Influence of Liver Pathologies on the Development and Progression of Breast Cancer: Pathophysiological Mechanisms, Therapeutic Strategies and Prevention

Goals: Ion transporters play an important regulatory role in the progression and development of breast cancer (BC). Slc26a9 is a member of the Slc26a anion transporter family, which is mainly involved in regulating the secretion of chloride ions and bicarbonate, but the role of Slc26a9 in HER2-positive BC is still unclear. Methods: Tissue microarray and BC cell line were used to detect the expression level of Slc26a9 and its clinical relevance. By changing the expression level of Slc26a9 gene in BC cells, the effect of Slc26a9 gene on the biological behavior of BC cells and its related molecular mechanism were discussed. Results: We found that the expression of Slc26a9 was significantly upregulated in BC compared with adjacent tissues, and the upregulated Slc26a9 was associated with TNM staging and poor prognosis in BC patients. In addition, the expression of Slc26a9 was significantly upregulated in HER2-positive BC compared with HER2-negative BC, and similar results were obtained in BC cell lines, with Slc26a9 was the highest expression in HER2-enriched SKBR3 cells. Functionally, the proliferation, migration, invasion and anti-apoptotic abilities of SKBR3 cells were significantly inhibited after silencing Slc26a9, and tumorigenesis and metastasis were significantly inhibited in vivo. On the contrary, overexpression of Slc26a9 resulted in the opposite result. Mechanistically, overexpression of Slc26a9 activated the PI3K/AKT/mTOR signaling pathway, the key signaling pathway implicated in HER2-positive breast carcinogenesis, and promoted the expression of downstream proliferation related genes CCND1 (Cyclin D1) and c-Myc, and downregulated the expression of apoptosis related genes Caspase9, apoptosis-inducing factor (AIF) and endonuclease G (Endo G), indicating the simultaneous inhibition of caspase dependent and independent apoptosis pathway. At the same time, accompanied by changes in markers of epithelial-mesenchymal transition (EMT), including downregulation of E-cadherin and ZO-1, and upregulation of N-cadherin and Fibronectin, and SKBR3 cells changed from epithelioid morphology to mesenchymal morphology. In addition, immunofluorescence and protein nucleoplasm separation experiments showed that Slc26a9 upregulated the expression of HER2 and co-localized with HER2 in the nucleus. Co-immunoprecipitation experiments proved that Slc26a9 interacted with HER2. Furthermore, trastuzumab downregulated the expression of Slc26a9 by targeting HER2 in SKBR3 cells. Moreover, when Slc26a9 was overexpressed, the inhibitory effect of trastuzumab on HER2 was partially reversed, and we also verified the PI3K/AKT/mTOR signaling pathway. Not only that, we found that Slc26a9 was significantly upregulated in drug-resistant cell lines relative to parental cells by constructing SKBR3 drug-resistant cell lines, indicating that Slc26a9 expression was significantly correlated with chemotherapy resistance in HER2-positive BC. Conclusion(s): Slc26a9 may interact with HER2 in the form of molecular chaperones to activate PI3K/AKT/mTOR signaling pathway to promote the progression and development of HER2-positive BC and be associated with chemotherapy resistance, but the precise molecular mechanism needs further exploration. Conflict of Interest: No significant relationships. Citation Format: Zhengxing Zhou, Zhiyuan Ma, Xuemei Liu, Chengmin Zhang, Hu Wang, Renmin Mu, Xiaoming Cheng, Biguang Tuo, Taolang Li. Slc26a9 cooperates with HER2 to regulate the progression and development of HER2-positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-26-19.

Estrogens Determine Adherens Junction Organization and E-Cadherin Clustering in Breast Cancer Cells via Amphiregulin.

Breast cancer is one of the most common malignant tumors in women, and its incidence has increased year by year, which is one of the most important causes of death among women, especially young women. Studying related cell signal transduction that affects the development and progression of breast cancer can help prevent the occurrence of breast cancer, slow down the cancer progression and improve the prognosis of patients. nitric oxide (NO) is a kind of signaling molecule. Many studies have shown that the production and expression of NO are closely related to breast cancer. NO-related cell signal transduction significantly affects the occurrence and development of breast cancer. However, the understanding of the relationship between NO and breast cancer associated cell signal transduction needs to be further improved. In this paper, the related studies on NO-related cellular signal transduction in breast cancer were reviewed with a view to improving the understanding of the development and progression of breast cancer. Key words: Nitric oxide; Breast cancer; Cell signal transduction

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States and, indeed, worldwide. It has become a global public health issue. In the United States, the prevalence in the general population is estimated at approximately 20%, while that in the morbidly obese population at approximately 75-92% and in the pediatric population at approximately 13-14%. The progressive form of NAFLD, nonalcoholic steatohepatitis, is estimated at approximately 3-5%, with approximately 3-5% of these having progressed to cirrhosis. Thus, the numbers of individuals at risk for end-stage liver disease and development of primary liver cancer is large. NAFLD is an independent risk factor for cardiovascular disease, leads to increased all-cause mortality, and to increased liver-related mortality. This review focuses on recent advances in our understanding of the NAFLD disease spectrum, including etiology, diagnosis, treatment, and genetic and environmental risk factors and suggests future directions for research in this important area.

Contribution of metabolic factors to alanine aminotransferase activity in persons with other causes of liver disease

Role of Cholesterol in the Development and Progression of Breast Cancer

Breast cancer is the most common cancer among women, accounting for about 30% of all cancers. In contrast, breast cancer is a rare disease in men, accounting for less than 1% of all cancers. Up to 10% of all breast cancers are hereditary forms, caused by inherited germ-line mutations in “high-penetrance,” “moderate-penetrance,” and “low-penetrance” breast cancer susceptibility genes. The remaining 90% of breast cancers are due to acquired somatic genetic and epigenetic alterations. A heterogeneous set of somatic alterations, including mutations and gene amplification, are reported to be involved in the etiology of breast cancer. Promoter hypermethylation of genes involved in DNA repair and hormone-mediated cell signaling, as well as altered expression of micro RNAs predicted to regulate key breast cancer genes, play an equally important role as genetic factors in development of breast cancer. Elucidation of the inherited and acquired genetic and epigenetic alterations involved in breast cancer may not only clarify molecular pathways involved in the development and progression of breast cancer itself, but may also have an important clinical and therapeutic impact on improving the management of patients with the disease.

BackgroundIncreased collagen deposition provides physical and biochemical signals to support tumor growth and invasion during breast cancer development. Therefore, inhibition of collagen synthesis and deposition has been considered a strategy to suppress breast cancer progression. Collagen prolyl-4-hydroxylase α subunit 2 (P4HA2), an enzyme hydroxylating proline residues in -X-Pro-Gly- sequences, is a potential therapeutic target for the disorders associated with increased collagen deposition. However, expression and function of P4HA2 in breast cancer progression are not well investigated.MethodsGene co-expression analysis was performed in the published microarray datasets to identify potential regulators of collagen I, III, and IV in human breast cancer tissue. Expression of P4HA2 was silenced by shRNAs, and its activity was inhibited by 1, 4-DPCA, a prolyl-4-hydroxylase inhibitor. Three-dimensional culture assay was used to analyze roles of P4HA2 in regulating malignant phenotypes of breast cancer cells. Reduced deposition of collagen I and IV was detected by Western blotting and immunofluorescence. Control and P4HA2-silenced breast cancer cells were injected into fat pad and tail vein of SCID mice to examine effect of P4HA2 on tumor growth and lung metastasis.ResultsUsing gene co-expression analysis, we showed that P4HA2 was associated with expression of Col1A1, Col3A1, and Col4A1 during breast cancer development and progression. P4HA2 mRNA levels were significantly upregulated in breast cancer compared to normal mammary tissue. Increased mRNA levels of P4HA2 correlated with poor clinical outcome in breast cancer patients, which is independent of estrogen receptor status. Silencing P4HA2 expression or treatment with the P4HA inhibitor significantly inhibited cell proliferation and suppressed aggressive phenotypes of breast cancer cells in 3D culture, accompanied by reduced deposition of collagen I and IV. We also found that knockdown of P4HA2 inhibited mammary tumor growth and metastasis to lungs in xenograft models.ConclusionThese results suggest the critical role of P4HA2 in breast cancer progression and identify P4HA2 as a potential therapeutic target and biomarker for breast cancer progression.

Role of long-chain non-coding ribonucleic acid (lncRNA) GACAT1 in the development of breast cancer and its possible mechanism were investigated. The levels of GACAT1, microRNA-875-3p and Stonin2 (STON2) in breast cancer tissues and adjacent normal tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The level of GACAT1 in breast cancer cell lines was further explored. The effects of GACAT1 and microRNA-875-3p on cell proliferation and cycle were detected by cell counting kit-8 (CCK-8) and flow cytometry. The binding relationship between microRNA-875-3p and STON2, microRNA-875-3p and GACAT1 was examined by a dual luciferase reporting assay. It was confirmed by rescue experiments whether GACAT1 canregulate the level of STON2 by binding to microRNA-875-3p. GACAT1 level was clearly enhanced in breast cancer tissues compared to that of the adjacent tissues. Similar result was observed in breast cancer cell lines. Upregulation of GACAT1 promoted the proliferation and cycle of breast cancer cells including MCF-7 and BCap-37. The dual luciferase reporting assay results indicated that GACAT1 had a binding relationship with microRNA-875-3p. Further experiments confirmed that microRNA-875-3p was conspicuously downregulated in breast cancer tissues, and upregulation of microRNA-875-3p could inhibit the proliferation ability of MCF-7 and BCap-37 cells, and partially reversed the promoting effect of GACAT1 on cell cycle. Through bioinformatics prediction and dual luciferase reporter gene experiments, we found that STON2 might be a target gene of microRNA-875-3p. Overexpression of STON2 could partially abolish the effect of microRNA-875-3p on cell proliferation and cycle of MCF-7 and BCap-37 cells. GACAT1 can participate in the progression of breast cancer by promoting the proliferation and cycle of breast cancer cells. The mechanism may be through the regulation of the level of STON2 by adsorbing microRNA-875-3p.

Metastasis accounts for 90% of deaths in breast cancers patients. Therefore, the study of genetic factors regulating cancer malignancy is a top priority to mitigate the morbidity and mortality associated to this disease. One of these factors, Pax-5, normally regulates key biological functions such as cell viability, growth, and differentiation. However, an aberrant expression of this factor results in the development and progression of cancer. In this study, we developed breast cancer cell models with conditioned expression of the Pax-5 to evaluate signaling pathways relevant to breast metastasis and cancer progression. We found that Pax-5 extinguishes several aspects of cancer aggressivety such as: proliferation, spheroid formation, migration and invasion. At the molecular level, we found that Pax-5 modulates cancer malignancy through the regulation of various components of the epithelial to mesenchymal transitioning (EMT) process in addition to key signaling targets such as: NFκB and the Focal Adhesion Kinase 1 (FAK1). We also demonstrate that Pax-5 decreases FAK1 level trough up-regulation of miR-135b, a direct repressor of FAK1 expression. Altogether, our findings suggest that the presence of the Pax-5 lead to less aggressive breast cancers by promoting mesenchymal to Epithelial transitioning (MET). These findings bring light to molecular mechanisms driving breast cancer malignancy and benefit our quest in the development of diagnostic and therapeutic strategies against breast cancer progression. Citation Format: Sami Benzina, Pierre O'Brien, Annie-Pier Beauregard, Roxann Guérrette, Stéphanie Jean, Gilles Robichaud. Pax-5 regulates EMT and MET in breast cancer through FAK1 regulation [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-07-03.

Discovery of Centrosomal Protein 70 as an Important Player in the Development and Progression of Breast Cancer

Background:Abnormal metabolism, as measured by obesity, has been associated with an increase risk in both the development of breast cancer as well as breast cancer recurrence and death. To date, identification of a molecular link between obesity and breast cancer remains elusive. Farnesoid X receptor (FXR) is a ligand dependent transcriptional factor and plays a critical role in bile acid, cholesterol and carbohydrate metabolism. Little is known of the function of FXR in cancer although several recent studies have shown that FXR may contribute to breast, colorectal and hepatocellular cancer. Given the role of FXR in metabolism and emerging data suggesting a role for FXR in cancer, we hypothesize that expression of FXR in breast tissue may be related to metabolism. In addition, changes in FXR expression may also be associated with breast cancer development and progression.Methods:Clinical data on estrogen/progesterone receptor positive, Stage I and II breast cancer patients were extracted from an institutionally approved prospective database established in 2006. Paired formaldehyde fixed, paraffin embedded normal, in situ, and invasive tissues from these patients were identified from the COH tissue repository. Immunohistochemical staining of FXR using a validated polyclonal antibody was completed with appropriate positive and negative controls. The slides were graded independently by two investigators using an agreed upon scale to detect the percentage of positively stained cells to the nearest 10th percentile. Clinical data were correlated with expression analysis. Statistical analyses were performed with ANOVA tests followed by Fisher's t-tests for pair-wise comparisons. In determination of factors accounting for FXR expression, a multivariate analysis was completed. A p-value of 0.05 was considered significant in all analyses.Results:Paired normal tissue and invasive cancer was identified in all 43 patient specimens. In 40% (17/43) of these specimens, in situ disease was also identified. FXR expression in normal breast tissue was significantly less when compared to both invasive and noninvasive cancer (p≤ 0.001). The mean percentage of cells staining positive for FXR in normal breast tissue was 60%, non-invasive 77% and invasive 83% (p < 0.0001). FXR expression did not correlate with grade, histology, nodal status, Her 2 neu status, HTN, DM or hyperlipidemia in normal, in situ and invasive tissue on multivariate analysis. BMI strongly correlated with FXR expression in normal tissues (p = 0.02) and may correlate in in situ tissues (p = 0.07). However, there was no correlation of BMI with FXR expression in invasive cancer (p = 0.55).Conclusions:FXR expression is upregulated in invasive cancer and increases progressively along the continuum from normal breast tissue to malignancy. Expression of FXR correlates with BMI in normal breast tissue, suggesting that FXR may be a molecular link between obesity and the development and progression of breast cancer. Our results warrant further investigation into the relationship of FXR, obesity and breast cancer. These findings may provide support for the development of targeted FXR agents in prevention and treatment of obesity related cancers. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5153.

: Steroid hormones are involved in the development and growth of breast cancer. Drugs, which inhibit estrogen action, are commonly used to inhibit breast cancer growth. Unfortunately, most advanced breast cancer becomes resistant to estrogen treatment. Recently, many steroid receptor coactivators have been discovered and found to potentiate the transcriptional activity of steroid receptors and enhance the expression of hormone response genes. In the SRC-1 family of coactivators, AIB1 is found amplified and/or over-expressed in breast cancer specimens. To evaluate the potential roles of the SRC-1 family of coactivators in mammary tumorigenesis in vivo, we proposed to generate transgenic mice over-expression of AIB1 (SRC-3) in mammary glands. To target the expression of AIB1 in mammary gland, we placed the AIB1 transgene under the control of the MMTV-LTR promoter. Two lines of transgenic mice expressing AIB1 have been generated. Studies on these transgenic mice will help understand the development and progression of breast cancer and provide a molecular basis for designing novel strategies to curb and, ultimately, cure breast cancer.

A systematic study of posttranslational modifications of the estrogen receptor isolated from the MCF-7 human breast cancer cell line is reported. Proteolysis with multiple enzymes, mass spectrometry, and tandem mass spectrometry achieved very high sequence coverage for the full-length 66-kDa endogenous protein from estradiol-treated cell cultures. Nine phosphorylated serine residues were identified, three of which were previously unreported and none of which were previously observed by mass spectrometry by any other laboratory. Two additional modified serine residues were identified in recombinant protein, one previously reported but not observed here in endogenous protein and the other previously unknown. Although major emphasis was placed on identifying new phosphorylation sites, N-terminal loss of methionine accompanied by amino acetylation and a lysine side chain acetylation (or possibly trimethylation) were also detected. The use of both HPLC-ESI and MALDI interfaced to different mass analyzers gave higher sequence coverage and identified more sites than could be achieved by either method alone. The estrogen receptor is critical in the development and progression of breast cancer. One previously unreported phosphorylation site identified here was shown to be strongly dependent on estradiol, confirming its potential significance to breast cancer. Greater knowledge of this array of posttranslational modifications of estrogen receptor, particularly phosphorylation, will increase our understanding of the processes that lead to estradiol-induced activation of this protein and may aid the development of therapeutic strategies for management of hormone-dependent breast cancer.

Background: Slc26a9 (Solute carrier family 26 member 9) is a member of Slc26a family of multifunctional anion transporters, which functions as Cl- channel (Liu et al., Front Physiol 2018). Our previous study showed that SLC26A9 deficiency results in the development and progression of gastric cancer, which demonstrated that the key role of SLC26A9 in the tumorigenesis first time (Liu et al., Gastroenterology 2018). However, what’s the role of SLC26A9 in the breast cancer (BC) onset is not clear. We therefore wondered whether Slc26a9 gene is involved in promoting breast carcinogenesis and its mechanisms. Methods: The tissue microarrays and IHC assay were used to detect the expression and clinic relevance of SLC26A9 in the human BC. Different BC cell lines were used to investigate the expression and function of SLC26A9 in the BC. SLC26A9 gene transfect and knockout experiment were performed to detect the regulator role of SLC26A9 in BC cell behaviors. Results: Compared with adjacent normal tissues, SLC26A9 expression was significantly increased in the BC tissue, SLC26A9 expression level in BC correlated with the differentiated state of BC and patient’s clinical outcome, indicating that SLC26A9 may be involved in BC pathogenesis and progression in humans and it might be a novel poor prognosis marker for BC. Moreover, HER2 positive BC tissues exhibited high SLC26A9 expression than HER2 negative BC tissues. Compared with normal mammary cell line, SLC26A9 was significantly upregulated in the all BC cell lines, with highest expression in HER2 enriched cell line SKBR3. Deletion of SLC26A9 in SKBR3 resulted in inhibition of BC cell proliferation, migration and invasion, but promotion of cell apoptosis, which were investigated by different cell function assays, including cell counting Kit-8, cell proliferation curve, Annexin VFITC/PI double staining, Wound-healing and transwell assays respectively. Moreover, SLC26A9 deficiency in SKBR3 caused alteration of epithelial mesenchymal transition (EMT) markers, including downregulation of N-cadherin, Snail1, Fibronectin and Vimentin, but increasement of E-cadherin and ZO-1, accompany with disrupting TGFβ signaling pathways, including downregulation of TGF-β1, p-Smad2 and p-Smad3. However, overexpression of SLC26A9 in SKBR3 resulted in inhibition of cell proliferation, migration and invasion, but promotion of cell apoptosis. Accompanying with activation of TGFβ pathway mediate EMT. Conclusions: Upregulation of SLC26A9 resulted in the development and progression of HER2 positive BC via activation of TGFβ signaling pathways. SLC26A9 might be a novel prognosis marker and therapeutic target for BC. Citation Format: Zhiyuan Ma, Xuemei Liu, Chengli Lu, Jiaxing Zhu, Xiaoming Cheng, Biguang Tuo, Taolang Li. Upregulation of SLC26A9 resulted in the development and progression of HER2 positive breast cancer via activating TGFβ signaling pathway [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS19-27.