such as the progression of cancer including metastasis, even in a single cluster. Although many clinical studies, particularly CTC enumeration and detection of specific oncogene expression, have increased the success rate of diagnosis and predicting prognosis, there is no consensus regarding the technical approaches and various aspects of the methodology, making it difficult to standardize optimal methods for CTC analysis. However, ongoing technological advances are currently being achieved and large-scale clinical studies are being conducted. Applying CTC analysis in the clinic would be very useful for advancing diagnosis, prognosis prediction, and therapeutics.

Synthetic MUC1 Antitumor Vaccine with Incorporated 2,3-Sialyl-T Carbohydrate Antigen Inducing Strong Immune Responses with Isotype Specificity

The endothelial glycoprotein MUC1 is known to underlie alterations in cancer by means of aberrant glycosylation accompanied by changes in morphology. The heavily shortened glycans induce a collapse of the peptide backbone and enable accessibility of the latter to immune cells, rendering it a tumor-associated antigen. Synthetic vaccines based on MUC1 tandem repeat motifs, comprising tumor-associated 2,3-sialyl-T antigen, conjugated to the immunostimulating tetanus toxoid, are reported herein. Immunization with these vaccines in a simple water/oil emulsion produced a strong immune response in mice to which stimulation with complete Freund's adjuvant (CFA) was not superior. In both cases, high levels of IgG1 and IgG2a/b were induced in C57BL/6 mice. Additional glycosylation in the immunodominant PDTRP domain led to improved binding of the induced antisera to MCF-7 breast tumor cells, compared with that of the monoglycosylated peptide vaccine.

Simultaneous isolation and detection of single breast cancer cells using surface-enhanced Raman spectroscopy

Nowadays, cancer is one of the most dangerous and deadly disease all around the world. Cancer that is diagnosed at early stages is more likely to be treated successfully. Treatment of progressed cancer is very difficult, and generally surviving rates are much lower. Therefore, much research has been focused on developing non-invasive methods for detection of cancer and monitoring of its progress. Within this contribution, we present a novel strategy for selective isolation and detection of breast cancer cell lines (MCF-7 and BT-20) based on surface enhanced Raman scattering (SERS). A simplified protocol based on cell-aptamer interaction has been developed in which core-shell (Au@Fe₃O₄) nanoparticles (CSNs) were functionalized with a mucin 1 (MUC1) specific aptamer (Apt1) to capture cells through the interaction between Apt1 and overexpressed protein (MUC1) on the surface of the tumor cells. Meanwhile, a SERS nano-tag, synthesized by the conjugation of Apt1 to the surface of BSA coated and with 4-mercaptopyridine (4-Mpy) functionalized gold nanoparticles, was used to detect the isolated cells. As a conclusion, the proposed strategy can be extended to isolate and detect cells more precisely based on the detection of different kinds of biomarkers on the surface of cancer cells, simultaneously.

Inhibition of MUC1 biosynthesis via threonyl-tRNA synthetase suppresses pancreatic cancer cell migration

Mucin1 (MUC1), a heterodimeric oncoprotein, containing tandem repeat structures with a high proportion of threonine, is aberrantly overexpressed in many human cancers including pancreatic cancer. Since the overall survival rate of pancreatic cancer patients has remained low for several decades, novel therapeutic approaches are highly needed. Intestinal mucin has been known to be affected by dietary threonine supply since de novo synthesis of mucin proteins is sensitive to luminal threonine concentration. However, it is unknown whether biosynthesis of MUC1 is regulated by threonine in human cancers. In this study, data provided suggests that threonine starvation reduces the level of MUC1 and inhibits the migration of MUC1-expressing pancreatic cancer cells. Interestingly, knockdown of threonyl-tRNA synthetase (TRS), an enzyme that catalyzes the ligation of threonine to its cognate tRNA, also suppresses MUC1 levels but not mRNA levels. The inhibitors of TRS decrease the level of MUC1 protein and prohibit the migration of MUC1-expressing pancreatic cancer cells. In addition, a positive correlation between TRS and MUC1 levels is observed in human pancreatic cancer cells. Concurrent with these results, the bioinformatics data indicate that co-expression of both TRS and MUC1 is correlated with the poor survival of pancreatic cancer patients. Taken together, these findings suggest a role for TRS in controlling MUC1-mediated cancer cell migration and provide insight into targeting TRS as a novel therapeutic approach to pancreatic cancer treatment.

A bulky glycocalyx fosters metastasis formation by promoting G1 cell cycle progression

Metastasis depends upon cancer cell growth and survival within the metastatic niche. Tumors which remodel their glycocalyces, by overexpressing bulky glycoproteins like mucins, exhibit a higher predisposition to metastasize, but the role of mucins in oncogenesis remains poorly understood. Here we report that a bulky glycocalyx promotes the expansion of disseminated tumor cells in vivo by fostering integrin adhesion assembly to permit G1 cell cycle progression. We engineered tumor cells to display glycocalyces of various thicknesses by coating them with synthetic mucin-mimetic glycopolymers. Cells adorned with longer glycopolymers showed increased metastatic potential, enhanced cell cycle progression, and greater levels of integrin-FAK mechanosignaling and Akt signaling in a syngeneic mouse model of metastasis. These effects were mirrored by expression of the ectodomain of cancer-associated mucin MUC1. These findings functionally link mucinous proteins with tumor aggression, and offer a new view of the cancer glycocalyx as a major driver of disease progression.

Mechanism of anticancer action of novel berenil complex of platinum(II) combined with anti-MUC1 in MCF-7 breast cancer cells

Mucin 1 (MUC1) is a high molecular weight transmembrane glycoprotein, that is overexpressed in >90% of breast cancers. It serves a crucial role in anti-apoptosis and tumor progression. MUC1 interacts with proteins in the extracellular matrix, at the cell membrane, in the cytoplasm and in the nucleus. The aim of the present study was to investigate the mechanism of anticancer action induced by novel berenil complex of platinum(II) (Pt12) together with a monoclonal antibody against MUC1 in breast cancer MCF-7 cells. The effect of combined treatment on the concentration of selected markers of apoptosis including proapoptotic B-cell lymphoma 2 associated X protein (Bax), caspase-8, cytochrome c and caspase-9, as well as selected proteins involved in intracellular signal transduction pathways including p53, phosphoinositide 3-kinase and phosphorylated protein kinase B (p-Akt) were analyzed. The results of the present study demonstrated that combined treatment may be a promising strategy in anticancer treatment and represents an alternative to monotherapy. All compounds used alone (Pt12, cisplatin and the anti-MUC1 antibody) increased the concentration of proapoptotic Bax, cytochrome c and caspase-9 in comparison with control, thus suggesting that they activated the mitochondrial apoptotic pathway. Pt12 alone significantly increased the concentration of caspase-8, which is responsible for the initiation of the extrinsic apoptotic pathway. However, the strongest effect was observed following Pt12 (20 µM) treatment combined with the anti-MUC1 antibody (10 µg/ml). These two compounds together strongly induced apoptosis in MCF-7 breast cancer cells via the external and internal apoptotic pathways. It was also demonstrated that combined treatment based on Pt12 and the anti-MUC1 antibody significantly reduced p-Akt concentration.

Circulating tumor cells: potential markers of minimal residual disease in ovarian cancer? a study of the OVCAD consortium

Purpose

In 75% of ovarian cancer patients the tumor mass is completely eradicated by established surgical and cytotoxic treatment; however, the majority of the tumors recur within 24 months. Here we investigated the role of circulating tumor cells (CTCs) indicating occult tumor load, which remains inaccessible by established diagnostics.

Experimental design

Blood was taken at diagnosis (baseline samples, n = 102) and six months after completion of adjuvant first-line chemotherapy (follow-up samples; n = 78). CTCs were enriched by density gradient centrifugation. A multi-marker immunostaining was established and further complemented by FISH on CTCs and tumor/metastasis tissues using probes for stem-cell like fusion genes MECOM and HHLA1.

Results

CTCs were observed in 26.5% baseline and 7.7% follow-up blood samples at a mean number of 12.4 and 2.8 CTCs per ml blood, respectively. Baseline CTCs indicated a higher risk of death in R0 patients with complete gross resection (univariate: HR 2.158, 95% CI 1.111–4.191, p = 0.023; multivariate: HR 2.720, 95% CI 1.340–5.522, p = 0.006). At follow-up, the presence of CTCs was associated with response to primary treatment as assessed using RECIST criteria. Chromosomal gains at MECOM and HHLA1 loci suggest that the observed cells were cancer cells and reflect pathophysiological decisive chromosomal aberrations of the primary and metastatic tumors.

Conclusions

Our data suggest that CTCs detected by the multi-marker protein panel and/or MECOM/HHLA1 FISH represent minimal residual disease in optimally debulked ovarian cancer patients. The role of CTCs cells especially for clinical therapy stratification of the patients has to be validated in consecutive larger studies applying standardized treatment schemes.

Role of C-Jun N-terminal Kinase in Hepatocellular Carcinoma Development

Hepatocellular carcinoma (HCC) is among the most frequently occurring cancers and the leading causes of cancer mortality worldwide. Identification of the signaling pathways regulating liver carcinogenesis is critical for developing novel chemoprevention and targeted therapies. C-Jun N-terminal kinase (JNK) is a member of a larger group of serine/threonine (Ser/Thr) protein kinases known as the mitogen-activated protein kinase (MAPK) family. JNK is an important signaling component that converts external stimuli into a wide range of cellular responses, including cell proliferation, differentiation, survival, migration, invasion, and apoptosis, as well as the development of inflammation, fibrosis, cancer growth, and metabolic diseases. Because of the essential roles of JNK in these cellular functions, deregulated JNK is often found to contribute to the development of HCC. Recently, the functions and molecular mechanisms of JNK in HCC development have been addressed using mouse models and human HCC cell lines. Furthermore, recent studies demonstrate that the activation of JNK by oncogenes can promote the development of cancers by regulating the transforming growth factor (TGF)-β/Smad pathway, which makes the oncogenes/JNK/Smad signaling pathway an attractive target for cancer therapy. Additionally, JNK-targeted therapy has a broad potential for clinical applications. In summary, we are convinced that promising new avenues for the treatment of HCC by targeting JNK are on the horizon, which will undoubtedly lead to better, more effective, and faster therapies in the years to come.

[Analysis of contribution of protein phosphorylation in the development of the diseases]

In recent decades, studies in the molecular origins of socially significant diseases have made a big step forward with the development and using of high-performance methods in genomics and proteomics. Numerous studies in the framework of the global program "Human Proteome" were aimed at the identification of all possible proteins in various cell cultures and tissues, including cancer. One of the objectives was to identify biomarkers - proteins with high specificity to certain pathologies. However, in many cases, it is shown that the development of the disease is not associated with the appearance of new proteins, but depends on the level of gene expression or forming of proteoforms - splice variants, single amino acid substitutions (SAP variants), and post-translational modifications (PTM) of proteins. PTM may play a key role in the development of pathology because they activate a variety of regulatory or structural proteins in the majority of cell physiological processes. Phosphorylation is among the most significant of these protein modifications.This review will describe methods for analysis of protein phosphorylation used in the studies of such diseases as cancer and neurodegenerative diseases, as well as examples of cases when the modified proteins are involved directly to their development, and screening such significant PTM is used for the diagnosis and choice of treatment.

Inverse association of rab31 and mucin-1 (CA15-3) antigen levels in estrogen receptor-positive (ER+) breast cancer tissues with clinicopathological parameters and patients' prognosis

Dysregulated expression of rab31, a member of the large Rab protein family of the Ras superfamily of small GTPases, has been observed in several types of cancer, including breast cancer. Rab31, depending on its expression level, may regulate the switch between an invasive versus proliferative phenotype of breast cancer cells in vitro. Moreover, gene expression of rab31 is induced by the C-terminal subunit of mucin-1 (MUC1-C) and estrogen receptors (ER). To gain further insights into the clinical relevance of rab31 and mucin-1 expression in breast cancer, we analyzed the relation between rab31 and mucin-1 (CA15-3) antigen levels in detergent tissue extracts of ER-positive (ER+) tumors and clinicopathological parameters as well as patients' prognosis. No significant correlation was observed between rab31 and CA15-3 antigen levels. Elevated rab31 antigen levels in tumor tissue extracts were significantly associated with higher tumor grade (P = 0.021). Strikingly, an inverse significant association was observed for CA15-3 with tumor grade (P = 0.032). Furthermore, high rab31 antigen levels were significantly associated with a high S-phase fraction (SPF, P = 0.047), whereas a trend for lower CA15-3 antigen levels in tumor tissue displaying higher SPF was observed. High rab31 antigen levels were significantly associated with poor 5-year disease-free survival (DFS) of ER+ breast cancer patients in univariate Cox regression analysis (HR = 1.91, 95% CI = 1.14-3.17, P = 0.013). In contrast, high levels of CA15-3 antigen levels were associated with better patients' prognosis (HR = 0.56, 95% CI = 0.33-0.95, P = 0.031). In multivariable analysis, rab31 antigen levels contributed independent prognostic information for DFS when adjusted for prognostically relevant clinicopathological parameters with a HR for high versus low values of 1.97 (95% CI = 1.09-3.54, P = 0.024), whereas CA15-3 antigen levels were not significant. Our results strongly suggest that rab31 antigen levels in tumor tissue are associated with the proliferative status, and rab31 represents an independent biomarker for prognosis in ER+ breast cancer patients. Total mucin-1 (CA 15-3) levels are rather inversely associated with tumor grade and SPF, and elevated levels even indicate prolonged DFS in ER+ breast cancer patients.

Glucose Limitation Alters Glutamine Metabolism in MUC1-Overexpressing Pancreatic Cancer Cells

Pancreatic cancer cells overexpressing Mucin 1 (MUC1) rely on aerobic glycolysis and, correspondingly, are dependent on glucose for survival. Our NMR metabolomics comparative analysis of control (S2–013.Neo) and MUC1-overexpressing (S2–013.MUC1) cells demonstrates that MUC1 reprograms glutamine metabolism upon glucose limitation. The observed alteration in glutamine metabolism under glucose limitation was accompanied by a relative decrease in the proliferation of MUC1-overexpressing cells compared with steady-state conditions. Moreover, glucose limitation induces G1 phase arrest where S2–013.MUC1 cells fail to enter S phase and synthesize DNA because of a significant disruption in pyrimidine nucleotide biosynthesis. Our metabolomics analysis indicates that glutamine is the major source of oxaloacetate in S2–013.Neo and S2–013.MUC1 cells, where oxaloacetate is converted to aspartate, an important metabolite for pyrimidine nucleotide biosynthesis. However, glucose limitation impedes the flow of glutamine carbons into the pyrimidine nucleotide rings and instead leads to a significant accumulation of glutamine-derived aspartate in S2–013.MUC1 cells.

Conditional abrogation of transforming growth factor-β receptor 1 in PTEN-inactivated endometrium promotes endometrial cancer progression in mice

Although a putative role for transforming growth factor-β (TGFB) signalling in the pathogenesis of human endometrial cancer has long been proposed, the precise function of TGFB signalling in the development and progression of endometrial cancer remains elusive. Depletion of phosphatase and tensin homologue (PTEN) in the mouse uterus causes endometrial cancer. To identify the potential role of TGFB signalling in endometrial cancer, we simultaneously deleted TGFB receptor 1 (Tgfbr1) and Pten in the mouse uterus by using Cre-recombinase driven by the progesterone receptor (termed Pten^d/d ;Tgfbr1^d/d ). We found that Pten^d/d ;Tgfbr1^d/d mice developed severe endometrial lesions that progressed more rapidly than those resulting from conditional deletion of Pten alone, suggesting that TGFB signalling synergizes with PTEN to suppress endometrial cancer progression. Remarkably, Pten^d/d ;Tgfbr1^d/d mice developed distant pulmonary metastases, leading to a significantly reduced lifespan. The development of metastasis and accelerated tumour progression in Pten^d/d ;Tgfbr1^d/d mice are associated with increased production of proinflammatory chemokines, enhanced cancer cell motility, as shown by myometrial invasion and disruption, and an altered tumour microenvironment characterized by recruitment of tumour-associated macrophages. Thus, conditional deletion of Tgfbr1 in PTEN-inactivated endometrium leads to a disease that recapitulates invasive and lethal human endometrial cancer. This mouse model may be valuable for preclinical testing of new cancer therapies, particularly those targeting metastasis, one of the hallmarks of cancer and a major cause of death in endometrial cancer patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Role of liver ICAM-1 in metastasis

Intercellular adhesion molecule (ICAM)-1, is a transmembrane glycoprotein of the immunoglobulin (Ig)-like superfamily, consisting of five extracellular Ig-like domains, a transmembrane domain and a short cytoplasmic tail. ICAM-1 is expressed in various cell types, including endothelial cells and leukocytes, and is involved in several physiological processes. Furthermore, it has additionally been reported to be expressed in various cancer cells, including melanoma, colorectal cancer and lymphoma. The majority of studies to date have focused on the expression of the ICAM-1 on the surface of tumor cells, without research into ICAM-1 expression at sites of metastasis. Cancer cells frequently metastasize to the liver, due to its unique physiology and specialized liver sinusoid capillary network. Liver sinusoidal endothelial cells constitutively express ICAM-1, which is upregulated under inflammatory conditions. Furthermore, liver ICAM-1 may be important during the development of liver metastasis. Therefore, it is necessary to improve the understanding of the mechanisms mediated by this adhesion molecule in order to develop host-directed anticancer therapies.

Anti-MUC1 aptamer: A potential opportunity for cancer treatment

Mucin 1 (MUC1) is a protein usually found on the apical surface of most normal secretory epithelial cells. However, in most adenocarcinomas, MUC1 is overexpressed, so that it not only appears over the entire cell surface, but is also shed as MUC1 fragments into the blood stream. These phenomena pinpoint MUC1 as a potential target for the diagnosis and treatment of cancer; consequently, interest has increased in MUC1 as a molecular target for overcoming cancer therapy challenges. MUC1 currently ranks second among 75 antigen candidates for cancer vaccines, and different antibodies or aptamers against MUC1 protein are proving useful for tracing cancer cells in the emerging field of targeted delivery. The unique properties of MUC1 aptamers as novel targeting agents, and the revolutionary role that MUC1 now plays in cancer therapy, are the focus of this review. Recent advancements in MUC1-targeted cancer therapy are also assessed.

Role of integrin-linked kinase in regulating the protein stability of the MUC1-C oncoprotein in pancreatic cancer cells

MUC1-C overexpression has been associated with the progression of pancreatic tumors by promoting the aggressive and metastatic phenotypes. As MUC1 is a STAT3 target gene, STAT3 plays a major role in regulating MUC1-C expression. In this study, we report an alternative mechanism by which integrin-linked kinase (ILK) post-transcriptionally modulates the expression of MUC1-C by maintaining its protein stability in pancreatic cancer cells. We found that ILK acts in concert with STAT3 to facilitate IL-6-mediated upregulation of MUC1-C; ILK depletion was equally effective as STAT3 depletion in abolishing IL-6-induced MUC1-C overexpression without disturbing the phosphorylation or cellular distribution of STAT3. Conversely, ectopic expression of constitutively active ILK increased MUC1-C expression, though this increase was not noted with kinase-dead ILK. This finding suggests the requirement of the kinase activity of ILK in regulating MUC1-C stability, which was confirmed by using the ILK kinase inhibitor T315. Furthermore, our data suggest the involvement of protein kinase C (PKC)δ in mediating the suppressive effect of ILK inhibition on MUC1-C repression. For example, co-immunoprecipitation analysis indicated that ILK depletion-mediated MUC1-C phosphorylation was accompanied by increased phosphorylation of PKCδ at the activation loop Thr-507 and increased binding of PKCδ to MUC1-C. Conversely, ILK overexpression resulted in decreased PKCδ phosphorylation. From a mechanistic perspective, the present finding, together with our recent report that ILK controls the expression of oncogenic KRAS through a regulatory loop, underscores the pivotal role of ILK in promoting pancreatic cancer progression.

Targeting MUC1 and JNK by RNA interference and inhibitor inhibit the development of hepatocellular carcinoma

Mucin 1 (MUC1), as an oncogene, is overexpressed in hepatocellular carcinoma (HCC) cells and promotes the progression and tumorigenesis of HCC through JNK/TGF-β signaling pathway. In the present study, RNA interference (RNAi) and JNK inhibitor SP600125, which target MUC1 and/or JNK, were used to treat HCC cells in vitro, and the results showed that both silencing the expression of MUC1 and blocking the activity of JNK inhibited the proliferation of HCC cells. In addition, MUC1-stable-knockdown and SP600125 significantly inhibited the growth of tumors in the subcutaneous transplant tumor models that established in BALB/c nude mice rather than MUC1 or JNK siRNAs transiently transfection. Furthermore, the results from immunohistochemical staining assays showed that the inhibitory effects of MUC1 gene silencing and SP600125 on the proliferation of HCC cells in vivo were through the JNK/TGF-β signaling pathway. These results indicate that MUC1 and JNK are attractive targets for HCC therapy and may provide new therapeutic strategies for the treatment of HCC.

Serum Wisteria Floribunda Agglutinin-Positive Sialylated Mucin 1 as a Marker of Progenitor/Biliary Features in Hepatocellular Carcinoma

Histological molecular classification of hepatocellular carcinoma (HCC) is clinically important for predicting the prognosis. However, a reliable serum marker has not been established. The aim of this study was to evaluate the diagnostic value of serum Wisteria Floribunda agglutinin-positive sialylated mucin 1 (WFA-sialylated MUC1), which is a novel biliary marker, as a marker of HCC with hepatic progenitor cell (HPC)/biliary features and of prognosis. A total of 144 consecutive patients who underwent complete radiofrequency ablation of primary HCC were enrolled. A serum WFA-sialylated MUC1 level of 900 μL/mL was determined as the optimal cutoff value for prediction of immunohistochemical staining for HPC/biliary features [sialylated MUC1 and cytokeratin 19 (CK19)]. Positive staining rate of sialylated MUC1 and CK19 was significantly higher in patients with WFA-sialylated MUC1 ≥900 than those with WFA-sialylated MUC1 <900. Furthermore, cumulative incidence of HCC recurrence was significantly higher in patients with WFA-sialylated MUC1 ≥900 and on multivariate analysis, serum WFA-sialylated MUC1 levels was an independent predictor of HCC recurrence. These results revealed that serum WFA-sialylated MUC1 was associated with histological feature of HCC and recurrence after curative therapy and it could be a novel marker of HPC/biliary features in HCC and of prognosis.