Adipocytes Promote Breast Cancer Cell Survival and Migration through Autophagy Activation

Inhibiting SNX10 induces autophagy to suppress invasion and EMT and inhibits the PI3K/AKT pathway in cervical cancer

PURPOSE

Cervical cancer (CC) is a prevalent malignancy among women with high morbidity and poor prognosis. Sorting nexin 10 (SNX10) is a newly recognized cancer regulatory factor, while its action on CC progression remains elusive. Hence, this study studied the effect of SNX10 on CC development and investigated the mechanism.

METHODS

The SNX10 level in CC and the overall survival of CC cases with different SNX10 expressions were determined by bioinformatics analysis in GEPIA. The SNX10 expression in tumor tissues and clinical significance were studied in 64 CC cases. The overall survival was assessed using Kaplan-Meier analysis. The formation of LC3 was evaluated using immunofluorescence. Cell invasion was measured using the Transwell assay. Epithelial-to-mesenchymal transition (EMT) was determined by observing cell morphology and assessing EMT marker levels. A xenograft tumor was constructed to evaluate tumor growth.

RESULTS

SNX10 was elevated in CC tissues and cells, and the CC cases with high SNX10 levels exhibited poor overall survival. Besides, SNX10 correlated with the FIGO stage, lymph node invasion, and stromal invasion of CC. SNX10 silencing induced CC cell autophagy and suppressed CC cell invasion and EMT. Meanwhile, silenced SNX10 could suppress invasion and EMT via inducing autophagy. Furthermore, SNX10 inhibition suppressed the PI3K/AKT pathway. Moreover, silenced SNX10 restrained the tumor growth, autophagy, and EMT of CC in vivo.

CONCLUSION

SNX10 was enhanced in CC and correlated with poor prognosis. Silenced SNX10 induced autophagy to suppress invasion and EMT and inhibited the PI3K/AKT pathway in CC, making SNX10 a valuable molecule for CC therapy.

Molecular and cellular mechanisms of chemoresistance in paediatric pre-B cell acute lymphoblastic leukaemia

Paediatric patients with relapsed B cell acute lymphoblastic leukaemia (B-ALL) have poor prognosis, as relapse-causing clones are often refractory to common chemotherapeutics. While the molecular mechanisms leading to chemoresistance are varied, significant evidence suggests interactions between B-ALL blasts and cells within the bone marrow microenvironment modulate chemotherapy sensitivity. Importantly, bone marrow mesenchymal stem cells (BM-MSCs) and BM adipocytes are known to support B-ALL cells through multiple distinct molecular mechanisms. This review discusses the contribution of integrin-mediated B-ALL/BM-MSC signalling and asparagine supplementation in B-ALL chemoresistance. In addition, the role of adipocytes in sequestering anthracyclines and generating a BM niche favourable for B-ALL survival is explored. Furthermore, this review discusses the role of BM-MSCs and adipocytes in promoting a quiescent and chemoresistant B-ALL phenotype. Novel treatments which target these mechanisms are discussed herein, and are needed to improve dismal outcomes in patients with relapsed/refractory disease.

Breast tumor-on-chip: from the tumor microenvironment to medical applications

With the development of microfluidic technology, tumor-on-chip models have gradually become a new tool for the study of breast cancer because they can simulate more key factors of the tumor microenvironment compared with traditional models in vitro. Here, we review up-to-date advancements in breast tumor-on-chip models. We summarize and analyze the breast tumor microenvironment (TME), preclinical breast cancer models for TME simulation, fabrication methods of tumor-on-chip models, tumor-on-chip models for TME reconstruction, and applications of breast tumor-on-chip models and provide a perspective on breast tumor-on-chip models. This review will contribute to the construction and design of microenvironments for breast tumor-on-chip models, even the development of the pharmaceutical field, personalized/precision therapy, and clinical medicine.

Cancer/testis antigen CAGE mediates osimertinib resistance in non-small cell lung cancer cells and predicts poor prognosis in patients with pulmonary adenocarcinoma

CAGE, a cancer/testis antigen, was originally isolated from the sera of patients with gastric cancers. Previously, we have shown the role of CAGE in resistance to chemotherapy and target therapy. The aim of this study was to investigate the role of CAGE in osimertinib resistance and determine the prognostic value of CAGE in patients with pulmonary adenocarcinomas. The clinicopathological correlation with CAGE and autophagy flux in patients was examined using immunohistochemistry and in situ hybridization. The possible role of autophagy in osimertinib resistance was analyzed using immune blot, immune fluorescence staining and immunohistochemistry. This study found that immunohistochemical staining (IHC) showed CAGE expression in more than 50% of patients with pulmonary adenocarcinomas (pADCs). CAGE expression was increased in pADCs after the acquisition of EGFR-TKIs resistance. High expression of CAGE was correlated with shorter overall survival and progression free survival in patients with pADCs. Thus, CAGE mediates osimertinib resistance and predicts poor prognosis in patients with pADCs. Osimertinib-resistant non-small cell lung cancer cells (PC-9/OSI) were established and mechanistic studies of CAGE-mediated osimertinib resistance were performed. PC-9/OSI cells showed increased autophagic flux and CAGE expression compared with parental sensitive PC-9 cells. PC-9/OSI cells showed higher tumorigenic, metastatic, and angiogenic potential compared with parental PC-9 cells. CAGE CRISPR-Cas9 cell lines showed decreased autophagic flux, invasion, migration potential, and tumorigenic potential compared with PC-9/OSI cells in vitro and in vivo. CAGE plays a crucial role in the cancer progression by modulating autophagy and can predict the poor prognosis of patients with pulmonary adenocarcinomas. Our findings propose CAGE as a potential therapeutic target for developing anticancer drugs that can overcome osimertinib resistance.

Effects of adipocyte-conditioned cell culture media on S1P treatment of human triple-negative breast cancer cells

Sphingosine-1-phosphate (S1P) is a potent sphingolipid metabolite that regulates a wide range of biological functions such as cell proliferation, cell apoptosis and angiogenesis. Its cellular level is elevated in breast cancer, which, in turn, would promote cancer cell proliferation, survival, growth and metastasis. However, the cellular concentration of S1P is normally in the low nanomolar range, and our previous studies showed that S1P selectively induced apoptosis of breast cancer cells at high concentrations (high nanomolar to low micromolar). Thus, local administration of high-concentration S1P alone or in combination of chemotherapy agents could be used to treat breast cancer. The breast mainly consists of mammary gland and connective tissue stroma (adipose), which are dynamically interacting each other. Thus, in the current study, we evaluated how normal adipocyte-conditioned cell culture media (AD-CM) and cancer-associated adipocyte-conditioned cell culture media (CAA-CM) would affect high-concentration S1P treatment of triple-negative breast cancer (TNBC) cells. Both AD-CM and CAA-CM may suppress the anti-proliferative effect and reduce nuclear alteration/apoptosis caused by high-concentration S1P. This implicates that adipose tissue is likely to be detrimental to local high-concentration S1P treatment of TNBC. Because the interstitial concentration of S1P is about 10 times higher than its cellular level, we undertook a secretome analysis to understand how S1P would affect the secreted protein profile of differentiated SGBS adipocytes. At 100 nM S1P treatment, we identified 36 upregulated and 21 downregulated secretome genes. Most of these genes are involved in multiple biological processes. Further studies are warranted to identify the most important secretome targets of S1P in adipocytes and illustrate the mechanism on how these target proteins affect S1P treatment of TNBC.

Changes in the mammary gland during aging and its links with breast diseases

The functional capacity of organisms declines in the process of aging. In the case of breast tissue, abnormal mammary gland development can lead to dysfunction in milk secretion, a primary function, as well as the onset of various diseases, such as breast cancer. In the process of aging, the terminal duct lobular units (TDLUs) within the breast undergo gradual degeneration, while the proportion of adipose tissue in the breast continues to increase and hormonal levels in the breast change accordingly. Here, we review changes in morphology, internal structure, and cellular composition that occur in the mammary gland during aging. We also explore the emerging mechanisms of breast aging and the relationship between changes during aging and breast-related diseases, as well as potential interventions for delaying mammary gland aging and preventing breast disease.

Towards dual function of autophagy in breast cancer: A potent regulator of tumor progression and therapy response

As a devastating disease, breast cancer has been responsible for decrease in life expectancy of females and its morbidity and mortality are high. Breast cancer is the most common tumor in females and its treatment has been based on employment of surgical resection, chemotherapy and radiotherapy. The changes in biological behavior of breast tumor relies on genomic and epigenetic mutations and depletions as well as dysregulation of molecular mechanisms that autophagy is among them. Autophagy function can be oncogenic in increasing tumorigenesis, and when it has pro-death function, it causes reduction in viability of tumor cells. The carcinogenic function of autophagy in breast tumor is an impediment towards effective therapy of patients, as it can cause drug resistance and radio-resistance. The important hallmarks of breast tumor such as glucose metabolism, proliferation, apoptosis and metastasis can be regulated by autophagy. Oncogenic autophagy can inhibit apoptosis, while it promotes stemness of breast tumor. Moreover, autophagy demonstrates interaction with tumor microenvironment components such as macrophages and its level can be regulated by anti-tumor compounds in breast tumor therapy. The reasons of considering autophagy in breast cancer therapy is its pleiotropic function, dual role (pro-survival and pro-death) and crosstalk with important molecular mechanisms such as apoptosis. Moreover, current review provides a pre-clinical and clinical evaluation of autophagy in breast tumor.

The pleiotropic roles of adipocyte secretome in remodeling breast cancer

Background

Breast cancer is the leading female cancer type and the cause of cancer-related mortality worldwide. Adipocytes possess important functions of energy supply, metabolic regulation, and cytokine release, and are also the matrix cell that supports mammary gland tissue. In breast cancer tumor microenvironment (TME), adipocytes are the prominent stromal cells and are implicated in inflammation, metastatic formation, metabolic remodeling, and cancer susceptibility.

Main body

It is well-established that adipocyte secretome is a reservoir engaged in the regulation of tumor cell behavior by secreting a large number of cytokines (IL-6, IL-8, and chemokines), adipokines (leptin, adiponectin, autotaxin, and resistin), lipid metabolites (free fatty acids and β-hydroxybutyrate), and other exosome-encapsulated substances. These released factors influence the evolution and clinical outcome of breast cancer through complex mechanisms. The progression of breast cancer tumors revolves around the tumor-adipose stromal network, which may contribute to breast cancer aggressiveness by increasing the pro-malignant potential of TME and tumor cells themselves. Most importantly, the secretome alterations of adipocytes are regarded as distinctly important targets for breast cancer diagnosis, treatment, and drug resistance.

Conclusion

Therefore, this review will provide a comprehensive description of the specific adipocyte secretome characteristics and interactions within TME cell populations, which will enable us to better tailor strategies for tumor stratification management and treatment.