Molecular Differences between Squamous Cell Carcinoma and Adenocarcinoma Cervical Cancer Subtypes: Potential Prognostic Biomarkers

The most frequently diagnosed histological types of cervical cancer (CC) are squamous cell carcinoma (SCC) and adenocarcinoma (ADC). Clinically, the prognosis of both types is controversial. A molecular profile that distinguishes each histological subtype and predicts the prognosis would be of great benefit to CC patients. Methods: The transcriptome of CC patients from The Cancer Genome Atlas (TCGA) was analyzed using the DESeq2 package to obtain the differentially expressed genes (DEGs) between ADC and SCC. The DEGs were validated on a publicly available Mexican-Mestizo patient transcriptome dataset (GSE56303). The global biological pathways involving the DEGs were obtained using the Webgestalt platform. The associations of the DEGs with Overall Survival (OS) were assessed. Finally, three DEGs were validated by RT-qPCR in an independent cohort of Mexican patients. Results. The molecular profiles of ADC and SCC of the CC patients of the TCGA database and the Mexican-Mestizo cohort (GSE56303) were determined obtaining 1768 and 88 DEGs, respectively. Strikingly, 70 genes were concordant—with similar Log2FoldChange values—in both cohorts. The 70 DEGs were involved in IL-17, JAK/STAT, and Ras signaling. Kaplan-Meier OS analysis from the Mexican-Mestizo cohort showed that higher GABRB2 and TSPAN8 and lower TMEM40 expression were associated with better OS. Similar results were found in an independent Mexican cohort. Conclusions: Molecular differences were detected between the ADC and SCC subtypes; however, further studies are required to define the appropriate prognostic biomarker for each histological type.

LncRNAs driving feedback loops to boost drug resistance: sinuous pathways in cancer

Feedback loops mediate signaling pathways to maintain cellular homeostasis. There are two types, positive and negative feedback loops. Both are subject to alterations, and consequently can become pathogenic in the development of diseases such as cancer. Long noncoding RNAs (lncRNAs) are regulators of signaling pathways through feedback loops hidden as the dark regulatory elements yet to be described with great impact on cancer tumorigenesis, development, and drug resistance. Several feedback loops have been studied in cancer, however, how they are regulated by lncRNAs is hardly evident, setting a trending topic in oncological research. In this review, we recapitulate and discuss the feedback loops that are regulated by lncRNAs to promote drug resistance. Furthermore, we propose additional strategies that allow us to identify, analyze and comprehend feedback loops regulated by lncRNAs to induce drug resistance or even to gain insight into novel feedback loops that are stimulated under the pressure of treatment and consequently increase its efficacy. This knowledge will be useful to optimize the therapeutic use of oncological drugs.

Abstract PS16-35: Microbiota and breast cancer in mexican women

Microbiota and breast cancer in Mexican womenStudy Type: ObservationalTime Perspective: Cross-SectionalThe human microbiome refers to the genes of the universe of microbes that inhabit our skinand mucosal surfaces. Epidemiological studies implicated that human microfloracontributes to 16% more of malignant neoplasms worldwide, either as a risk factor orcausative agent.Although hereditary and genetic factors represent 5% to 10% of breast cancer cases, 70%of them are due to a host of environmental factors. Migrant studies demonstrated that non-hereditary factors are the main drivers of international and inter-ethnic differences in theincidence and mortality of breast cancer. The environment contributes to the developmentof the disease; although, the factors involved are not well known, among the latter is theinfluence of microorganisms and, therefore, attention is recently being paid to themammary microbiota. This study hypothesizes that women with breast cancer havedifferences in the composition and functionality of breast microbiota compared to womenwithout breast disease.Inclusion and exclusion criteria. Women's age range of 25-70 years. Women with confirmedbreast cancer diagnosis scheduled for surgery as primary treatment (mastectomy orconservative surgery) surgically intervened with breast augmentation or reduction withoutbreast cancer and signed informed consent. Women with antecedents of cancer, or whohave received antibiotic treatment one month before recruitment, or any neoadjuvanttherapy, without breast surgery in the past for any reason. Immunocompromised patients.Pregnant patients or with the use of implants were excluded from the study.Sample size. Sixty women with confirmed breast cancer matched with 30 women withoutcancer, and 30 with benign breast disease. Three hospitals participated in the recruitment:Instituto Nacional de Cancerología, Centro Oncológico Estatal ISSEMYM and Centromedico ABC.Method: DNA total of tissue samples was extracted using the Quick-DNA Miniprep Plus Kit(Zymo research Cat. D4068). 5 uL of DNA isolated of tissue samples were amplified with16S™ Metagenomics Kit (Thermo Fisher Scientific, Cat. A26216) and were marked with IonXpress Barcode Adapter (Thermo Fisher Scientific cat. no. 4471250), purified with AMPureXP reagent (Beckman Coulter cat. no. A63881) and quantified with Ion Universal LibraryQuantitation Kit (Thermo Fisher Scientific cat. no. A26217). After that, emulsion PCR wasprepared in the Ion OneTouch 2 System (Thermo Fisher Scientific). For sequencing, we usedthe Ion PGM Hi-Q view Sequencing kit (REFA30044) with chips 318 in the Ion torrent PGMinstrument (Thermo Fisher Scientific).

Results: In this study, we employed 16s rRNA sequencing to analyze the bacterial profiles ofnormal, benign, and breast tumor tissues. We observed that the beta diversity between thethree types of tissues is similar, although patients showed significant differences in theabundance of specific bacteria genera depending on the tissue of origin. We determinedthat bacteria from the genera Burkholderia had a lower relative abundance in benign tissuesthan normal tissues, although these genera had a higher relative abundance in tumortissues. We found a more significant difference in the amount of bacteria between benignand tumoral tissues; we observed that the seven genera (Aeromonas, Alcanivorax, Burkholderia, Corynebacterium, Finegoldia, Pseudomonas and Staphylococcus) are greaterintumortissueswhereasfivegenera: Cupriavidus, Microbacterium, Ralstonia, Renibacterium and Sphingomonas had alower relative abundance in tumoral tissues. This study suggests that bacterial beta-diversity does not change much among the analyzed tissues; however, it is specific bacterialgenera that change their relative abundance during tumor progression.

Citation Format: Arely Berenice González Valdés, Juan Enrique Bargallo Rocha, Juan Manuel Medina Castro, Carlos Pérez Plasencia, Oliver Millan Catalan, Elvia Fernández Pérez, Antonio Daniel Martinez, David Cantú De León. Microbiota and breast cancer in mexican women [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 PS16-35.

miRNA profile obtained by next‑generation sequencing in metastatic breast cancer patients is able to predict the response to systemic treatments

Metastatic breast cancer (MBC) is a challenge for oncologists, and public efforts should focus on identifying additional molecular markers and therapeutic management to improve clinical outcomes. Among all diagnosed cases of breast cancer (BC; approximately 10%) involve metastatic disease; notably, approximately 40% of patients with early-stage BC develop metastasis within 5 years. The management of MBC consists of systemic therapy. Despite different treatment options, the 5-year survival rate is <20%, which may be due to a lack of response with de novo or acquired resistance. MicroRNAs (miRNAs or miRs) are promising biomarkers as they are readily detectable and have a broad spectrum and potential clinical applications. The aim of this study was to identify a miRNA profile for distinguishing patients with MBC who respond to systemic treatment. Patients with MBC were treated according to the National Comprehensive Cancer Network guidelines. We performed miRNA-Seq on 9 primary tumors using the Thermo Fisher Scientific Ion S5 system. To obtain global miRNA profiles, we carried out differentially expressed gene elimination strategy (DEGES) analysis between the responsive and non-responsive patients. The results identified a profile of 12 miRNAs associated with the response to systemic treatment. The data were validated in an independent cohort (TCGA database). Based on the results, the upregulation of miR-342-3p and miR-187-3p was associated with the response to systemic treatment, and with an increased progression-free survival (PFS) and overall survival (OS); by contrast, the downregulation of miR-301a-3p was associated with a higher PFS and OS. On the whole, the findings of this study indicate that these miRNAs may serve as biomarkers for the response to systemic treatment or the prognosis of patients with MBC. However, these data should be validated experimentally in other robust cohorts and using different specimens before implementing these miRNAs as biomarkers in clinical practice to benefit this group of patients.

Characterization of cervical cancer stem cell-like cells: phenotyping, stemness, and human papilloma virus co-receptor expression

Cancer stem cells (CSC) exhibit high tumorigenic capacity in several tumor models. We have now determined an extended phenotype for cervical cancer stem cells. Our results showed increased CK-17, p63+, AII+, CD49f+ expression in these cells, together with higher Aldehyde dehydrogenase (ALDHbright)activity in Cervical CSC (CCSC) enriched in cervospheres. An increase in stem cell markers, represented by OCT-4, Nanog, and β-catenin proteins, was also observed, indicating that under our culture conditions, CCSC are enriched in cervospheres, as compared to monolayer cultures. In addition, we were able to show that an increased ALDHbright activity correlated with higher tumorigenic activity. Flow cytometry and immunflorescence assays demonstrated that CCSC in cervosphere cultures contain a sub-population of cells that contain Annexin II, a Human papillomavirus (HPV) co-receptor. Taken together, under our conditions there is an increase in the number of CCSC in cervosphere cultures which exhibit the following phenotype: CK-17, p63+, AII+, CD49f+ and high ALDH activity, which in turn correlates with higher tumorigenicity. The presence of Annexin II and CD49f in CCSC opens the possibility that normal cervical stem cells could be the initial target of infection by high risk HPV.

Unusual case of subcutaneous angiosarcoma metastatic to the ovary

The ovaries are common sites for metastatic disease, however, the most frequent ones are carcinomas. Metastatic sarcomas are very rare in ovary and most of them arise from genital tract. We present the case of a 33-year-old woman with subcutaneous angiosarcoma who had metastatic disease to the ovary resulting in acute abdominal pain. Discussion of the case and a review of the literature are presented.