Leptin and its receptor are overexpressed in breast cancer tissue of postmenopausal Mexican-Mestizo women with obesity.

The aim of this study was to investigate the expression of leptin (LEP) and its receptor (LEPR) in breast cancer tissue of postmenopausal women with different body mass indexes (BMI), as well as the relationship of this expression with the rate of recurrence free survival (RFS). Leptin and LEPR expression, determined by immunohistochemistry, were studied in breast cancer tissues of 154 patients. Qualitative and semi-quantitative analysis of protein expression was performed by the H-Score method, through the ImageJ's IHC Profiler software. Kaplan-Meier survival analysis and log-rank statistic were used to estimate RFS differences. Protein expression of LEP, was significantly higher in women with overweight or with obesity, when compared to women with normal BMI (P = 0.032 and P = 0.013, respectively). We also observed a significantly higher expression of LEPR in breast tumor cells of women with obesity (58.8%), when compared to women with normal BMI (32.7%) (P = 0.007). Five-year survival rate, regarding LEPR expression, was 82.4% when positive and 94% when negative (P = 0.024). In the Cox proportional-hazards regression model, LEPR expression represented a risk factor for disease recurrence after adjustment for confounding factors (HR = 4.67; 95% CI: 1.13-19.31; P = 0.033). In conclusion, postmenopausal women with obesity and breast cancer present higher LEP and LEPR expression in breast tumors, when compared to women with normal BMI. Independently from BMI, women with tumors LEPR positive have worst RFS, when compared to women with tumors LEPR negative.

Comprehensive omic characterization of breast cancer in Mexican-Hispanic women.

Breast cancer is a heterogeneous pathology, but the genomic basis of its variability remains poorly understood in populations other than Caucasians. Here, through DNA and RNA portraits we explored the molecular features of breast cancers in a set of Hispanic-Mexican (HM) women and compared them to public multi-ancestry datasets. HM patients present an earlier onset of the disease, particularly in aggressive clinical subtypes, compared to non-Hispanic women. The age-related COSMIC signature 1 was more frequent in HM women than in those from other ancestries. We found the AKT1E17K hotspot mutation in 8% of the HM women and identify the AKT1/PIK3CA axis as a potentially druggable target. Also, HM luminal breast tumors present an enhanced immunogenic phenotype compared to Asiatic and Caucasian tumors. This study is an initial effort to include patients from Hispanic populations in the research of breast cancer etiology and biology to further understand breast cancer disparities.

Different body mass indexes and their relation to prognosis of early-stage breast cancer in postmenopausal Mexican-Mestizo women.

It has been suggested that obesity increases the incidence of metastatic breast tumors, resulting in higher rates of recurrence, and increased mortality; for that reason, the aim of this study was to investigate if different body mass indexes modified the clinicopathologic characteristics of breast cancer; as well as, the recurrence-free survival in postmenopausal Mexican-Mestizo women. Two hundred twenty postmenopausal women with operable breast cancer were included. A structured questionnaire was applied to explore the existence of potential risk factors. Body mass index (BMI) was determined in each case and patients were grouped in accordance to their BMI in: normal weight, overweight, or obesity. Kaplan-Meier survival analysis and log-rank statistic were used to estimate recurrence-free-survival differences. Hormonal receptor(+)/HER2(-) was the most frequent breast cancer in all groups. Overweight women presented a statistically significant increased risk of this molecular subtype, with an odds ratio (OR) = 5.57; 95% confidence interval (CI) = 1.54-24.86; P = .004)). In addition, the triple-negative subtype was more frequent in women with a normal BMI in comparison to women with overweight (P = .016) or women with obesity. The heterogeneity in cancer subtypes regarding BMI was observed.

Adiponectin and adiponectin receptor 1 expression proteins levels are modified in breast cancer in postmenopausal women with obesity.

AIM: To analyse the expression of adiponectin (ADIPOQ), and its receptors ADIPOR1 and ADIPOR2, in breast cancer tissue of postmenopausal women with different body mass indexes (BMIs). SUBJECTS AND METHODS: One hundred and fifty postmenopausal Mexican-Mestizo women with breast cancer were included. BMI was determined in each case. To carry out qualitative and semiquantitative assessments of protein expression by immunohistochemistry, the H-Score method was used, through ImageJ's IHC Profiler software. Statistical power of the study was >80% with a p<0.05. RESULTS: Fifty women had a normal BMI, 50 presented overweight and 50 had obesity. The expression of ADIPOQ in breast cancer tissue of postmenopausal woman with normal BMI was higher in comparison to women with overweight or with obesity (p=0.002 and p<0.001, respectively). Furthermore, the expression of ADIPOR1 in breast cancer tissue of postmenopausal women with normal BMI was significantly lower when compared with women with overweight or with obesity (p=0.005 and p<0.001, respectively). Meanwhile, the expression of ADIPOR2 in breast cancer tissue, in the cytoplasm, was similar in all groups studied. CONCLUSIONS: We found that women with overweight or obesity had a lower expression of ADIPOQ and a higher ADIPOR1 expression in breast cancer tissue, when compared with women with a normal BMI.

Mitochondrial DNA Mutation Analysis in Breast Cancer: Shifting From Germline Heteroplasmy Toward Homoplasmy in Tumors.

Studies have suggested a potential role of somatic mitochondrial mutations in cancer development. To analyze the landscape of somatic mitochondrial mutation in breast cancer and to determine whether mitochondrial DNA (mtDNA) mutational burden is correlated with overall survival (OS), we sequenced whole mtDNA from 92 matched-paired primary breast tumors and peripheral blood. A total of 324 germline variants and 173 somatic mutations were found in the tumors. The most common germline allele was 663G (12S), showing lower heteroplasmy levels in peripheral blood lymphocytes than in their matched tumors, even reaching homoplasmic status in several cases. The heteroplasmy load was higher in tumors than in their paired normal tissues. Somatic mtDNA mutations were found in 73.9% of breast tumors; 59% of these mutations were located in the coding region (66.7% non-synonymous and 33.3% synonymous). Although the CO1 gene presented the highest number of mutations, tRNA genes (T,C, and W), rRNA 12S, and CO1 and ATP6 exhibited the highest mutation rates. No specific mtDNA mutational profile was associated with molecular subtypes of breast cancer, and we found no correlation between mtDNA mutational burden and OS. Future investigations will provide insight into the molecular mechanisms through which mtDNA mutations and heteroplasmy shifting contribute to breast cancer development.

FAM83H-AS1 is a potential modulator of cancer driver genes across different tumors and a prognostic marker for ER/PR + BRCA patients.

Breast cancer (BRCA) is a serious public health problem, as it is the most frequent malignant tumor in women worldwide. BRCA is a molecularly heterogenic disease, particularly at gene expression (mRNAs) level. Recent evidence shows that coding RNAs represent only 34% of the total transcriptome in a human cell. The rest of the 66% of RNAs are non-coding, so we might be missing relevant biological, clinical or regulatory information. In this report, we identified nine novel tumor types from TCGA with FAM83H-AS1 deregulation. We used survival analysis to demonstrate that FAM83H-AS1 expression is a marker for poor survival in IHC-detected ER and PR positive BRCA patients and found a significant correlation between FAM83H-AS1 overexpression and tamoxifen resistance. Estrogen and Progesterone receptor expression levels interact with FAM83H-AS1 to potentiate its effect in OS prediction. FAM83H-AS1 silencing impairs two important breast cancer related pathways: cell migration and cell death. Among the most relevant potential FAM83H-AS1 gene targets, we found p63 and claudin 1 (CLDN1) to be deregulated after FAM83H-AS1 knockdown. Using correlation analysis, we show that FAM83H-AS1 can regulate a plethora of cancer-related genes across multiple tumor types, including BRCA. This evidence suggests that FAM83H-AS1 is a master regulator in different cancer types, and BRCA in particular.

A lncRNA landscape in breast cancer reveals a potential role for AC009283.1 in proliferation and apoptosis in HER2-enriched subtype.

Breast cancer is the most commonly diagnosed neoplasm in women worldwide with a well-recognized heterogeneous pathology, classified into four molecular subtypes: Luminal A, Luminal B, HER2-enriched and Basal-like, each one with different biological and clinical characteristics. Long non-coding RNAs (lncRNAs) represent 33% of the human transcriptome and play critical roles in breast carcinogenesis, but most of their functions are still unknown. Therefore, cancer research could benefit from continued exploration into the biology of lncRNAs in this neoplasm. We characterized lncRNA expression portraits in 74 breast tumors belonging to the four molecular subtypes using transcriptome microarrays. To infer the biological role of the deregulated lncRNAs in the molecular subtypes, we performed co-expression analysis of lncRNA-mRNA and gene ontology analysis. We identified 307 deregulated lncRNAs in tumor compared to normal tissue and 354 deregulated lncRNAs among the different molecular subtypes. Through co-expression analysis between lncRNAs and protein-coding genes, along with gene enrichment analysis, we inferred the potential function of the most deregulated lncRNAs in each molecular subtype, and independently validated our results taking advantage of TCGA data. Overexpression of the AC009283.1 was observed in the HER2-enriched subtype and it is localized in an amplification zone at chromosome 17q12, suggesting it to be a potential tumorigenic lncRNA. The functional role of lncRNA AC009283.1 was examined through loss of function assays in vitro and determining its impact on global gene expression. These studies revealed that AC009283.1 regulates genes involved in proliferation, cell cycle and apoptosis in a HER2 cellular model. We further confirmed these findings through ssGSEA and CEMITool analysis in an independent HER2-amplified breast cancer cohort. Our findings suggest a wide range of biological functions for lncRNAs in each breast cancer molecular subtype and provide a basis for their biological and functional study, as was conducted for AC009283.1, showing it to be a potential regulator of proliferation and apoptosis in the HER2-enriched subtype.

Expression of long non-coding RNA ENSG00000226738 (LncKLHDC7B) is enriched in the immunomodulatory triple-negative breast cancer subtype and its alteration promotes cell migration, invasion, and resistance to cell death.

Triple negative breast cancer (TNBC) represents an aggressive phenotype with poor prognosis compared with ER, PR, and HER2-positive tumors. TNBC is a heterogeneous disease, and gene expression analysis has identified seven molecular subtypes. Accumulating evidence demonstrates that long non-coding RNA (lncRNA) are involved in regulation of gene expression and cancer biology, contributing to essential cancer cell functions. In this study, we analyzed the expression profile of lncRNA in TNBC subtypes from 156 TNBC samples, and then characterized the functional role of LncKLHDC7B (ENSG00000226738). A total of 710 lncRNA were found to be differentially expressed between TNBC subtypes, and a subset of these altered lncRNA were independently validated. We discovered that LncKLHDC7B (ENSG00000226738) acts as a transcriptional modulator of its neighboring coding gene KLHDC7B in the immunomodulatory subtype. Furthermore, LncKLHDC7B knockdown enhanced migration and invasion, and promoted resistance to cellular death. Our findings confirmed the contribution of LncKLHDC7B to induction of apoptosis and inhibition of cell migration and invasion, suggesting that TNBC tumors with enrichment of LncKLHDC7B may exhibit distinct regulatory activity, or that this may be a generalized process in breast cancer. Additionally, in silico analysis confirmed for the first time that the low expression of KLHDC7B and LncKLHDC7B is associated with poor prognosis in patients with breast cancer.