Glycotherapy: A New Paradigm in Breast Cancer Research

RPN1 promotes the proliferation and invasion of breast cancer cells by activating the PI3K/AKT/mTOR signaling pathway

Ribophorin I (RPN1), a part of an N-oligosaccharyl-transferase complex, plays a vital role in the development of multiple cancers. However, its biological role in breast cancer has not been completely clarified. The RPN1 expression level was measured in breast cancer tissues and breast cancer cell lines (MCF7) using RT-qPCR. After down-regulating RPN1 expression by shRNA, the effects of RPN1 on the proliferation, migration and invasion of MCF7 cells were examined. Mechanistically, we assessed the effect of RPN1 on the PI3K/ AKT/mTOR signaling pathway. We found that RPN1 level was up-regulated in breast cancer tissues and cells compared with adjacent non-tumor tissues or MCF10A cells. RPN1 knockdown induced apoptosis and attenuated the proliferation, migration, and invasion of MCF7 cells. Moreover, RPN1 knockdown lowered the levels of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, which were rescued by 740Y-P, a PI3K activator. 740Y-P also reversed the effects of RPN1 knockdown on apoptosis, proliferation, migration, and invasion in MCF7 cells. Taken together, RPN1 promotes the proliferation, migration, and invasion of breast cancer cells via the PI3K/AKT/mTOR signaling pathway.

The linkage between IL-6 rs1800797 variant and breast cancer susceptibility in Bangladeshi women: A case-control study

Background and Aims

Breast cancer is one of the deadliest diseases affecting women in Bangladesh, and its prevalence is increasing year by year. Although several IL-6 single nucleotide polymorphisms have been implicated in BC susceptibility and prognosis in various studies, no research has been done to investigate the relationship between breast cancer and IL-6 in Bangladeshi women. This investigation aimed to explore the linkage between the rs1800797 variant of IL-6 and the susceptibility to breast carcinoma among women in Bangladesh.

Methods

The IL-6 rs1800797 variant was genotyped in 218 subjects (110 cases and 108 controls) using the tetra-primer ARMS-PCR method. The statistical analysis was applied utilizing the SPSS software version 24.0. UALCAN database was used for IL-6 mRNA analysis, and genotype-based gene expression was retrieved from GTEx Portal.

Results

This study found a significant link between IL-6 rs1800797 variants and increased chance of breast cancer across different genetic inheritance models, including additive model 1 (AG vs. GG: OR = 2.16, p = 0.035); dominant model (AG + AA vs. GG: OR = 2.26, p < 0.05); overdominant model (AG vs. GG + AA: OR = 2.08, p < 0.05); and allelic model (A vs. G: OR = 2.15, p < 0.05). However, an insignificant association of breast cancer was found in both additive model 2 (AA vs. GG: OR = 2.91, p > 0.05) and the recessive model (AA vs. GG + AG: OR = 2.52, p > 0.05). Under the analysis of the probability of false positive reports, no significant values were found in different models when the OR was 1.5, and the prior probability was 0.25.

Conclusions

A significant relationship was found between the IL-6 rs1800797 genetic variant and the risk of breast cancer. However, the findings of the study should be further investigated with a larger sample size to validate the correlation.

BIRTH OF A GLYCOTHERAPY FOR BREAST CANCER

Breast cancer is the most common malignant disease in women and is worldwide. The incidence rate of women's breast cancer in 2020 was 2,261,419 and 2022 estimates diagnosing 1,918,030 cases. The disease is heterogeneous and the pathogenesis of breast cancer still remains unclear. Much progress has been made in early detection and better treatment to improve survival. Unfortunately, the current treatment strategies destroy the patient's quality of life. The patients develop drug resistance, exhibit severe side effects, and not afford the cost creates anxiety among the patients, families, and friends. In addition, a considerable number of patients relapse as a result of organ metastasis, e.g., the triple-negative breast cancer (TNBC, ER-/PR-HER2-). The 5-year survival rate of patients who recurred with distant metastasis is less than 20%. More than half a million women worldwide still suffer from metastatic breast cancer annually, and 90% of their deaths could be attributed to metastasis. One of the reasons for the failure of cancer therapeutics is the approaches did not consider the cancer holistically. All breast cancer cells and their micro environmental capillary endothelial cells express asparagine-linked (N-linked) glycoproteins. We have tested a biologic and a small molecule, Tunicamycin-P (P = pure N-glycosylation inhibitor) to interfere with the protein N-glycosylation pathway in the endoplasmic reticulum (ER) by specifically blocking the catalytic activity of N-acetylglusosaminyl 1-phosphate transferase (GPT) activity. The outcome has been quantitative inhibition of in vitro and in vivo angiogenesis and the breast tumor progression of multiple subtypes in pre-clinical mouse models with "zero" toxicity. We have, therefore, concluded that Tunicamycin-P is expected to supersede the current therapeutics and become a Glycotherapy treating breast cancer of all subtypes.

Endoplasmic reticulum-quality control pathway and endoplasmic reticulum-associated degradation mechanism regulate the N-glycoproteins and N-glycan structures in the diatom Phaeodactylum tricornutum

Tunicamycin inhibits the first step of protein N-glycosylation modification. However, the physiological, transcriptomic, and N-glycomic effects of tunicamycin on important marine diatom Phaeodactylum tricornutum are still unknown. In this study, comprehensive approaches were used to study the effects of tunicamycin stress. The results showed that cell growth and photosynthesis were significantly inhibited in P. tricornutum under the tunicamycin stress. The soluble protein content was significantly decreased, while the soluble sugar and neutral lipid were dramatically increased to orchestrate the balance of carbon and nitrogen metabolisms. The stress of 0.3 μg ml^-1 tunicamycin resulted in the differential expression of ERQC and ERAD related genes. The upregulation of genes involved in ERQC pathway, the activation of anti-oxidases and the differential expression of genes related with ERAD mechanism might be important for maintaining homeostasis in cell. The identification of N-glycans, especially complex-type N-glycan structures enriched the N-glycan database of diatom P. tricornutum and provided important information for studying the function of N-glycosylation modification on proteins. As a whole, our study proposed working models of ERQC and ERAD will provide a solid foundation for further in-depth study of the related mechanism and the diatom expression system.