Implications of tumor-infiltrating lymphocytes in early-stage triple-negative breast cancer: clinical oncologist perspectives.

Breast cancer (BC) is the most common neoplasm in women worldwide and one of the leading causes of female death. The triple-negative subtype, characterized by the absence of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2), tends to occur in younger patients, be more aggressive and less differentiated. Furthermore, this subtype is considered the most immunogenic and associated with higher levels of tumor cell infiltration, mainly lymphocytes. Tumor-infiltrating lymphocytes (TILs) play a crucial role in the interaction of the host's immune system and cancer cells. The microenvironment is critical in tumor development and progression. Assessment of infiltrating lymphocytes can provide valuable information about the immune response and, given the lack of biomarkers to guide treatment decisions and predict outcomes in triple-negative tumors and can be considered as a potential biomarker. Some evidence suggests that higher levels of these lymphocytes are associated with better responses to systemic treatment, longer progression-free survival and overall survival (OS). However, treatment escalation or de-escalation strategies for triple-negative BC (TNBC) currently do not consider the presence or density of TILs for therapeutic decisions. TILs appear to be useful predictive and prognostic indicators. Further clinical studies are needed to confirm these relationships and integrate TILs as a biomarker consistently into clinical practice. This article summarizes key concepts relating to the role of the immune infiltrate in BC, along with the current status and future prospects regarding TILs as a predictive and prognostic biomarker.

Antineoplastic effect of compounds C14 and P8 on TNBC and radioresistant TNBC cells by stabilizing the K-Ras4BG13D/PDE6δ complex.

Introduction: Breast cancer (BC) is the leading cause of cancer-related deaths among women, with triple-negative breast cancer (TNBC) representing one of the most aggressive and treatment-resistant subtypes. In this study, we aimed to evaluate the antitumor potential of C14 and P8 molecules in both TNBC and radioresistant TNBC cells. These compounds were chosen for their ability to stabilize the complex formed by the overactivated form of K-Ras4BG13D and its membrane transporter (PDE6δ). Methods: The antitumor potential of C14 and P8 was assessed using TNBC cell lines, MDA-MB-231, and the radioresistant derivative MDA-MB-231RR, both carrying the K-Ras4B> G13D mutation. We investigated the compounds' effects on K-Ras signaling pathways, cell viability, and tumor growth in vivo. Results: Western blotting analysis determined the negative impact of C14 and P8 on the activation of mutant K-Ras signaling pathways in MDA-MB-231 and MDA-MB-231RR cells. Proliferation assays demonstrated their efficacy as cytotoxic agents against K-RasG13D mutant cancer cells and in inducing apoptosis. Clonogenic assays proven their ability to inhibit TNBC and radioresistant TNBC cell clonogenicity. In In vivo studies, C14 and P8 inhibited tumor growth and reduced proliferation, angiogenesis, and cell cycle progression markers. Discussion: These findings suggest that C14 and P8 could serve as promising adjuvant treatments for TNBC, particularly for non-responders to standard therapies. By targeting overactivated K-Ras and its membrane transporter, these compounds offer potential therapeutic benefits against TNBC, including its radioresistant form. Further research and clinical trials are warranted to validate their efficacy and safety as novel TNBC treatments.

Assessment of TUFT1 and Rac1-GTP levels in triple-negative breast cancer patients: clinical and pathological correlations.

OBJECTIVE: The primary goal of this study was to investigate the expressions of TUFT1 (Tuftelin) and Rac1-GTP in the cancerous tissues of individuals with triple-negative breast cancer (TNBC). Additionally, we aimed to explore the correlation between TUFT1 and Rac1-GTP expressions and examine the associations of TUFT1 and Rac1-GTP expressions with the clinical and pathological indicators of the patients. METHODS: Ninety-six patients diagnosed with TNBC, scheduled for surgery between May 2022 and November 2022, were enrolled in this study. Cancerous tissue specimens were collected from these patients, and immunohistochemistry was employed to evaluate the levels of TUFT1 and Rac1-GTP expressions in the cancerous tissues. Subsequent to data collection, a comprehensive analysis was conducted to examine the correlation between TUFT1 and Rac1-GTP expressions. Furthermore, we sought to assess the associations of TUFT1 and Rac1-GTP expressions with the clinical and pathological indicators of the patients. RESULTS: The TUFT1 protein was expressed in both the membrane and cytoplasm of TNBC cancer cells, with notably higher expression observed in the cytoplasm. Rac1-GTP was primarily expressed in the cytoplasm. There was a positive correlation between the levels of TUFT1 and Rac1-GTP expressions (χ2 = 9.816, P < 0.05). The levels of TUFT1 and Rac1-GTP protein expressions showed no correlation with patient age (χ2 = 2.590, 2.565, P > 0.05); however, they demonstrated a positive correlation with tumor size (χ2 = 5.592,5.118), histological grading (χ2 = 6.730, 5.443), and lymph node metastasis (χ2 = 8.221, 5.180) (all with a significance level of P < 0.05). CONCLUSION: A significant correlation was identified between the levels of TUFT1 and Rac1-GTP expressions in the cancerous tissues of patients with TNBC, suggesting a close association with the progression of TNBC. The two molecules play significant roles in facilitating an early diagnosis and treatment of TNBC.

α-Mangostin induces oxidative damage, mitochondrial dysfunction, and apoptosis in a triple-negative breast cancer model.

Triple-negative breast cancer (TNBC) does not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor; therefore, TNBC lacks targeted therapy, and chemotherapy is the only available treatment for this illness but causes side effects. A putative strategy for the treatment of TNBC could be the use of the polyphenols such as α-Mangostin (α-M), which has shown anticancerogenic effects in different cancer models and can modulate the inflammatory and prooxidant state in several pathological models. The redox state, oxidative stress (OS), and oxidative damage are highly related to cancer development and its treatment. Thus, this study aimed to evaluate the effects of α-M on redox state, mitochondrial metabolism, and apoptosis in 4T1 mammary carcinoma cells. We found that α-M decreases both protein levels and enzymatic activity of catalase, and increases reactive oxygen species, oxidized proteins and glutathione disulfide, which demonstrates that α-M induces oxidative damage. We also found that α-M promotes mitochondrial dysfunction by abating basal respiration, the respiration ligated to oxidative phosphorylation (OXPHOS), and the rate control of whole 4T1 cells. Additionally, α-M also decreases the levels of OXPHOS subunits of mitochondrial complexes I, II, III, and adenosine triphosphate synthase, the activity of mitochondrial complex I as well as the levels of peroxisome proliferator-activated receptor-gamma co-activator 1α, showing a mitochondrial mass reduction. Then, oxidative damage and mitochondrial dysfunction induced by α-M induce apoptosis of 4T1 cells, which is evidenced by B cell lymphoma 2 decrease and caspase 3 cleavage. Taken together, our results suggest that α-M induces OS and mitochondrial dysfunction, resulting in 4T1 cell death through apoptotic mechanisms.

Unveiling the vulnerabilities of synthetic lethality in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most invasive molecular subtype of breast cancer (BC), accounting for about nearly 15% of all BC cases reported annually. The absence of the three major BC hormone receptors, Estrogen (ER), Progesterone (PR), and Human Epidermal Growth Factor 2 (HER2) receptor, accounts for the characteristic "Triple negative" phraseology. The absence of these marked receptors makes this cancer insensitive to classical endocrine therapeutic approaches. Hence, the available treatment options remain solemnly limited to only conventional realms of chemotherapy and radiation therapy. Moreover, these therapeutic regimes are often accompanied by numerous treatment side-effects that account for early distant metastasis, relapse, and shorter overall survival in TNBC patients. The rigorous ongoing research in the field of clinical oncology has identified certain gene-based selective tumor-targeting susceptibilities, which are known to account for the molecular fallacies and mutation-based genetic alterations that develop the progression of TNBC. One such promising approach is synthetic lethality, which identifies novel drug targets of cancer, from undruggable oncogenes or tumor-suppressor genes, which cannot be otherwise clasped by the conventional approaches of mutational analysis. Herein, a holistic scientific review is presented, to undermine the mechanisms of synthetic lethal (SL) interactions in TNBC, the epigenetic crosstalks encountered, the role of Poly (ADP-ribose) polymerase inhibitors (PARPi) in inducing SL interactions, and the limitations faced by the lethal interactors. Thus, the future predicament of synthetic lethal interactions in the advancement of modern translational TNBC research is assessed with specific emphasis on patient-specific personalized medicine.

Caracterização funcional do gene codificador de proteína CD14 e do gene não codificador de proteína LINC01133 em linhagens celulares humanas de câncer de mama triplo negativo / Functional characterization of the CD14 protein-coding gene and the non-protein-coding LINC01133 gene in triple negative human breast cancer cell lines

Dentre os subtipos de câncer de mama, o triplo negativo (TNBC) é o que apresenta as maiores taxas de mortalidade, sendo, portanto, considerado um enorme desafio para a clínica. O uso de moléculas como marcadores tumorais vem auxiliando o clínico no diagnóstico, no prognóstico e, até mesmo, no tratamento do TNBC, sendo essenciais na redução de suas altas taxa de mortalidade. No entanto, um pequeno grupo de marcadores tumorais são validados na prática clínica, estimulando à busca por novos alvos, e sua caracterização funcional, como forma de se entender a Biologia desta doença. Assim, o objetivo deste trabalho é caracterizar funcionalmente o gene codificador de proteína CD14 e o gene não codificador de proteína LINC01133 em linhagens celulares humanas de TNBC, no intuito de descobrir o papel destas moléculas na progressão tumoral. Na primeira parte deste trabalho, analisou-se a expressão do CD14 frente à um painel de linhagens celulares que representam os diferentes subtipos dos tumores mamários. O CD14 exibiu elevados níveis de expressão nas linhagens nãotumorigênicas MCF10A e MCF12A e baixos níveis na linhagem triplo negativa Hs578T. A partir destes resultados, o CD14 foi superexpresso na linhagem Hs578T. Ensaios de caracterização funcional mostraram que a superexpressão do CD14 reduziu a capacidade migratória e invasiva das células, efeito que foi hipoteticamente relacionado ao aumento da expressão da E-caderina. No entanto, observou-se aumento no potencial tumorigênico, levando-nos a sugerir seu envolvimento num possível mecanismo utilizado pelas células para compensar a significativa redução do potencial migratório e invasivo. Os resultados obtidos indicam que o nível basal de expressão do CD14 observado na linhagem Hs578T é importante, podendo contribuir para a desenvolvimento primário do tumor, atuando como um oncogene. Na segunda parte deste trabalho, analisou-se a expressão de 10 RNAs longos não codificadores (lncRNAs), frente ao mesmo painel de linhagens descritoanteriormente. Dentre estes, o lncRNA LINC01133 exibiu baixos níveis de expressão nas linhagens não-tumorigênicas MCF10A e MCF12A e elevados níveis na linhagem triplo negativa Hs578T, sendo, então, escolhido como alvo de estudo. A partir destes resultados, decidimos superexpressar, de forma indutível, o LINC01133 na linhagem MCF10A e nocautear este gene, via sistema CRISPR/Cas9, na linhagem Hs578T. Ensaios de caracterização funcional mostraram que a superexpressão do LINC01133 na linhagem MCF10A reduziu a proliferação celular e inibiu o crescimento de colônias dependente de ancoragem, mas, em contrapartida, aumentou o crescimento de colônias independente de ancoragem e a capacidade migratória e invasiva destas células. No entanto, sugerimos que isto não seja suficiente para tornar estas células tumorigênicas e metastáticas. Por outro lado, o nocauteamento do LINC01133 na linhagem triplo negativa Hs578T aumentou de forma considerável todos os parâmetros de malignidade analisados. Baseado nos dados obtidos, sugerimos que o elevado nível de expressão do LINC01133 na linhagem Hs578T é importante na regulação negativa de processos relacionados com a progressão tumoral, atuando com um supressor tumoral. Os dados obtidos em nosso estudo contribuem para o enriquecimento de informações relacionadas à Biologia do TNBC, auxiliando, desta forma, no desenvolvimento de potenciais protocolos clínicos e terapêuticos utilizandos estes biomarcadores

Among the breast cancer subtypes, the triple negative (TNBC) displays the highest mortality rates, being, therefore, considered a major challenge for the clinic. The use of molecules as tumor markers has helped clinicians in the diagnosis, prognosis and even in treatment of TNBC, being essential in reducing its high mortality rate. However, a small group of tumor markers is validated in clinical practice, stimulating the search for new targets, and their functional characterization, as a way to understand the biology of this disease. Thus, the aim of this work is to functionally characterize the CD14 protein-coding gene and the non-protein-coding LINC01133 gene in human TNBC cell lines, in order to probe into the role of these molecules in tumor progression. In the first part of this work, the expression of CD14 was analyzed in a panel of cell lines that represent the different subtypes of breast tumors. High expression levels of CD14 were observed in the non-tumorigenic MCF10A and MCF12A lineages and low levels in the triple negative Hs578T lineage. Based on these results, CD14 was overexpressed in the Hs578T lineage. Functional characterization assays showed that CD14 overexpression reduced the migratory and invasive capacity of cells, an effect that was hypothetically related to increased E-cadherin expression. However, increased in the tumorigenic potential was observed, leading us to suggest its involvement in a possible mechanism used by cells to compensate for the significant reduction in the migratory and invasive potential. The results obtained indicate that CD14 expression basal level observed in the Hs578T lineage may be important to contribute to the primary development of tumor, thus acting as an oncogene. In the second part of this work, the expression of 10 long non-coding RNAs (lncRNAs) was analyzed against the same lineage panel described above. Among these, the LINC01133 lncRNA exhibited low expression levels in the non-tumorigenic MCF10A and MCF12A lineages and high levels in the triple negative Hs578T lineage, being, then, chosen as a target for this study. Based on these results, we decided toinducibly overexpress LINC01133 in the MCF10A lineage and knockout this gene, via the CRISPR/Cas9 system, in the Hs578T lineage. Functional characterization assays showed that overexpression of LINC01133 in the MCF10A lineage reduced cell proliferation and inhibited anchorage-dependent colony growth, but, on the other hand, increased anchorage-independent colony growth and the migratory and invasive capacity of these cells. However, we suggest that this is not sufficient to render these cells tumorigenic and metastatic. On the other hand, the knockout of LINC01133 in the triple negative Hs578T lineage considerably increased all the analyzed malignancy parameters. Based on the results obtained, we suggest that the high expression level of LINC01133 in the Hs578T lineage is important for down-regulation of processes related to tumor progression, acting as a tumor suppressor. The data obtained in our study contribute to the enrichment of information related to TNBC Biology, thus assisting in the development of potential clinical and therapeutic protocols using these biomarkers

High triple-negative breast cancer prevalence and aggressive prognostic factors in Barbadian women with breast cancer.

BACKGROUND: Women of African ancestry (WAA) are disproportionately affected by triple-negative breast cancer (TNBC), which remains one of the most clinically challenging breast cancer (BCa) subtypes. This study investigated the prevalence of TNBC and epidemiological trends for BCa in Barbados, a Caribbean island with a high percentage of African ancestry. METHODS: Pathology reports for all BCa cases between 2007 and 2016 were collected from the sole hospital in Barbados and reviewed. The clinicopathological data collected included age, tumor grade, lymph node status, and hormone receptor status as determined by immunohistochemistry. BCa data for non-Hispanic white (NHW) and non-Hispanic black (NHB) American populations were accessed from the Surveillance, Epidemiology, and End Results database. RESULTS: There were 1997 BCa cases in Barbados between 2007 and 2016 for an estimated incidence rate of 135.1 per 100,000 women in Barbados (standardized to the US population, where the standardized incidence rates for NHBs and NHWs were 141.4 and 152.6 per 100,000, respectively). Age-specific incidence rates in Barbados for this period were consistently higher in younger age groups (15-59 years) in comparison with NHWs and NHBs. Between 2010 and 2016 in Barbados, a TNBC prevalence of 25% was observed, whereas TNBC prevalences of 21% and 10% were observed in NHBs and NHWs, respectively. CONCLUSIONS: The BCa incidence was higher in younger Barbadian women than NHWs and NHBs, and the TNBC prevalence was ~2.5 times higher than the prevalence in NHWs. This hints at a possible genetic predisposition and other socioeconomic factors that could explain the high TNBC prevalence and aggressive clinical course in WAA globally.

Avelumab, an IgG1 anti-PD-L1 Immune Checkpoint Inhibitor, Triggers NK Cell-Mediated Cytotoxicity and Cytokine Production Against Triple Negative Breast Cancer Cells.

The standard treatment for Triple Negative Breast Cancer (TNBC) patients is cytotoxic chemotherapy, but it is restricted since the duration of response is usually short. Blocking the PD-1/PD-L1 pathway through monoclonal antibodies (mAbs) appears to be a promising therapeutic strategy for TNBC patients. Avelumab is a human IgG1 anti-PD-L1 mAb being tested in clinical trials that may also trigger antibody-dependent cell-mediated cytotoxicity (ADCC) against cancer cells as an additional antitumor activity. In the present work, we studied in vitro Avelumab-mediated ADCC against a panel of TNBC cells with different PD-L1 expression using peripheral blood mononuclear cells (PBMC) or purified NK cells from healthy donors. We determined that Avelumab significantly enhanced NK-cell mediated cytotoxicity against TNBC cells and that tumor cells expressing higher levels of PD-L1 were more sensitive to Avelumab-mediated ADCC. IFN-γ treatment upregulated PD-L1 expression in tumor cells but had a variable impact on Avelumab-mediated ADCC, which could be related to the simultaneous effect of IFN-γ on the expression of NK cell ligands. Moreover, IL-2 and IL-15 stimulation of NK cells enhanced Avelumab-triggered cytokine production and degranulation along with increased lytic activity against tumor cells. Improving the treatment of TNBC remains still a considerable challenge. This in vitro study suggests that Avelumab-mediated ADCC, independently of the blockade of the PD-1/PD-L1 pathway, could be a valuable mechanism for tumor cell elimination in TNBC. Avelumab combination with immunomodulators such as IL-15 or IL-2 could be taken into consideration to increase the therapeutic efficacy of Avelumab in TNBC.

Receptor de Andrógenos y Cáncer de Mama Triple Negativo: implicaciones clínicas y correlación con factores pronósticos y predictivos / Androgen Receptor and triple negative breast cancer: clinical implications and correlation with prognostic and predictive factors

Introducción El Cáncer de Mama Triple Negativo (cmtn) es un grupo heterogéneo, de dispar evolución y sin terapia blanco específica. En la actualidad, se postula al Receptor de Andrógenos (ra) como un prometedor biomarcador en cmtn. Objetivos En el presente estudio analizamos un grupo de pacientes con cmtn con el fin de definir la prevalencia del Receptor de Andrógenos en nuestra población y correlacionarla con factores pronósticos y predictivos. Material y método Se realizó un estudio retrospectivo de determinación de Receptor de Andrógenos por inmunohistoquímica sobre los tacos histológicos de pacientes con diagnóstico de cmtn. Se correlacionó su expresión con las características clinicopatológicas y el impacto en la sobrevida. Resultados Se analizaron 179 pacientes con cmtn, diagnosticadas desde el 1º de enero de 2008 al 31 de diciembre de 2014. El 34,02% de los tacos fueron positivos para ra por ihq. El ra se correlacionó inversamente con Ki 67 y citoqueratinas basales. No se encontró relación con la sobrevida global ni con la sobrevida libre de enfermedad. Conclusiones El rol biológico del Receptor de Andrógenos esta aún en discusión. El cmtn ra positivo se relaciona con menor proliferación celular y menor presencia de marcadores basales. El presente trabajo no demostró impacto en la sobrevida global y en la sobrevida libre de enfermedad. Se deberá seguir estudiando al ra por su gran potencial como blanco terapéutico

Introduction Triple Negative Breast Cancer (tnbc) is a heterogeneous group, with aggressive evolution and without a specific therapeutic target. The Androgen Receptor (ar) is being postulated as a promising biomarker in tnbc. Objectives In this study, we analyze a group of patients with tnbc aiming to define the prevalence of the ar in our population, and the correlation of ar expression with prognostic and predictive factors and its impact on prognosis. Materials and method A retrospective study of determination of ar by immunohistochemistry was done in histological samples of the patients with an invasive Triple Negative Breast Cancer diagnosis. We correlated its expression with clinicopathologic features and clinical outcome. Results 179 patients with tnbc diagnosed from January 2008 to December 2014, where analyzed. An 34.02% of the samples were positive for ar. The ar inversely correlated with Ki 67 and basal cytokeratin. There wasn't found a correlation with overall survival or disease free survival. Conclusions The biological role of the Androgen Receptor is still on discussion. The positive ar tnbc is linked with less cellular proliferation and less presence of basal markers. Although its role as a prognostic factor couldn't be revealed by this job, ar receptor must be investigated to determinated their potential role as treatment target.

Targeting Metabolic Remodeling in Triple Negative Breast Cancer in a Murine Model.

Background: Chemotherapy is the backbone of systemic treatment for triple negative breast cancer (TNBC), which is one of the most relevant breast cancers molecular types due to the ability of tumor cells to develop drug resistance, highlighting the urgent need to design newer and safer drug combinations for treatment. In this context, to overcome tumor cell drug resistance, we employed a novel combinatorial treatment including Doxorubicin, Metformin, and Sodium Oxamate (DoxMetOx). Such pharmacological combination targets indispensable hallmarks of cancer-related to aerobic glycolysis and DNA synthesis. Materials and Methods: Thirty-five female nude mice were transplanted subcutaneously with MDA-MB-231 triple negative human cancer cell line. Once tumors were visible, mice were treated with doxorubicin, metformin, oxamate or all possible pharmacologic combinations. Treatments were administered daily for 15 days and tumors were measured by calipers every day. MicroPET images were taken in three different occasions, basal state, in the middle of the treatment, and at the end of treatment. Western blot analyses, qRT-PCR, flow cytometry, and cytotoxicity assays were performed to elucidate the mechanism of cell death promoted by the drugs in vitro. Results: In this work we assessed the proof of concept of metabolic correction in solid tumors as an effective drug treatment; hence, mice bearing tumors treated with the DoxMetOx therapy showed a complete inhibition of the tumor mass growing in 15 days of treatment depicted by the micro PET images. In vitro studies displayed that the three drugs together act by inhibiting both, mTOR-phosphorylation and expression of LDH-A gene, promoting apoptosis via dependent on the caspase-3 pathway, accompanied by cleavage of PARP. Moreover, induction of autophagy process was observed by the accumulation of LC3-II, a primordial protein implicated in the conformation and elongation of the autophagolysosome. Conclusions: The lack of effective drugs to inhibit TNBC growth is the main cause of therapy failure and tumor relapse. We have showed that targeting crucial molecular pathways in cancer by the combination of Doxorubicin, Metformin, and Oxamate resulted as an efficient and rapid tumor growth inhibitor in a triple negative xenograft model. Our findings are promising for patients diagnosed with TNBC tumors, for which unfortunately there are no reliable drug therapies.

Validation of a network-based strategy for the optimization of combinatorial target selection in breast cancer therapy: siRNA knockdown of network targets in MDA-MB-231 cells as an in vitro model for inhibition of tumor development.

Network-based strategies provided by systems biology are attractive tools for cancer therapy. Modulation of cancer networks by anticancer drugs may alter the response of malignant cells and/or drive network re-organization into the inhibition of cancer progression. Previously, using systems biology approach and cancer signaling networks, we identified top-5 highly expressed and connected proteins (HSP90AB1, CSNK2B, TK1, YWHAB and VIM) in the invasive MDA-MB-231 breast cancer cell line. Here, we have knocked down the expression of these proteins, individually or together using siRNAs. The transfected cell lines were assessed for in vitro cell growth, colony formation, migration and invasion relative to control transfected MDA-MB-231, the non-invasive MCF-7 breast carcinoma cell line and the non-tumoral mammary epithelial cell line MCF-10A. The knockdown of the top-5 upregulated connectivity hubs successfully inhibited the in vitro proliferation, colony formation, anchorage independence, migration and invasion in MDA-MB-231 cells; with minimal effects in the control transfected MDA-MB-231 cells or MCF-7 and MCF-10A cells. The in vitro validation of bioinformatics predictions regarding optimized multi-target selection for therapy suggests that protein expression levels together with protein-protein interaction network analysis may provide an optimized combinatorial target selection for a highly effective anti-metastatic precision therapy in triple-negative breast cancer. This approach increases the ability to identify not only druggable hubs as essential targets for cancer survival, but also interactions most susceptible to synergistic drug action. The data provided in this report constitute a preliminary step toward the personalized clinical application of our strategy to optimize the therapeutic use of anti-cancer drugs.