Inhibition of KL-6/MUC1 glycosylation limits aggressive progression of pancreatic cancer

Krebs von den Lungen 6 (KL-6) is a novel diagnostic and prognostic biomarker in pleural mesothelioma

OBJECTIVES

Pleural mesothelioma (PM) is a rare disease with dismal outcome. Systemic treatment options include chemotherapy and immunotherapy, but biomarkers for treatment personalization are missing. The only FDA-approved diagnostic biomarker is the soluble mesothelin-related protein (SMRP). Krebs von den Lungen-6 (KL-6) is a human mucin 1 (MUC1) glycoprotein, which has shown diagnostic and prognostic value as a biomarker in other malignancies. The present study investigated whether KL-6 can serve as a diagnostic and/or prognostic biomarker in PM.

MATERIALS AND METHODS

Using a fully-automated chemiluminescence enzyme immunoassay (CLEIA) for KL-6 and SMRP, pleural effusion samples from 87 consecutive patients with PM and 25 patients with non-malignant pleural disorders were studied. In addition, KL-6 and SMRP levels were determined in corresponding patient sera, and in an independent validation cohort (n = 122). MUC1 mRNA and protein expression, and KL-6 levels in cell line supernatants were investigated in PM primary cell lines in vitro.

RESULTS

PM patients had significantly higher KL-6 levels in pleural effusion than non-malignant controls (AUC 0.78, p < 0.0001). Among PM patients, levels were highest in those with epithelioid or biphasic histologies. There was a strong positive correlation between pleural effusion levels of KL-6 and SMRP (p < 0.0001). KL-6 levels in sera similarly associated with diagnosis of PM, however, to a lesser extent (AUC 0.71, p = 0.008). PM patients with high pleural effusion KL-6 levels (≥303 IU/mL) had significantly better overall survival (OS) compared to those with low KL-6 levels (HR 0.51, p = 0.004). Congruently, high tumor cell MUC1 mRNA expression in primary cell lines associated with prolonged corresponding patient OS (HR 0.35, p = 0.004). These findings were confirmed in an independent validation cohort.

CONCLUSION

This is the first study demonstrating KL-6 as a potential novel liquid-based diagnostic and prognostic biomarker in PM.

Comparative study on the antitumor effects of gemcitabine polybutylcyanoacrylate nanoparticles coupled with anti-human MUC1 and CA199 monoclonal antibodies on pancreatic cancer in vitro and in vivo

BACKGROUND AND STUDY AIMS

This study was designed to compare the antitumor effects of anti-human MUC1 monoclonal antibody with those of anti-human CA199 monoclonal antibody coupled with drug-loaded polybutylcyanoacrylate nanoparticles on human pancreatic cancer cell lines and pancreatic cancer-bearing model animals and to screen more efficient targeting molecules.

PATIENTS AND METHODS

Gemcitabine-loaded nanospheres were prepared by emulsion polymerization (GEM-PBCA-NP), and then, anti-MUC1 monoclonal antibody was coupled with GEM-PBCA-NP (MUC1-GEM-PBCA-NP), and anti-human CA199 monoclonal antibody was coupled with GEM-PBCA-NP (CA199-GEM-PBCA-NP), using the chemical crosslinking method. The cell-killing rates were detected using MTT assay. The changes in the tumor cell cycle and apoptosis after treatment were detected using flow cytometry. Then, the subcutaneous planting method was adopted to establish an animal model of pancreatic cancer: two nanometer microspheres were injected into the body of nude mice via the tail vein; the tumor suppression effect was detected after treatment; then, the groups were compared.

RESULTS

In vitro, the cell-killing rate of each experimental group was significantly different from that of the control group (P < 05). The MUC1-GEM-PBCA-NP group had a significantly higher cell-killing rate than the other groups (P < 05). The apoptosis rate of the MUC1-GEM-PBCA-NP treatment group was significantly higher than that of other groups (P < 05). In vivo, the tumor inhibition rate of the MUC1-GEM-PBCA-NP treatment group was 72.69% ± 4.29%, which was significantly higher than those of other groups (P < 0.05). The tumor inhibition rate of the CA199-GEM-PBCA-NP treatment group was 56.58% ± 5.11%, which was significantly higher than those of other control groups (P < 0.05). At the end of treatment, the average tumor mass of the MUC1-GEM-PBCA-NP treatment group was 433.55 ± 12.49 mg, which was significantly lower than those of other groups (P < 0.05).

CONCLUSION

Compared with CA199-GEM-PBCA-NP, MUC1-GEM-PBCA-NP is more effective in vitro and in vivo. MUC1 could be a target molecule in treating pancreatic cancer.

Glycosylated modification of MUC1 maybe a new target to promote drug sensitivity and efficacy for breast cancer chemotherapy

Breast cancer, the most common cancer in women, usually exhibits intrinsic insensitivity to drugs, even without drug resistance. MUC1 is a highly glycosylated transmembrane protein, overexpressed in breast cancer, contributing to tumorigenesis and worse prognosis. However, the molecular mechanism between MUC1 and drug sensitivity still remains unclear. Here, natural flavonoid apigenin was used as objective due to the antitumor activity and wide availability. MUC1 knockout (KO) markedly sensitized breast cancer cells to apigenin cytotoxicity in vitro and in vivo. Both genetical and pharmacological inhibition significantly enhanced the chemosensitivity to apigenin and clinical drugs whereas MUC1 overexpression conversely aggravated such drug resistance. Constitutively re-expressing wild type MUC1 in KO cells restored the drug resistance; however, the transmembrane domain deletant could not rescue the phenotype. Notably, further investigation discovered that membrane-dependent drug resistance relied on the extracellular glycosylated modification since removing O-glycosylation via inhibitor, enzyme digestion, or GCNT3 (MUC1 related O-glycosyltransferase) knockout markedly reinvigorated the chemosensitivity in WT cells, but had no effect on KO cells. Conversely, inserting O-glycosylated sites to MUC1-N increased the drug tolerance whereas the O-glycosylated deletant (Ser/Thr to Ala) maintained high susceptibility to drugs. Importantly, the intracellular concentration of apigenin measured by UPLC and fluorescence distribution firmly revealed the increased drug permeation in MUC1 KO and BAG-pretreated cells. Multiple clinical chemotherapeutics with small molecular were tested and obtained the similar conclusion. Our findings uncover a critical role of the extracellular O-glycosylation of MUC1-N in weakening drug sensitivity through acting as a barrier, highlighting a new perspective that targeting MUC1 O-glycosylation has great potential to promote drug sensitivity and efficacy.

Update on the role of C1GALT1 in cancer (Review)

Cancer remains one of the most difficult diseases to treat. In the quest for early diagnoses to improve patient survival and prognosis, targeted therapies have become a hot research topic in recent years. Glycosylation is the most common posttranslational modification in mammalian cells. Core 1β1,3-galactosyltransferase (C1GALT1) is a key glycosyltransferase in the glycosylation process and is the key enzyme in the formation of the core 1 structure on which most complex and branched O-glycans are formed. A recent study reported that C1GALT1 was aberrantly expressed in tumors. In cancer cells, C1GALT1 is regulated by different factors. In the present review, the expression of C1GALT1 in different tumors and its possible molecular mechanisms of action are described and the role of C1GALT1 in cancer development is discussed.

MUC1: Structure, Function, and Clinic Application in Epithelial Cancers

The transmembrane glycoprotein mucin 1 (MUC1) is a mucin family member that has different functions in normal and cancer cells. Owing to its structural and biochemical properties, MUC1 can act as a lubricant, moisturizer, and physical barrier in normal cells. However, in cancer cells, MUC1 often undergoes aberrant glycosylation and overexpression. It is involved in cancer invasion, metastasis, angiogenesis, and apoptosis by virtue of its participation in intracellular signaling processes and the regulation of related biomolecules. This review introduces the biological structure and different roles of MUC1 in normal and cancer cells and the regulatory mechanisms governing these roles. It also evaluates current research progress and the clinical applications of MUC1 in cancer therapy based on its characteristics.

Construction of a Ternary Complex Based DNA Logic Nanomachine for a Highly Accurate Imaging Analysis of Cancer Cells

Due to the complexity and variability of the cellular metabolic process and the physiological environment inside and outside the cell, higher requirements are needed on the application of DNA molecular logic gate in cell analysis. In addition, heterogeneity of tumor cells tends to lead to false positives in the clinical diagnosis of a single target, even those with the same cancer type. To address these issues above, we have developed a novel DNA molecular logic gate responsive nanomachine for bispecific recognition and computation of cell membranes. Only when two membrane proteins, MUC1 and EpCAM as model proteins, exist simultaneously, the DNA molecular logic gate can be activated to perform "AND" logic operation and generate amplified "ON" fluorescence signal from the cell membrane. Therefore, our proposed dual-specific "recognition-biocomputing" DNA molecular logic gate has achieved highly accurate imaging analysis of dual-target membrane proteins in situ. Furthermore, the logic gate responsive DNA nanomachine can also be used to analyze target cells in complex cell samples with excellent specificity, which will meet the needs of biomedicine and their application in clinical diagnosis and provide new tools for the biomedical application of DNA molecular logic gates in complex cell systems.

The glycosylation landscape of pancreatic cancer

Pancreatic adenocarcinoma is a lethal disease with a 5-year survival rate of <5%, the lowest of all types of cancer. The diagnosis of pancreatic cancer relies on imaging and tissue biopsy, and the only curative therapy is complete surgical resection. Pancreatic cancer has the propensity to metastasise at an early stage and the majority of patients are diagnosed when surgery is no longer an option. Hence, there is an urgent need to identify biomarkers to enable early diagnosis, and to develop new therapeutic strategies. One approach for this involves targeting cancer-associated glycans. The most widely used serological marker in pancreatic cancer is the carbohydrate antigen CA 19-9 which contains a glycan known as sialyl Lewis A (sLeA). The CA 19-9 assay is used routinely to monitor response to treatment, but concerns have been raised about its sensitivity and specificity as a diagnostic biomarker. In addition to sLeA, a wide range of alterations to other important glycans have been observed in pancreatic cancer. These include increases in the sialyl Lewis X antigen (sLex), an increase in truncated O-glycans (Tn and sTn), increased branched and fucosylated N-glycans, upregulation of specific proteoglycans and galectins, and increased O-GlcNAcylation. Growing evidence supports crucial roles for glycans in all stages of cancer progression, and it is well established that glycans regulate tumour proliferation, invasion and metastasis. The present review describes the biological significance of glycans in pancreatic cancer, and discusses the clinical value of exploiting aberrant glycosylation to improve the diagnosis and treatment of this deadly disease.

Clinic implication of MUC1 O-glycosylation and C1GALT1 in esophagus squamous cell carcinoma

Esophagus squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumors in the world. Our previous data demonstrates that oncoprotein MUC1 is related with metastasis and poor outcome of ESCC. However, alteration of MUC1 in ESCC remains unclear. Using ONCOMINE and COSMIC databases, we analyzed MUC1 gene copy numbers and gene mutations and found that MUC1 had high expression level but few gene mutations in ESCC. Further study of ESCC samples indicated that MUC1 O-glycosylation levels were higher in tumor tissues than that in para-carcinoma tissues in 10 of 14 pairs of ESCC samples. Moreover, we verified a potential link between MUC1 O-glycosylation and C1GALT1, which was further supported by IHC analysis on 38 ESCC and 19 para-carcinoma samples. More importantly, co-expression of MUC1 Oglycosylation and C1GALT1 presented positive correlations with both lymph node metastasis and survival time of ESCC patients. Our work collectively indicates that C1GALT1 is associated with O-glycosylated MUC1 in ESCC, not only suggesting a diagnostic significance of C1GALT1 and MUC1 O-glycosylation in ESCC, but also opening novel insights into targeting C1GALT1 and MUC1 O-glycosylation to suppress ESCC cells metastasis in patients.

Serum carbohydrate antigen 153 and renal function in patients with type 2 diabetes mellitus

OBJECTIVE

The aim of our study was to investigate the correlation between serum carbohydrate antigen 153 (CA153) and renal function in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 184 patients with T2DM were included, and renal function was assessed by the modification of diet in renal disease (MDRD) formula adjusted coefficient of the Chinese people.

RESULTS

Serum CA153 concentrations were positively correlated with blood glucose (BG) and glycated hemoglobin (HbA1c) (r = .204, P = .005; r = .165, P = .025) in patients with T2DM. There was a negative correlation between serum CA153 and estimated glomerular filtration rate (GFR) (r = -.229, P = .002) in whole patients with T2DM; similarly, the correlations were observed in both women and men (r = -.228, P = .028 for women, r = -.231, P = .028 for men). Multiple linear regression analysis suggested that serum CA153 was still significantly correlated with estimated GFR (beta = -0.286, P < .001).

CONCLUSIONS

Serum CA153 is negatively correlated with estimated GFR in patients with T2DM, and serum CA153 may be a potentially useful clinical biomarker to assess renal function in the study population.

N-glycosylation of the transient receptor potential melastatin 8 channel is altered in pancreatic cancer cells

Transient receptor potential melastatin 8 (TRPM8), a membrane ion channel, is activated by thermal and chemical stimuli. In pancreatic ductal adenocarcinoma, TRPM8 is required for cell migration, proliferation, and senescence and is associated with tumor size and pancreatic ductal adenocarcinoma stages. Although the underlying mechanisms of these processes have yet to be described, this cation-permeable channel has been proposed as an oncological target. In this study, the glycosylation status of the TRPM8 channel was shown to affect cell proliferation, cell migration, and calcium uptake. TRPM8 expressed in the membrane of the Panc-1 pancreatic tumoral cell line is non-glycosylated, whereas human embryonic kidney cells transfected with human TRPM8 overexpress a glycosylated protein. Moreover, our data suggest that Ca²⁺ uptake is modulated by the glycosylation status of the protein, thus affecting cell proliferation.