Abstract:The protein tyrosine phosphatase 1B (PTP1B) is an important regulator of metabolism. The relationship between PTP1B and tumors is quite complex. The purpose of this study is to explore the expression pattern and role of PTP1B in breast cancer. The expression of PTP1B was detected in 67 samples of breast cancer tissue by Western blot. Cell growth assay, Transwell migration assay, and Scratch motility assay were used to examine the proliferation and migration of MCF-7 with and without PTP1B. The total levels and phosphorylated levels of signal transduction and activator of transcription 3 (STAT3) and the expression of C-C motif chemokine ligand 5 (CCL5) were also examined by Western blot. PTP1B was overexpressed in over 70% of breast cancer tissues, correlating with patients with estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and human epidermal growth factor receptor 2 (HER2)-positive tumors. The data also showed that both tumor size and lymph node metastasis were significantly higher in patients with a higher level of PTP1B. The proliferation and migration of MCF-7 cells were found to be inhibited after knocking down the gene of PTP1B. Our data also showed that PTP1B could up-regulate the dephosphorylated level of STAT3, which could increase the expression of CCL5. These phenomena indicated that PTP1B may play a crucial role in the development of breast cancer.

Ferritinophagy, a form of autophagy, is also an important part of ferroptosis, a type of regulated cell death resulting from abnormal iron metabolism involving the production of reactive oxygen species. As ferroptosis, autophagy and cancer have been revealed, ferritinophagy has attracted increasing attention in cancer development. In this review, we discuss the latest research progress on ferroptosis, autophagy-associated ferroptosis led by ferritinophagy, the regulators of ferritinophagy and promising cancer treatments that target ferritinophagy. Ferritinophagy is at the intersection of ferroptosis and autophagy and plays a significant role in cancer development. The discussed studies provide new insights into the mechanisms of ferritinophagy and promising related treatments for cancer.

Background Clinical management of triple-negative breast cancer (TNBC) patients remain challenging because of the development of chemo-resistance. Identification of biomarkers for risk stratification of chemo-resistance and therapeutic decision-making to overcome such resistance is thus necessary. Methods Retrospective analysis was performed to identify potential stratification biomarkers. The levels of ceramide kinase (CERK) was determined in breast cancer patients. The roles of CERK and its downstream signaling pathways were analysed using cellular and biochemical assays. Results CERK upregulation was identified as a biomarker for chemotherapeutic response in TNBC. A > 2-fold change in CERK (from tumor)/CERK (from normal counterpart) was significantly associated with chemo-resistance (OR = 2.66, 95% CI 1.18–7.34), P = 0.04. CERK overexpression was sufficient to promote TNBC growth and migration, and confer chemo-resistance in TNBC cell lines, although this resistance could be overcome via CERK inhibition. Mechanistic studies suggest that CERK mediates intrinsic resistance and inferior response to chemotherapy in TNBC by regulating multiple oncogenic pathways such as Ras/ERK, PI3K/Akt/mTOR, and RhoA. Conclusions Our work provides an explanation for the heterogeneity of chemo-response across TNBC patients and demonstrates that CERK inhibition offers a therapeutic strategy to overcome treatment resistance.

Abstract. Chemokine C-C motif ligand 5 (CCL5) is an important marker related to the progression of breast cancer and is upregulated in cancer cells. However, the mechanism of the overexpression of CCL5 in tumours has not yet been clarified. The present study aimed to investigate the role of endoplasmic reticulum (ER) stress in regulating CCL5 expression and its relationship with signal transducer and activator of transcription 3 (STAT3). Meanwhile, the effect of tunicamycin, a classical ER stress inducer, and CCL5 on the transmigration of human breast cancer MCF-7 cells was observed and analysed. Compared with the normal breast epithelial tissues, expression levels of CCL5, STAT3 and CHOP, an indicator of ER stress, were significantly upregulated in breast cancer tissues. In human breast cancer MCF-7 cells, ER stress activator tunicamycin increased the expression of CCL5, STAT3 and CHOP in a time-and concentration-dependent manner. Moreover, tunicamycin-induced CCL5 expression was positively related to upregulation of unphosphorylated STAT3 (U-STAT3) but negatively related to STAT3 phosphorylation at the Tyr705 site. Furthermore, ER stress inhibited CCL5 secretion and transmigration of MCF-7 cells. This study also showed that extracellular rhCCL5 induced transmigration of MCF-7 cells which was partially blocked by the CCR5 monoclonal antibody, while knockdown of endogenous expression of CCL5 did not affect the transmigration of the cells. In conclusion, ER stress induced endogenous expression of CCL5 via elevating U-STAT3 expression; however, ER stress inhibited CCL5 secretion, which in turn, decreased the transmigration of breast cancer MCF-7 cells.

Breast cancer (BC) is the world’s second most frequent malignancy and the leading cause of mortality among women. All in situ or invasive breast cancer derives from terminal tubulobular units; when the tumor is present only in the ducts or lobules in situ, it is called ductal carcinoma in situ (DCIS)/lobular carcinoma in situ (LCIS). The biggest risk factors are age, mutations in breast cancer genes 1 or 2 (BRCA1 or BRCA2), and dense breast tissue. Current treatments are associated with various side effects, recurrence, and poor quality of life. The critical role of the immune system in breast cancer progression/regression should always be considered. Several immunotherapy techniques for BC have been studied, including tumor-targeted antibodies (bispecific antibodies), adoptive T cell therapy, vaccinations, and immune checkpoint inhibition with anti-PD-1 antibodies. In the last decade, significant breakthroughs have been made in breast cancer immunotherapy. This advancement was principally prompted by cancer cells’ escape of immune regulation and the tumor’s subsequent resistance to traditional therapy. Photodynamic therapy (PDT) has shown potential as a cancer treatment. It is less intrusive, more focused, and less damaging to normal cells and tissues. It entails the employment of a photosensitizer (PS) and a specific wavelength of light to create reactive oxygen species. Recently, an increasing number of studies have shown that PDT combined with immunotherapy improves the effect of tumor drugs and reduces tumor immune escape, improving the prognosis of breast cancer patients. Therefore, we objectively evaluate strategies for their limitations and benefits, which are critical to improving outcomes for breast cancer patients. In the concluding section, we offer many avenues for further study on tailored immunotherapy, such as oxygen-enhanced PDT and nanoparticles.