Triple negative breast cancer: shedding light onto the role of pi3k/akt/mtor pathway

A review of non-classical MAPK family member, MAPK4: A pivotal player in cancer development and therapeutic intervention

Mitogen-Activated Protein Kinases (MAPKs) are serine/threonine protein kinases that play a crucial role in transmitting extracellular signals to the intracellular environment, influencing a wide range of cellular processes including proliferation, differentiation, apoptosis, metabolic activities, immune function and stress response. MAPK4, a non-classical MAPK, is frequently overexpressed in various malignancies, including prostate, breast, cervix, thyroid, and gliomas. It orchestrates cell proliferation, migration, and apoptosis via the AKT/mTOR and/or PDK1 signaling pathways, thus facilitating tumor cell growth. Furthermore, MAPK4 expression is closely associated with the effectiveness of specific inhibitors like PI3K and PARP1, and also correlate with the survival rates of cancer patients. Increasing evidence highlights MAPK4's involvement in the tumor microenvironment, modulating immune response and inflammation-related diseases. This review comprehensively explores the structure, function, and oncogenic role of MAPK4, providing a deeper understanding of its activation and mechanisms of action in tumorigenesis, which might be helpful for the development of innovative therapeutic strategies for cancer management.

Insights into Mechanisms and Promising Triple Negative Breast Cancer Therapeutic Potential for a Water-Soluble Ruthenium Compound

Triple negative breast cancer (TNBC) represents a subtype of breast cancer that does not express the three major prognostic receptors of human epidermal growth factor receptor 2 (HER2), progesterone (PR), and estrogen (ER). This limits treatment options and results in a high rate of mortality. We have reported previously on the efficacy of a water-soluble, cationic organometallic compound (Ru-IM) in a TNBC mouse xenograft model with impressive tumor reduction and targeted tumor drug accumulation. Ru-IM inhibits cancer hallmarks such as migration, angiogenesis, and invasion in TNBC cells by a mechanism that generates apoptotic cell death. Ru-IM displays little interaction with DNA and appears to act by a P53-independent pathway. We report here on the mitochondrial alterations caused by Ru-IM treatment and detail the inhibitory properties of Ru-IM in the PI3K/AKT/mTOR pathway in MDA-MB-231 cells. Lastly, we describe the results of an efficacy study of the TNBC xenografted mouse model with Ru-IM and Olaparib monotherapy and combinatory treatments. We find 59% tumor shrinkage with Ru-IM and 65% with the combination. Histopathological analysis confirmed no test-article-related toxicity. Immunohistochemical analysis indicated an inhibition of the angiogenic marker CD31 and increased levels of apoptotic cleaved caspase 3 marker, along with a slight inhibition of p-mTOR. Taken together, the effects of Ru-IM in vitro show similar trends and translation in vivo. Our investigation underscores the therapeutic potential of Ru-IM in addressing the challenges posed by TNBC as evidenced by its robust efficacy in inhibiting key cancer hallmarks, substantial tumor reduction, and minimal systemic toxicity.

DMC triggers MDA-MB-231 cells apoptosis via inhibiting protective autophagy and PI3K/AKT/mTOR pathway by enhancing ROS level

DMC, a kind of compound derived from the dry flower buds of Cleistocalyx operculatus, has been shown to inhibit the growth of various cancer cells, but research on triple-negative breast cancer cells remains scarce. To explore this issue, MDA-MB-231 cells were selected, and the results showed that DMC has strong proliferation inhibit effects on this kind of cells. The inhibit rate of 30 μM DMC incubated for 24 h was 56.25%, and 40.6% cells were arrested under the G2/M phase. The levels of pro-apoptosis protein Bax and active caspase-3, cleaved PARP and cell cycle related proteins, such as p21 and p27 increased, but apoptosis regulators, like Bcl-2, Cdc 2, Cyclin B1, and LC3 II decreased dramatically. In addition, DMC induced the accumulation of autophagosomes and autophagic substrates, and the combination of DMC with CQ promoted apoptosis of MDA-MB-231 cells, which suggested that DMC induced apoptosis partly by blocking autophagy flow. Moreover, the phosphorylation levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and its mechanistic target of rapamycin kinase (mTOR) were also decreased after 30 μM DMC incubating for 24 h. The proteins play a critical role in cell proliferation, apoptosis, and autophagy modulation. The inhibition of autophagy flow and PI3K/AKT/mTOR pathway could be reversed after being treated with ROS scavenger NAC. Altogether, the results of the present study suggest that DMC effectively induces apoptosis and growth inhibition in MDA-MB-231 cells through blocking autophagy flow and regulating the PI3K/AKT/mTOR pathway by increasing ROS level.

Osteopontin promotes tumor growth and metastasis and GPX4-mediated anti-lipid peroxidation in triple-negative breast cancer by activating the PI3k/Akt/mTOR pathway

PURPOSE

Triple-negative breast cancer (TNBC) features high aggressiveness, metastasis rate, drug resistance as well as poor prognosis. Osteopontin (OPN) is a key protein in the process of osteogenesis and has emerged as a new tumor marker in recent years.

METHODS

Cell viability was tested with the CCK-8 kit. Transwell and wound healing were adopted to test cell invasive and migratory abilities. Tumor sphere formation was detected by tumor sphere formation assay. Human umbilical vein endothelial cell (HUVEC) tube formation assay was used to measure the angiogenesis of tumor cells. Western blot was applied for the estimation of the expression of cancer stem cell markers, angiogenesis-, signaling pathway-related proteins as well as OPN. Bioinformatics tools predicted OPN expression in breast cancer tissues. The levels of oxidative stress-related markers were assessed with ELISA. Following the overexpression of OPN in MD-MB-436 cells and the addition of the PI3K/AKT/mTOR pathway inhibitor LY294002, the aforementioned functional experiments were implemented again to investigate the mechanism. Finally, in vivo experiments of tumor-bearing mice were performed for further verification.

RESULTS

The proliferative, invasive, migratory and tumor sphere formation capabilities as well as angiogenesis of TNBC cells were conspicuously increased in contrast to non-TNBC cell lines. OPN expression in TNBC tissues and cells was dramatically enhanced. OPN upregulation significantly elevated cell proliferative, invasive and migratory capabilities as well as tumor sphere formation and angiogenesis. The mechanism might be achieved by activating PI3K/AKT/mTOR signaling to regulate glutathione peroxidase 4 (GPX4)-mediated anti-lipid peroxidation.

CONCLUSION

OPN promoted tumor sphere formation and angiogenesis in TNBC by activating the PI3K/AKT/mTOR pathway to regulate GPX4-mediated anti-lipid peroxidation levels.

Investigation the apoptotic effect of silver nanoparticles (Ag-NPs) on MDA-MB 231 breast cancer epithelial cells via signaling pathways

Background

The discovery of novel cancer therapeutic strategies leads to the development of nanotechnology-based methods for cancer treatment. Silver nanoparticles (Ag-NPs) have garnered considerable interest owing to their size, shape, and capacity to modify chemical, optical, and photonic properties. This study aimed to investigate the impact of Ag-NPs on inducing of apoptosis in MDA-MB 231 cells by examining specific signaling pathways.

Materials and methods

The cytotoxicity of Ag-NPs was determined using an MTT assay in MDA-MB 231 cells. The apoptotic effects were assessed using the Annexin-V/PI assay. Real-time PCR and western blotting were conducted to analyze the expression of apoptosis-related genes and proteins, respectively. Levels of ERK1/2 and cyclin D1 were measured using ELISA. Cell cycle assay was determined by flow cytometry. Cell migration was evaluated by scratch assay.

Results

The results revealed that Ag-NPs triggered apoptosis and cell cycle arrest in MDA-MB 231 cells. The expression level of Bax (pro-apoptotic gene) was increased, while Bcl-2 (anti-apoptotic gene) expression was decreased. Increased apoptosis was correlated with increased levels of p53 and PTEN. Additionally, notable alterations were observed in protein expression related to the Janus kinase/Signal transducers (JAK/STAT) pathway, including p-AKT. Additionally, reduced expression of h-TERT was observed following exposure to Ag-NPs. ELISA results demonstrated a significant reduction in p-ERK/Total ERK and cyclin D1 levels in Ag-NPs-exposed MDA-MB 231 cells. Western blotting analysis also confirmed the reduction of p-ERK/Total ERK and cyclin D1. Decreased level of cyclin D is associated with suppression of cell cycle progression. The migratory ability of MDA-MB-231 cells was reduced upon treatment with Ag-NPs.

Conclusions

Our findings revealed that Ag-NPs influenced the proliferation, apoptosis, cell cycle, and migration in MDA-MB 231 cells, possibly by modulating protein expression of the AKT/ERK/Cyclin D1 axis.

Identification of a targetable JAK-STAT enriched androgen receptor and androgen receptor splice variant positive triple-negative breast cancer subtype

Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (∼80%) but also expresses AR splice variants (AR-SVs) (∼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.

Emerging targeted therapeutic strategies for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC), a subtype of breast cancer that lacks expression of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), has clinical features including a high degree of invasiveness, an elevated risk of metastasis, tendency to relapse, and poor prognosis. It constitutes around 10-15% of all breast cancer, and having heredity of BRCA1 mutated breast cancer could be a reason for the occurrence of TNBC in women. Overexpression of cellular and molecular targets, i.e. CD44 receptor, EGFR receptor, Folate receptor, Transferrin receptor, VEGF receptor, and Androgen receptor, have emerged as promising targets for treating TNBC. Signalling pathways such as Notch signalling and PI3K/AKT/mTOR also play a significant role in carrying out and managing crucial pro-survival and pro-growth cellular processes that can be utilised for targeted therapy against triple-negative breast cancer. This review sheds light on various targeting strategies, including cellular and molecular targets, signalling pathways, poly (ADP-ribose) polymerase inhibitors, antibody-drug conjugates, and immune checkpoint inhibitors PARP, immunotherapy, ADCs have all found a place in the current TNBC therapeutic paradigm. The role of photothermal therapy (PTT) and photodynamic therapy (PDT) has also been explored briefly.

Targeting Breast Cancer: The Familiar, the Emerging, and the Uncharted Territories

Breast cancer became the most diagnosed cancer in the world in 2020. Chemotherapy is still the leading clinical strategy in breast cancer treatment, followed by hormone therapy (mostly used in hormone receptor-positive types). However, with our ever-expanding knowledge of signaling pathways in cancer biology, new molecular targets are identified for potential novel molecularly targeted drugs in breast cancer treatment. While this has resulted in the approval of a few molecularly targeted drugs by the FDA (including drugs targeting immune checkpoints), a wide array of signaling pathways seem to be still underexplored. Also, while combinatorial treatments have become common practice in clinics, the majority of these approaches seem to combine molecularly targeted drugs with chemotherapeutic agents. In this manuscript, we start by analyzing the list of FDA-approved molecularly targeted drugs for breast cancer to evaluate where molecular targeting stands in breast cancer treatment today. We will then provide an overview of other options currently under clinical trial or being investigated in pre-clinical studies.

A scientometric analysis of research trends on targeting mTOR in breast cancer from 2012 to 2022

Over the past decade, thousands of articles have been published on the mechanistic target of rapamycin (mTOR) and its role in breast cancer. However, the variability and heterogeneity of academic data may impact the acquisition of published research information. Due to the large number, heterogeneity, and varying quality of publications related to mTOR and breast cancer, sorting out the present state of the research in this area is critical for both researchers and clinicians. Therefore, scientometric techniques and visualization tools were employed to analyze the large number of bibliographic metadata related to the research area of mTOR and breast cancer. The features of relevant publications were searched from 2012 to 2022 to evaluate the present status of research and the evolution of research hotspots in this particular field. Web of Science was utilized to extract all relevant publications from 2012 to 2022. Subsequently, Biblioshiny and VOSviewer were utilized to obtain data on the most productive countries, authors, and institutions, annual publications and citations, the most influential journals and articles, and the most frequently occurring keywords. In total, 1,471 publications were retrieved, comprising 1,167 original articles and 304 reviews. There was a significant rise in publications between 2015 and 2018, followed by a sharp decline in 2019 and a rebound since then. The publication with the highest number of citations was a 2012 review authored by Baselga et al. The United States had the highest number of publications, citations and connections among all countries. Oncotarget had the highest number of published articles among all the journals, and José Baselga had the strongest links with other authors. Excluding the search topics, the most frequently used words were "expression" (n = 297), "growth" (n = 228), "activation" (n = 223), "pathway" (n = 205), and "apoptosis" (n = 195). mTOR is crucially involved in breast cancer pathogenesis, but its exact mechanism of action remains controversial and warrants further investigation. The scientometric analysis provides a distinct overview of the existing state of research and highlights the topical issues that deserve further exploration.

Update on Classic and Novel Approaches in Metastatic Triple-Negative Breast Cancer Treatment: A Comprehensive Review

Triple-negative breast cancer (TNBC) accounts for almost 15% of all diagnosed breast cancers and often presents high rates of relapses and metastases, with generally poor prognosis despite multiple lines of treatment. Immunotherapy has radically changed the approach of clinicians towards TNBC in the last two to three years, even if targeted and specific therapeutic options are still missing; this unmet need is further justified by the extreme molecular and clinical heterogeneity of this subtype of breast cancer and by the weak response to both single-agent and combined therapies. In March 2023, the National Comprehensive Cancer Network (NCCN), the main association of cancer centers in the United States, released the last clinical practice guidelines, with an update on classic and novel approaches in the field of breast cancer. The purpose of this comprehensive review is to summarize the latest findings in the setting of metastatic TNBC treatment, focusing on each category of drugs approved by the Food and Drug Administration (FDA) and included in the NCCN guidelines. We also introduce part of the latest published studies, which have reported new and promising molecules able to specifically target some of the biomarkers involved in TNBC pathogenesis. We searched the PubMed and Scopus databases for free full texts reported in the literature of the last 5 years, using the words "triple-negative breast cancer" or "TNBC" or "basal-like". The articles were analyzed by the authors independently and double-blindly, and a total of 114 articles were included in the review.

Obesity Is Associated with Immunometabolic Changes in Adipose Tissue That May Drive Treatment Resistance in Breast Cancer: Immune-Metabolic Reprogramming and Novel Therapeutic Strategies

White adipose tissue (WAT) represents an endocrinologically and immunologically active tissue whose primary role is energy storage and homeostasis. Breast WAT is involved in the secretion of hormones and proinflammatory molecules that are associated with breast cancer development and progression. The role of adiposity and systemic inflammation in immune responses and resistance to anti-cancer treatment in breast cancer (BC) patients is still not clear. Metformin has demonstrated antitumorigenic properties both in pre-clinical and clinical studies. Nevertheless, its immunomodulating properties in BC are largely unknown. This review aims to evaluate the emerging evidence on the crosstalk between adiposity and the immune-tumour microenvironment in BC, its progression and treatment resistance, and the immunometabolic role of metformin in BC. Adiposity, and by extension subclinical inflammation, are associated with metabolic dysfunction and changes in the immune-tumour microenvironment in BC. In oestrogen receptor positive (ER+) breast tumours, it is proposed that these changes are mediated via a paracrine interaction between macrophages and preadipocytes, leading to elevated aromatase expression and secretion of pro-inflammatory cytokines and adipokines in the breast tissue in patients who are obese or overweight. In HER2+ breast tumours, WAT inflammation has been shown to be associated with resistance to trastuzumab mediated via MAPK or PI3K pathways. Furthermore, adipose tissue in patients with obesity is associated with upregulation of immune checkpoints on T-cells that is partially mediated via immunomodulatory effects of leptin and has been paradoxically associated with improved responses to immunotherapy in several cancers. Metformin may play a role in the metabolic reprogramming of tumour-infiltrating immune cells that are dysregulated by systemic inflammation. In conclusion, evidence suggests that body composition and metabolic status are associated with patient outcomes. To optimise patient stratification and personalisation of treatment, prospective studies are required to evaluate the role of body composition and metabolic parameters in metabolic immune reprogramming with and without immunotherapy in patients with BC.

Anthocyanins Reduce Cell Invasion and Migration through Akt/mTOR Downregulation and Apoptosis Activation in Triple-Negative Breast Cancer Cells: A Systematic Review and Meta-Analysis

BACKGROUND

Studies have suggested the chemopreventive effects of anthocyanins on breast cancer carcinogenesis. This systematic review and meta-analysis aimed to evaluate the effect of anthocyanins on triple-negative breast cancer cells (TNBC) cultured in vitro.

METHODS

We searched for all relevant studies that evaluated the mechanisms of migration, invasion, Akt/mTOR and MAPK pathways, and apoptosis, using PubMed and Scopus. Means and standard deviation were used, and a randomized effects model was applied, with a confidence interval of 95%. Statistical heterogeneity between studies was assessed using the Chi2 test and I2 statistics. All analyses were performed using RevMan software (version 5.4).

RESULTS

Eleven studies were included in the systematic review and ten in the meta-analysis, where the roles of anthocyanin-enriched extract or cyanidin-3-O-glucoside (C-3-O-G) on MDA-MB-231 and MDA-MB-453 cells were investigated.

DISCUSSION

There was a significant reduction in invasion (mean difference: -98.64; 95% CI: -153.98, -43.3; p ˂ 0.00001) and migration (mean difference: -90.13; 95% CI: -130.57, -49.68; p ˂ 0.00001) in TNBC cells after anthocyanins treatment. Anthocyanins also downregulated Akt (mean difference: -0.63; 95% CI: -0.70, -0.57; p ˂ 0.00001) and mTOR (mean difference: -0.93; 95% CI: -1.58, -0.29; p = 0.005), while JNK (mean difference: -0.06; 95% CI: -1.21, 1.09; p = 0.92) and p38 (mean difference: 0.05; 95% CI: -1.32, 1.41; p = 0.95) were not modulated. There was also an increase in cleaved caspase-3 (mean difference: 1.13; 95% CI: 0.11, 2.16; p = 0.03), cleaved caspase-8 (mean difference: 1.64; 95% CI: 0.05, 3.22; p = 0.04), and cleaved PARP (mean difference: 0.93; 95% CI: 0.54, 1.32). Although the difference between control and anthocyanin groups was not significant regarding apoptosis rate (mean difference: 3.63; 95% CI: -2.88, 10.14; p = 0.27), the analysis between subgroups showed that anthocyanins are more favorable in inducing overall apoptosis (p ˂ 0.00001).

CONCLUSION

The results show that anthocyanins hold promise in fighting against TNBC, but their effects should not be generalized. In addition, further primary studies should be conducted so that more accurate conclusions can be drawn.

Recent Advances in Targeted Nanocarriers for the Management of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a life-threatening form of breast cancer which has been found to account for 15% of all the subtypes of breast cancer. Currently available treatments are significantly less effective in TNBC management because of several factors such as poor bioavailability, low specificity, multidrug resistance, poor cellular uptake, and unwanted side effects being the major ones. As a rapidly growing field, nano-therapeutics offers promising alternatives for breast cancer treatment. This platform provides a suitable pathway for crossing biological barriers and allowing sustained systemic circulation time and an improved pharmacokinetic profile of the drug. Apart from this, it also provides an optimized target-specific drug delivery system and improves drug accumulation in tumor cells. This review provides insights into the molecular mechanisms associated with the pathogenesis of TNBC, along with summarizing the conventional therapy and recent advances of different nano-carriers for the management of TNBC.

The diagnostic accuracy of PIK3CA mutations by circulating tumor DNA in breast cancer: an individual patient data meta-analysis

Background:

The circulating tumor DNA (ctDNA) diagnostic accuracy for detecting phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations in breast cancer (BC) is under discussion. We aimed to compare plasma and tissue PIK3CA alterations, encompassing factors that could affect the results.

Methods:

Two reviewers selected studies from different databases until December 2020. We considered BC patients with matched tumor tissue and plasma ctDNA. We performed meta-regression and subgroup analyses to explore sources of heterogeneity concerning tumor burden, diagnostic technique, sample size, sampling time, biological subtype, and hotspot mutation. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the related area under the curve (AUC) were elaborated for the overall population and each subgroup.

Results:

The pooled analysis was carried out on 25 cohorts for a total of 1966 patients. The overall ctDNA sensitivity and specificity were 0.73 (95% CI: 0.70–0.77) and 0.87 (95% CI: 0.85–0.89). The AUC was 0.93. Pooled concordance, negative predictive value and positive predictive value values were 0.87 (95% CI: 0.82–0.92), 0.86 (95% CI: 0.81–0.90), and 0.89 (95% CI: 0.81–0.95) with pooled PLR, NLR, and DOR of 7.94 (95% CI: 4.90–12.86), 0.33 (95% CI: 0.25–0.45), and 33.41 (95% CI: 17.23–64.79), respectively. The pooled results consistently favored next-generation sequencing (NGS)- over polymerase chain reaction-based methodologies. The best ctDNA performance in terms of sensitivity, specificity, and AUC (0.85, 0.99, and 0.94, respectively) was observed in the low-time sampling subgroup (⩽18 days between tissue and plasma collection). Meta-regression and subgroup analyses highlighted sampling time as a possible major cause of heterogeneity.

Conclusions:

These findings reliably estimate the high ctDNA accuracy for the detection of PIK3CA mutations. A ctDNA-first approach for the assessment of PIK3CA mutational status by NGS may accurately replace tissue tumor sampling, representing the preferable strategy at diagnosis of metastatic BC in patients who present with visceral involvement and at least two metastatic lesions, primarily given low clinical compliance or inaccessible metastatic sites.

Nanotechnological Approaches for the Treatment of Triple-Negative Breast Cancer: A Comprehensive Review

Breast cancer is the most prevalent cancer in women around the world, having a sudden spread nowadays because of the poor sedentary lifestyle of people. Comprising several subtypes, one of the most dangerous and aggressive ones is triple-negative breast cancer or TNBC. Even though conventional surgical approaches like single and double mastectomy and preventive chemotherapeutic approaches are available, they are not selective to cancer cells and are only for symptomatic treatment. A new branch called nanotechnology has emerged in the last few decades that offers various novel characteristics, such as size in nanometric scale, enhanced adherence to multiple targeting moieties, active and passive targeting, controlled release, and site-specific targeting. Among various nanotherapeutic approaches like dendrimers, lipid-structured nanocarriers, carbon nanotubes, etc., nanoparticle targeted therapeutics can be termed the best among all for their specific cytotoxicity to cancer cells and increased bioavailability to a target site. This review focuses on the types and molecular pathways involving TNBC, existing treatment strategies, various nanotechnological approaches like exosomes, carbon nanotubes, dendrimers, lipid, and carbon-based nanocarriers, and especially various nanoparticles (NPs) like polymeric, photodynamic, peptide conjugated, antibody-conjugated, metallic, inorganic, natural product capped, and CRISPR based nanoparticles already approved for treatment or are under clinical and pre-clinical trials for TNBC.

Associations of Computed Tomography Image-Assessed Adiposity and Skeletal Muscles with Triple-Negative Breast Cancer

Obesity measured by anthropometrics is associated with increased risk of triple-negative breast cancer (TNBC). It is unclear to what extent specific adipose tissue components, aside from muscle, are associated with TNBC. This retrospective study included 350 breast cancer patients who received treatment between October 2011 and April 2020 with archived abdominal or pelvic computed tomography (CT) images. We measured the areas of adipose tissue and five-density levels of skeletal muscle on patients' third lumbar vertebra (L3) image. Logistic regression was performed to examine the associations of specific adiposity and skeletal muscles components and a four-category body composition phenotype with the TNBC subtype. Results showed that higher vs. lower areas (3rd vs. 1st tertiles) of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were associated with increased odds of TNBC vs. non-TNBC after adjusting for age, race, stage, tumor grade, tumor size, and skeletal muscle areas (adjusted odds ratio [AOR], 11.25 [95% CI = 3.46-36.52]) and (AOR, 10.34 [95% CI = 2.90-36.90]) respectively. Higher areas of low density muscle was also associated with increased odds of TNBC (AOR, 3.15 [95% CI = 1.05-10.98]). Compared to normal body composition (low adipose tissue/high muscle), high adiposity/high muscle was associated with higher odds of TNBC (AOR, 5.54 [95% CI = 2.12-14.7]). These associations were mainly in premenopausal women and among patients with the CT performed after breast cancer surgery. Specific adipose tissue and low-density muscle can be associated with the TNBC subtype in breast cancer patients. The direction of association warrants confirmation by prospective studies.

Exploring the Pharmacological Mechanisms of Xihuang Pills Against Prostate Cancer via Integrating Network Pharmacology and Experimental Validation In Vitro and In Vivo

Background: Drug resistance is the major cause of increasing mortality in prostate cancer (PCa). Therefore, it an urgent to develop more effective therapeutic agents for PCa treatment. Xihuang pills (XHP) have been recorded as the efficient anti-tumor formula in ancient Chinese medical literature, which has been utilized in several types of cancers nowadays. However, the effect protective role of XHP on the PCa and its underlying mechanisms are still unclear.

Methods: The active ingredients of XHP were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and BATMAN-TCM. The potential targets of PCa were acquired from the Gene Cards and OMIM databases. R language and Perl language program were utilized to clarify the interaction between the PCa-related targets and the potential targets of XHP. The potential targets of XHP for prostate cancer were gathered from the Gene ontology and KEGG pathway. Furthermore, cell proliferation assays were verified by PC3 and LNCaP cells. The efficacy and potential mechanism tests were confirmed by the PCa PC3 cells and mice subcutaneous transplantation. The effects of PI3K/Akt/mTOR-related proteins on proliferation, apoptosis, and cell cycle of PCa cells were measured by the Cell Counting Kit-8(CCK8), TUNEL assay, real-time quantitative reverse transcription PCR (QRT-PCR), and Western Blotting, respectively.

Results: The active components of four traditional Chinese medicines in XHP were searched on the TCMSP and Batman TCM database. The biological active components of XHP were obtained as OB ≥30% and DL ≥0.18. The analysis of gene ontology and KEGG pathway identified the PI3K/Akt/mTOR signaling pathway as the XHP-associated pathway. Collectively, the results of in vitro and in vivo experiments showed that XHP had the effect of inhibiting on the proliferation of PC3 and LNCaP cells. XHP promoted the apoptosis and restrained the cell cycle and invasion of the PC3 cells and subcutaneous transplantation. Meanwhile, the suppression of XHP on the level of expression of PI3K, Akt, and mTOR-pathway-related pathway proteins has been identified in a dose-dependent manner.

Conclusion: PI3K/Akt/mTOR pathway-related pathway proteins were confirmed as the potential XHP-associated targets for PCa. XHP can suppress the proliferation of prostate cancer via inhibitions of the PI3K/Akt/mTOR pathway.

The Discovery of New Drug-Target Interactions for Breast Cancer Treatment

Drug–target interaction (DTIs) prediction plays a vital role in probing new targets for breast cancer research. Considering the multifaceted challenges associated with experimental methods identifying DTIs, the in silico prediction of such interactions merits exploration. In this study, we develop a feature-based method to infer unknown DTIs, called PsePDC-DTIs, which fuses information regarding protein sequences extracted by pseudo-position specific scoring matrix (PsePSSM), detrended cross-correlation analysis coefficient (DCCA coefficient), and an FP2 format molecular fingerprint descriptor of drug compounds. In addition, the synthetic minority oversampling technique (SMOTE) is employed for dealing with the imbalanced data after Lasso dimensionality reduction. Then, the processed feature vectors are put into a random forest classifier to perform DTIs predictions on four gold standard datasets, including nuclear receptors (NR), G-protein-coupled receptors (GPCR), ion channels (IC), and enzymes (E). Furthermore, we explore new targets for breast cancer treatment using its risk genes identified from large-scale genome-wide genetic studies using PsePDC-DTIs. Through five-fold cross-validation, the average values of accuracy in NR, GPCR, IC, and E datasets are 95.28%, 96.19%, 96.74%, and 98.22%, respectively. The PsePDC-DTIs model provides us with 10 potential DTIs for breast cancer treatment, among which erlotinib (DB00530) and FGFR2 (hsa2263), caffeine (DB00201) and KCNN4 (hsa3783), as well as afatinib (DB08916) and FGFR2 (hsa2263) are found with direct or inferred evidence. The PsePDC-DTIs model has achieved good prediction results, establishing the validity and superiority of the proposed method.

Doxorubicin-Resistant TNBC Cells Exhibit Rapid Growth with Cancer Stem Cell-like Properties and EMT Phenotype, Which Can Be Transferred to Parental Cells through Autocrine Signaling

Emerging evidence suggests that breast cancer stem cells (BCSCs), and epithelial–mesenchymal transition (EMT) may be involved in resistance to doxorubicin. However, it is unlear whether the doxorubicin-induced EMT and expansion of BCSCs is related to cancer dormancy, or outgrowing cancer cells with maintaining resistance to doxorubicin, or whether the phenotypes can be transferred to other doxorubicin-sensitive cells. Here, we characterized the phenotype of doxorubicin-resistant TNBC cells while monitoring the EMT process and expansion of CSCs during the establishment of doxorubicin-resistant MDA-MB-231 human breast cancer cells (DRM cells). In addition, we assessed the potential signaling associated with the EMT process and expansion of CSCs in doxorubicin-resistance of DRM cells. DRM cells exhibited morphological changes from spindle-shaped MDA-MB-231 cells into round-shaped giant cells. They exhibited highly proliferative, EMT, adhesive, and invasive phenotypes. Molecularly, they showed up-regulation of Cyclin D1, mesenchymal markers (β-catenin, and N-cadherin), MMP-2, MMP-9, ICAM-1 and down-regulation of E-cadherin. As the molecular mechanisms responsible for the resistance to doxorubicin, up-regulation of EGFR and its downstream signaling, were suggested. AKT and ERK1/2 expression were also increased in DRM cells with the advancement of resistance to doxorubicin. Furthermore, doxorubicin resistance of DRM cells can be transferred by autocrine signaling. In conclusion, DRM cells harbored EMT features with CSC properties possessing increased proliferation, invasion, migration, and adhesion ability. The doxorubicin resistance, and doxorubicin-induced EMT and CSC properties of DRM cells, can be transferred to parental cells through autocrine signaling. Lastly, this feature of DRM cells might be associated with the up-regulation of EGFR.

Ginsenoside (20S)-protopanaxatriol induces non-protective autophagy and apoptosis by inhibiting Akt/mTOR signaling pathway in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) lacks a recognized therapeutic molecular target and has an unfavorable prognosis. (20S)-Protopanaxatriol (g-PPT, PPT) is an active metabolite extracted from ginseng. Accumulating evidence suggests that it has good anti-cancer activity in vivo and in vitro. In this study, we aimed to elucidate the anti-tumor effects of PPT in TNBC cells and tumor-bearing mice, as well as the relevant molecular mechanisms of autophagy and apoptosis. In vitro, we have found that PPT is capable of inducing non-protective autophagy and apoptosis, thus exerting some anti-proliferative and anti-migration activity in TNBC cells. And in vivo, the therapeutic effects of PPT were evaluated by xenograft mouse models. The potential binding mode of PPT and Akt was predicted by molecular docking. Our findings indicated that PPT treatment induced non-protective autophagy in TNBC cells by inhibiting the Akt/mTOR signaling pathway. Therefore, PPT may be a potential treatment for TNBC in the future.

Clinically Translatable Approaches of Inhibiting TGF-β to Target Cancer Stem Cells in TNBC

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that disproportionally accounts for the majority of breast cancer-related deaths due to the lack of specific targets for effective treatments. In this review, we highlight the complexity of the transforming growth factor-beta family (TGF-β) pathway and discuss how the dysregulation of the TGF-β pathway promotes oncogenic attributes in TNBC, which negatively affects patient prognosis. Moreover, we discuss recent findings highlighting TGF-β inhibition as a potent method to target mesenchymal (CD44⁺/CD24^-) and epithelial (ALDH^high) cancer stem cell (CSC) populations. CSCs are associated with tumorigenesis, metastasis, relapse, resistance, and diminished patient prognosis; however, due to differential signal pathway enrichment and plasticity, these populations remain difficult to target and persist as a major barrier barring successful therapy. This review highlights the importance of TGF-β as a driver of chemoresistance, radioresistance and reduced patient prognosis in breast cancer and highlights novel treatment strategies which modulate TGF-β, impede cancer progression and reduce the rate of resistance generation via targeting the CSC populations in TNBC and thus reducing tumorigenicity. Potential TGF-β inhibitors targeting based on clinical trials are summarized for further investigation, which may lead to the development of novel therapies to improve TNBC patient prognosis.

Moving Towards Targeted Therapies for Triple-Negative Breast Cancer

PURPOSE OF REVIEW

In this review, we discuss targets of interest in Triple-negative breast cancer (TNBC), approved targeted agents and the results of the clinical trials that led to their approval. Additionally, we review ongoing clinical trials evaluating the use of novel targeted agents in the treatment of TNBC.

RECENT FINDINGS

TNBC accounts for 15-20% of all breast cancer cases and is associated with worse clinical outcomes. Patients have a higher risk of metastatic recurrence and inferior overall survival compared to other breast cancer subtypes. Cytotoxic chemotherapy has historically been the mainstay of treatment for TNBC. In recent years, we have seen a surge in clinical trials investigating the use of targeted agents in TNBC and now have approval for targeted therapies in select patients. Inhibitors of PARP (olaparib and talazoparib), PD-L1 (atezolizumab) and an antibody drug conjugate targeting Trop-2 (sacituzumab govitecan-hziy) are now approved for the use in select groups of patients with TNBC.

SUMMARY

Various novel targeted agents as monotherapy, dual targeted combinations, and chemotherapy combinations are currently under investigation. The results are promising and may significantly improve patient outcomes in TNBC.

Targeted Drug Therapy to Overcome Chemoresistance in Triple-negative Breast Cancer

Triple-negative Breast Cancer (TNBC) is the most aggressive and prevailing breast cancer subtype. The chemotherapeutics used in the treatment of TNBC suffer from chemoresistance, dose-limiting toxicities and off-target side effects. As a result, conventional chemotherapeutics are unable to prevent tumor growth, metastasis and result in failure of therapy. Various new targets such as BCSCs surface markers (CD44, CD133, ALDH1), signaling pathways (IL-6/JAK/STAT3, notch), pro and anti-apoptotic proteins (Bcl-2, Bcl-xL, DR4, DR5), hypoxic factors (HIF-1α, HIF-2α) and drug efflux transporters (ABCC1, ABCG2 and ABCB1) have been exploited to treat TNBC. Further, to improve the efficacy and safety of conventional chemotherapeutics, researchers have tried to deliver anticancer agents specifically to the TNBCs using nanocarrier based drug delivery. In this review, an effort has been made to highlight the various factors responsible for the chemoresistance in TNBC, novel molecular targets of TNBC and nano-delivery systems employed to achieve sitespecific drug delivery to improve efficacy and reduce off-target side effects.

Curcumin: Modulator of Key Molecular Signaling Pathways in Hormone-Independent Breast Cancer

Simple Summary

Breast cancer remains the most commonly diagnosed cancer and the leading cause of cancer death among females worldwide. It is a highly heterogeneous disease, classified according to hormone and growth factor receptor expression. Patients with triple negative breast cancer (TNBC) (estrogen receptor-negative/progesterone receptor-negative/human epidermal growth factor receptor (HER2)-negative) and hormone-independent HER2 overexpressing subtypes still represent highly aggressive behavior, metastasis, poor prognosis, and drug resistance. Thus, new alternative anticancer agents based on the use of natural products have been receiving enormous attention. In this regard, curcumin is a promising lead in cancer drug discovery due its ability to modulate a diverse range of molecular targets and signaling pathways. The current review has emphasized the underlying mechanism of curcumin anticancer action mediated through the modulation of PI3K/Akt/mTOR, JAK/STAT, MAPK, NF-ĸB, p53, Wnt/β-catenin, apoptosis, and cell cycle pathways in hormone-independent breast cancer, providing frameworks for future studies and insights to improve its efficiency in clinical practice.

Abstract

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide. Despite the overall successes in breast cancer therapy, hormone-independent HER2 negative breast cancer, also known as triple negative breast cancer (TNBC), lacking estrogens and progesterone receptors and with an excessive expression of human epidermal growth factor receptor 2 (HER2), along with the hormone-independent HER2 positive subtype, still remain major challenges in breast cancer treatment. Due to their poor prognoses, aggressive phenotype, and highly metastasis features, new alternative therapies have become an urgent clinical need. One of the most noteworthy phytochemicals, curcumin, has attracted enormous attention as a promising drug candidate in breast cancer prevention and treatment due to its multi-targeting effect. Curcumin interrupts major stages of tumorigenesis including cell proliferation, survival, angiogenesis, and metastasis in hormone-independent breast cancer through the modulation of multiple signaling pathways. The current review has highlighted the anticancer activity of curcumin in hormone-independent breast cancer via focusing on its impact on key signaling pathways including the PI3K/Akt/mTOR pathway, JAK/STAT pathway, MAPK pathway, NF-ĸB pathway, p53 pathway, and Wnt/β-catenin, as well as apoptotic and cell cycle pathways. Besides, its therapeutic implications in clinical trials are here presented.

The feasibility of circulating tumor DNA analysis as a marker of recurrence in triple-negative breast cancer

Triple-negative breast cancer (TNBC) has a poorer prognosis than other breast cancer subtypes; therefore, identifying markers of early recurrence is important. The present study aimed to establish a liquid biopsy protocol for droplet digital PCR-based detection of frequently mutated genes in patients with TNBC. Tumor DNA from 36 patients with TNBC who relapsed within 2 years after surgical resection was retrospectively analyzed. Somatic mutational profiles were evaluated using targeted sequencing to identify frequently mutated genes and genes associated with molecularly targeted therapies. The association between genetic alterations and associated protein phosphorylation was investigated using immunohistochemical analysis. Recurrent hot spot mutations in the plasma were monitored over time. Mutation-specific probes were used to successfully detect mutations in the blood samples of patients who were positive for PIK3CA H1047R and AKT1 E17K mutations. Somatic mutations in AKT1 (14.9%) and PIK3CA (25.5%) were frequently identified in the data. Robust phosphorylation of AKT and S6RP was more common in tumors with PIK3CA H1047R and AKT1 E17K mutational background than in tumors with wild-type PIK3CA and AKT1. In conclusion, the present study evaluated a high-sensitivity detection system for frequently mutated genes that was also applicable for cell-free DNA. The PI3K/AKT pathway was revealed to be activated in patients harboring PIK3CA H1047R and AKT1 E17K mutations; therefore, the PI3K/AKT pathway may be a promising candidate for targeted therapy in these patients.

Innovations in targeted therapies for triple negative breast cancer

PURPOSE OF REVIEW

Triple negative breast cancer (TNBC) is defined by a lack of targets, namely hormone receptor (HR) expression and human epidermal growth factor receptor 2 amplification. Cytotoxic chemotherapy remains the mainstay of treatment. Though TNBC constitutes approximately 10-15% of breast cancer, it is disproportionally lethal, but it is hoped that outcomes will improve as targetable oncogenic drivers are identified.

RECENT FINDINGS

Translational work in TNBC has focused on subsets defined by defects in homologous recombination repair, immune cell infiltration, or programmed death ligand receptor 1 expression, an over-active phosphoinositide-3 kinase pathway, or expression of androgen receptors. Though not specific to TNBC, the novel cell surface antigen trophoblast antigen 2 has also been identified and successfully targeted. This work has led to Food and Drug Administration approvals for small molecule poly-ADP-ribosyl polymerase inhibitors in patients with deleterious germline mutations in BRCA1 or BRCA2, the combination of nab-paclitaxel with immune checkpoint inhibitor antibodies in the first-line metastatic setting for programmed death ligand receptor 1+ TNBC, and use of the antibody-drug conjugate sacituzumab govitecan in the later-line metastatic setting.

SUMMARY

Identification of targetable oncogenic drivers in TNBC is an area of intense cancer biology research, hopefully translating to new therapies and improved outcomes.

Hsa_circ_0000199 facilitates chemo-tolerance of triple-negative breast cancer by interfering with miR-206/613-led PI3K/Akt/mTOR signaling

Increasing attentions have been paid to the role of circRNAs in the etiology of triple-negative breast cancer (TNBC), and we strived to figure out the association of circRNA AKT3/miRNA axis with TNBC chemo-resistance. Altogether 207 BC patients were divided into TNBC group (n=83) and non-TNBC group (n=124), and MCF-10A, MDA-MB-231, MDA-MB-468, SK-BR-3 and MCF-7 cell lines were prepared in advance. Expressions of AKT3-derived circRNAs and relevant miRNAs in the TNBC tissues and cell lines were determined by employing real-time polymerase chain reaction (PCR). It was indicated that hsa_circ_0000199 expression was higher in TNBC tissues than in non-TNBC tissues, and high hsa_circ_0000199 expression was predictive of large tumor size, advanced TNM grade, high Ki-67 level and poor 3-year survival of TNBC patients (all P<0.05). Furthermore, miR-613 and miR-206 were sponged and negatively regulated by hsa_circ_0000199 (P<0.001), and PI3K/Akt/mTOR signaling was depressed by si-hsa_circ_0000199 in TNBC cell lines (P<0.01). Ultimately, miR-206/miR-613 inhibitor reversed impacts of si-hsa_circ_0000199 on PI3K/Akt/mTOR signaling, proliferation, migration, invasion, chemo-sensitivity and autophagy of TNBC cells (all P<0.01). Conclusively, silencing of hsa_circ_0000199 enhanced TNBC chemo-sensitivity by promoting miR-206/miR-613 expression and deactivating PI3K/Akt/mTOR signaling, which was conducive to improving chemotherapeutic efficacy of TNBC patients.

Obesity and Energy Balance Considerations in Triple-Negative Breast Cancer

ABSTRACT

Obesity is an increasingly prevalent state of energy imbalance that contributes to breast cancer risk and outcomes. The effects of obesity differ by breast cancer subtype and menopause. While most studies have focused on postmenopausal hormone receptor-positive disease, less is known about the relationship between obesity and triple-negative breast cancer (TNBC). Here we will review the observations linking obesity to TNBC, the socioeconomic disparities that contribute to obesity-related TNBC, and putative biologic mechanisms. Finally, we will consider the impact of obesity on surgical and medical treatment of TNBC and novel strategies to improve energy balance after cancer diagnosis.

BRCA1/2 pathogenic variants in triple-negative versus luminal-like breast cancers: genotype-phenotype correlation in a cohort of 531 patients

Background

Several available data suggest the association between specific molecular subtypes and BRCA1/2 mutational status. Previous investigations showed the association between BRCA1/2 pathogenic variants (PVs) in specific genomic regions and phenotypic variations of cancer relative risk, while the role of PV type and location in determining the breast cancer (BC) phenotypic features remains still unclear. The aim of this research was to describe the germline BRCA1/2 PVs in triple-negative breast cancer (TNBC) versus luminal-like BC and their potential leverage on BC phenotype.

Patients & methods

We retrospectively collected and analyzed all clinical information of 531 patients with BC genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis at University Hospital Policlinico "P. Giaccone" of Palermo (Sicily) from January 2016 to February 2020.

Results

Our results corroborate the evidence that BRCA1-related tumors often have a profile which resembles the TNBC subtype, whereas BRCA2-associated tumors have a profile that resembles luminal-like BC, especially the Luminal B subtype. Interestingly, our findings suggest that the PVs identified in TNBC were not largely overlapping with those in luminal-like tumors. Differences in the frequency of two PVs potentially associated with different molecular tumor subtypes were observed. BRCA1-633delC was detected with relatively higher prevalence in patients with TNBC, whereas BRCA2-1466delT was found mainly in Luminal B tumors, but in no TNBC patient.

Conclusion

Future studies examining the type and location of BRCA1/2 PVs within different molecular subtypes are required to verify our hypothesis and could provide an interesting insight into the complex topic of genotype-phenotype correlations. Additionally, a more in-depth understanding of the potential correlations between BRCA PVs and clinical and phenotypic features of hereditary BC syndrome patients could be the key to develop better strategies of prevention and surveillance in BRCA-positive carriers without disease.

miR-660-5p promotes breast cancer progression through down-regulating TET2 and activating PI3K/AKT/mTOR signaling

Breast cancer (BC) is a commonly diagnosed cancer in females. MicroRNA-660-5p (miR-660-5p) has been reported to be involved in the occurrence and development of BC. However, the regulatory network of miR-660-5p in BC has not been fully addressed. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the enrichment of miR-660-5p and tet-eleven translocation 2 (TET2) in BC tissues and cells. Cell counting kit-8 (CCK8), flow cytometry, and transwell migration and invasion assays were used to measure cell proliferation, apoptosis, migration, and invasion. The target relationship between miR-660-5p and TET2 was confirmed by dual luciferase reporter assay. Protein expression was measured by western blot. The expression of miR-660-5p was elevated in BC, and high expression of miR-660-5p was closely related to lymph node metastasis, advanced TNM stage, and vascular invasion of BC tumors. miR-660-5p silencing inhibited cell proliferation and metastasis, but induced apoptosis of BC cells. TET2 was identified as a direct target of miR-660-5p, and the interference of TET2 partly reversed the suppressive effects of miR-660-5p silencing on the malignant potential of BC cells. miR-660-5p promoted BC progression partly through modulating TET2 and PI3K/AKT/mTOR signaling. miR-660-5p/TET2 axis might be a promising target for BC treatment.

Therapeutic potential of a novel prodrug of green tea extract in induction of apoptosis via ERK/JNK and Akt signaling pathway in human endometrial cancer

Background

Previous studies have shown a major green tea polyphenol (−)-epigallocatechin-3-gallate ((−)-EGCG) as a powerful anti-cancer agent. However, its poor bioavailability and requirement of a high dosage to manifest activity have restricted its clinical application. Recently, our team synthesized a peracetate-protected derivative of EGCG, which can act as a prodrug of (−)-EGCG (ProEGCG) with enhanced stability and improved bioavailability in vitro and in vivo. Herein, we tested the therapeutic efficacy of this novel ProEGCG, in comparison to EGCG, toward human endometrial cancer (EC).

Methods

In this study, the effects of ProEGCG and EGCG treatments on cell growth, cell survival and modulation of intracellular signaling pathways in RL95–2 and AN3 CA EC cells were compared. The antiproliferative effect was evaluated by cell viability assay. Apoptosis was measured by annexin/propidium iodide staining. Expression of mitogen-activated protein kinases, markers of proliferation and apoptosis were measured by immunoblot analysis. In addition, the effects of ProEGCG and EGCG on tumor growth, vessel formation and gene expression profiles on xenograft models of the EC cells were investigated.

Results

We found that treatment with ProEGCG, but not EGCG, inhibited, in a time- and dose-dependent manner, the proliferation and increased apoptosis of EC cells. Treatment with low-dose ProEGCG significantly enhanced phosphorylation of JNK and p38 MAPK and inhibited phosphorylation of Akt and ERK which are critical mediators of apoptosis. ProEGCG, but not EGCG, elicited a significant decrease in the growth of the EC xenografts, promoted apoptotic activity of tumour cells in the EC xenografts, and decreased microvessel formation, by differentially suppressing anti-apoptotic molecules, NOD1 and NAIP. Notably, no obvious adverse effects were detected.

Conclusions

Taken together, ProEGCG at a low dose exhibited anticancer activity in EC cells through its anti-proliferative, pro-apoptotic and anti-tumor actions on endometrial cancer in vitro and in vivo. In contrast, a low dose of EGCG did not bring about similar effects. Importantly, our data demonstrated the efficacy and safety of ProEGCG which manifests the potential of a novel anticancer agent for the management of endometrial cancer.

Ethyl Acetate Fraction from Hedyotis diffusa plus Scutellaria barbata Exerts Anti-Breast Cancer Effect via miR-200c-PDE7B/PD-L1-AKT/MAPK Axis

Background

Hedyotis diffusa (HD) Willd. and Scutellaria barbata (SB) D. Don in different ratios have been frequently used to treat various cancers in clinical Traditional Chinese Medicine prescriptions. However, the optimal ratio, active fraction, and molecular mechanisms associated with the anti-breast cancer role of this herbal couplet have not been elaborated.

Methods

To screen out the optimal ratio of this herbal couplet, we compare aqueous extracts of HD, SB, or HD plus SB in different weight ratios (HS11, HS12, HS21) for their anticancer effects on murine breast cancer 4T1 cells in vitro and in vivo. EA11, the ethyl acetate fraction from HS11 (the aqueous extract of the couplet at an equal weight ratio), is further assessed for its antiproliferative effect as well as the antitumorigenic impact with the aid of immunocompetent mice. Colony formation, flow cytometry, western blot, ELISA, and qRT-PCR are used to elucidate mechanisms underlying EA11-led effects.

Results

HS11 presents the most potential suppression of 4T1 cell proliferation and tumor growth among these aqueous extracts. The comparison results show that EA11 is more effective than HS11 in vitro and in vivo. EA11 inhibits colony formation and induces apoptosis in a concentration-dependent manner. EA11 reduces the protein expressions of PDE7B, PD-L1, β-catenin, and cyclin D1 while elevating the concentration of cellular cAMP and miR-200c expression in 4T1 cells. Additionally, EA11 exerts its anticancer effect partially via the inactivation of MAPK and AKT signaling pathways.

Conclusions

This study implicates that EA11 prevents breast tumor development by interfering with the miR-200c-PDE7B/PD-L1-AKT/MAPK axis. EA11 may represent a potential therapeutic candidate for breast cancer.

Elucidating the molecular signaling pathways of WAVE3

Cancer metastasis is a complex, multistep process that requires tumor cells to evade from the original site and form new tumors at a distant site or a different organ, often via bloodstream or the lymphatic system. Metastasis is responsible for more than 90% of cancer-related deaths. WAVE3 belongs to the Wiskott-Aldrich syndrome protein (WASP) family, which regulate actin cytoskeleton remodeling as well as several aspects of cell migration, invasion, and metastasis. In fact, WAVE3 has been established as a driver of tumor progression and metastasis in cancers from several origins, including triple negative breast cancers (TNBCs), which are classified as the most lethal subtype of breast cancer, due to their resistance to standard of care therapy and highly metastatic behavior. In this review, we will attempt to summarize the recent advances that have been made to understand how WAVE3 contributes to the molecular mechanisms that control cancer progression and metastasis. We will also review the signaling pathways that are involved in the regulation of WAVE3 expression and function to identify potential therapeutic options targeted against WAVE3 for the treatment of patients with metastatic tumors.

Hereditary Breast and Ovarian Cancer in Families from Southern Italy (Sicily)-Prevalence and Geographic Distribution of Pathogenic Variants in BRCA1/2 Genes

Recent advances in the detection of germline pathogenic variants (PVs) in BRCA1/2 genes have allowed a deeper understanding of the BRCA-related cancer risk. Several studies showed a significant heterogeneity in the prevalence of PVs across different populations. Because little is known about this in the Sicilian population, our study was aimed at investigating the prevalence and geographic distribution of inherited BRCA1/2 PVs in families from this specific geographical area of Southern Italy. We retrospectively collected and analyzed all clinical information of 1346 hereditary breast and/or ovarian cancer patients genetically tested for germline BRCA1/2 PVs at University Hospital Policlinico "P. Giaccone" of Palermo from January 1999 to October 2019. Thirty PVs were more frequently observed in the Sicilian population but only some of these showed a specific territorial prevalence, unlike other Italian and European regions. This difference could be attributed to the genetic heterogeneity of the Sicilian people and its historical background. Therefore hereditary breast and ovarian cancers could be predominantly due to BRCA1/2 PVs different from those usually detected in other geographical areas of Italy and Europe. Our investigation led us to hypothesize that a higher prevalence of some germline BRCA PVs in Sicily could be a population-specific genetic feature of BRCA-positive carriers.

Hierarchical clustering of PI3K and MAPK pathway proteins in breast cancer intrinsic subtypes

The phosphatidylinositol‐3‐kinase (PI3K) and mitogen‐activated protein kinase (MAPK) pathways are frequently activated in breast cancer. We recently demonstrated the importance of analyzing multiple proteins as read‐out for pathway activation in ER+/HER2− breast cancer, since single proteins are known to provide insufficient information. Here, we determined pathway activation in other primary breast cancer intrinsic subtypes derived from postmenopausal patients. Tumor blocks were recollected, and immunohistochemistry was performed using antibodies against PTEN, p‐AKT(Thr308), p‐AKT(Ser473), p‐p70S6K, p‐4EBP1, p‐S6RP(Ser235/236) and p‐ERK1/2, followed by unsupervised hierarchical clustering. In 32 ER+/HER2+, 37 ER−/HER2+ and 74 triple‐negative breast cancer patients, subgroups were identified with preferentially activated (A) and preferentially not activated (N) proteins. These subgroups likely reflect tumors with differences in biological behavior as well as treatment outcome.

Progress in triple negative breast carcinoma pathophysiology: Potential therapeutic targets

Triple-negative breast carcinoma (TNBC) is a subtype of breast carcinoma defined by negativity for estrogen receptor (ER) or progesterone receptor (PR) by immunohistochemical analysis and negativity for human epidermal growth factor receptor (Her2) by immunohistochemistry or in situ hybridization. TNBC is clinically marked by its high aggressiveness, particularly poor outcomes including a low survival rate, and the lack of specific and effective treatments. Therefore, new potential targets for the treatment of TNBC must be identified. This review summarizes recent evidence supporting novel targets and possible therapeutic regimens in the treatment of TNBC.

Rosemary Extract Inhibits Proliferation, Survival, Akt, and mTOR Signaling in Triple-Negative Breast Cancer Cells

Breast cancer is the most commonly diagnosed cancer in women. Triple-negative (TN) breast cancer lacks expression of estrogen receptor (ER), progesterone receptor (PR) as well as the expression and/or gene amplification of human epidermal growth factor receptor 2 (HER2). TN breast cancer is aggressive and does not respond to hormone therapy, therefore new treatments are urgently needed. Plant-derived chemicals have contributed to the establishment of chemotherapy agents. In previous studies, rosemary extract (RE) has been found to reduce cell proliferation and increase apoptosis in some cancer cell lines. However, there are very few studies examining the effects of RE in TN breast cancer. In the present study, we examined the effects of RE on TN MDA-MB-231 breast cancer cell proliferation, survival/apoptosis, Akt, and mTOR signaling. RE inhibited MDA-MB-231 cell proliferation and survival in a dose-dependent manner. Furthermore, RE inhibited the phosphorylation/activation of Akt and mTOR and enhanced the cleavage of PARP, a marker of apoptosis. Our findings indicate that RE has potent anticancer properties against TN breast cancer and modulates key signaling molecules involved in cell proliferation and survival.

Metabolic Health, Insulin, and Breast Cancer: Why Oncologists Should Care About Insulin

Studies investigating the potential link between adult pre-menopausal obesity [as measured by body mass index (BMI)] and triple-negative breast cancer have been inconsistent. Recent studies show that BMI is not an exact measure of metabolic health; individuals can be obese (BMI > 30 kg/m²) and metabolically healthy or lean (BMI < 25 kg/m²) and metabolically unhealthy. Consequently, there is a need to better understand the molecular signaling pathways that might be activated in individuals that are metabolically unhealthy and how these signaling pathways may drive biologically aggressive breast cancer. One key driver of both type-2 diabetes and cancer is insulin. Insulin is a potent hormone that activates many pathways that drive aggressive breast cancer biology. Here, we review (1) the controversial relationship between obesity and breast cancer, (2) the impact of insulin on organs, subcellular components, and cancer processes, (3) the potential link between insulin-signaling and cancer, and (4) consider time points during breast cancer prevention and treatment where insulin-signaling could be better controlled, with the ultimate goal of improving overall health, optimizing breast cancer prevention, and improving breast cancer survival.

Expression of Bioinformatically Candidate miRNAs including, miR-576-5p, miR-501-3p and miR-3143, Targeting PI3K Pathway in Triple-Negative Breast Cancer

Background

Triple-negative breast cancer (TNBC) is an invasive and lethal form of breast cancer. PI3K pathway, which often activated in TNBC patients, can be a target of miRNAs. The purpose of this study was bioinformatic prediction of miRNAs targeting the key genes of this pathway and evaluation of the expression of them and their targets in TNBC.

Materials and Methods

We predicted miRNAs targeting PIK3CA and AKT1 genes using bioinformatics tools. Extraction of total RNA, synthesis of cDNA and quantitative real-time polymerase chain reaction were performed from 18 TNBC samples and normal adjacent tissues and cell lines.

Results

Our results demonstrated that miR-576-5p, miR-501-3p and miR-3143 were predicted to target PIK3CA, AKT1 and both of these mRNAs, respectively and were down-regulated while their target mRNAs were up-regulated in clinical samples and cell lines. The analysis of the receiver operating characteristic curve was done for the evaluation of the diagnostic value of predicted miRNAs in TNBC patients.

Conclusion

The findings of our study demonstrated the reverse correlation between miRNAs and their target genes and therefore the possibility of these miRNAs to be proposed as new candidates for TNBC targeted therapies.

Total saponins of Bolbostemma paniculatum (maxim.) Franquet exert antitumor activity against MDA-MB-231 human breast cancer cells via inhibiting PI3K/Akt/mTOR pathway

BACKGROUND

The aim of the present study was to examine the effects of the Bolbostemma paniculatum (Maxim.) Franquet (BP) active compound, BP total saponins (BPTS), on MDA-MB-231 cells, and investigate the underlying mechanism regarding BPTS-mediated attenuation of the PI3K/Akt/mTOR pathway.

METHODS

The effect of BPTS on cytotoxicity, induction of apoptosis and migration on MDA-MB-231 cells at three different concentrations was investigated. A CCK-8 assay, wound-healing assay and flow cytometry were used to demonstrate the effects of BPTS. Additionally, expression of the primary members of the PI3K/Akt/mTOR signaling pathway was assessed using western blotting. To verify the underlying mechanisms, a PI3K inhibitor and an mTOR inhibitor were used.

RESULTS

BPTS inhibited proliferation of MDA-MB-231 cells with an IC50 value of 10 μg/mL at 48 h. BPTS inhibited migration of MDA-MB-231 cells, and the western blot results demonstrated that BPTS reduced p-PI3K, p-Akt and p-mTOR protein expression levels in MDA-MB-231 cells. Additionally, the results were confirmed using a PI3K inhibitor and an mTOR inhibitor. BPTS decreased proliferation and migration of MDA-MB-231 cells possibly through inhibiting the PI3K/Akt/mTOR signaling pathway.

CONCLUSIONS

The results highlight the therapeutic potential of BPTS for treating patients with triple-negative breast cancer.

Investigating the regulation mechanism of baicalin on triple negative breast cancer's biological network by a systematic biological strategy

OBJECTIVE

To investigate the regulation mechanism of baicalin on triple negative breast cancer (TNBC)'s biological network by a systematic biological strategy and cytology experiment.

METHODS

A systematic biological methodology is utilized to predict the potential targets of baicalin, collect the genes of TNBC, and analyze the TNBC and baicalin's network. After the systematic biological analysis is performed, the cytology experiment, real-time quantitative PCR (qPCR) is used to validate the key biological processes and signaling pathways.

RESULTS

After systematic biological analysis, two networks were constructed and analyzed: (1) TNBC network; (2) Baicalin-TNBC protein-protein interaction (PPI) network. Several TNBC-related, treatment-related targets, clusters, signaling pathways and biological processes were found. Cytology experiment shows that baicalin can inhibit the proliferation, migration and invasion of breast cancer MDA-MB-231 cells in vitro (P < 0.05). The results of qPCR showed that baicalin increase the expression of E-cadherin mRNA, and decrease the expression of vimentin, β-catenin, c-Myc and MMP-7 mRNA in LPS-induced breast cancer MDA-MB-231 cells (P < 0.05).

CONCLUSION

Baicalin may achieve anti-tumor effects through regulating the targets, biological processes and pathways found in this research.

Advances in Targeted Therapies for Triple-Negative Breast Cancer

While the outcomes for patients diagnosed with hormone receptor positive (HR+) and/or human epidermal growth factor receptor 2-positive (HER2+) breast cancers have continued to improve with the development of targeted therapies, the same cannot be said yet for those affected with triple-negative breast cancer (TNBC). Currently, the mainstay of treatment for the 10-15% of patients diagnosed with TNBC remains cytotoxic chemotherapy, but it is hoped that through an enhanced characterization of TNBC biology, this disease will be molecularly delineated into subgroups with targetable oncogenic drivers. This review will focus on recent therapeutic innovations for TNBC, including poly-ADP-ribosyl polymerase (PARP) inhibitors, phosphoinositide 3-kinase (PI3K) pathway inhibitors, immune checkpoint inhibitors, and cyclin-dependent kinase (CDK) inhibitors.

Targeting the complexity of Src signalling in the tumour microenvironment of pancreatic cancer: from mechanism to therapy

Pancreatic cancer, a disease with extremely poor prognosis, has been notoriously resistant to virtually all forms of treatment. The dynamic crosstalk that occurs between tumour cells and the surrounding stroma, frequently mediated by intricate Src/FAK signalling, is increasingly recognised as a key player in pancreatic tumourigenesis, disease progression and therapeutic resistance. These important cues are fundamental for defining the invasive potential of pancreatic tumours, and several components of the Src and downstream effector signalling have been proposed as potent anticancer therapeutic targets. Consequently, numerous agents that block this complex network are being extensively investigated as potential antiinvasive and antimetastatic therapeutic agents for this disease. In this review, we will discuss the latest evidence of Src signalling in PDAC progression, fibrotic response and resistance to therapy. We will examine future opportunities for the development and implementation of more effective combination regimens, targeting key components of the oncogenic Src signalling axis, and in the context of a precision medicine-guided approach.

Downregulation of GATS gene inhibits proliferation, clonogenicity and migration in triple negative breast cancer cells MDA-MB-231 by cell autophagy

The triple negative breast cancer (TNBC) accounts for 15% to 20% of the total number of breast cancer diagnosed. A number of clinical studies have shown that TNBC has a high risk of early recurrence and distant metastasis, and a low rate of disease free survival and total survival. The premise of TNBC deterioration was abnormal proliferation and migration of tumor cells, and this study firstly showed that GATS gene could promote proliferation of MDA-MB-231 breast cancer cells. Through lentiviral expression system, the GATS gene was konckdown by shGATS lentivirus infection in the MDA-MB-231 cells, and the result indicated it could remarkably decrease the ability of cell proliferation and migration. Real-time PCR, western blot and immunofluorescence experiments showed the expressions of protein LC3, and p-Akt in shGATS cell group were lower than the shCtrl group. Therefore, we suggest the GATS could promote the MDA-MB-231 cell proliferation, migration and clonogenicity through cell autophagy by the PI3K/Akt pathway, which paved the way for further study the function of GATS in TNBC, and GATS may potentially be a target for gene therapy against triple negative breast cancer.

Weighted correlation network analysis of triple-negative breast cancer progression: Identifying specific modules and hub genes based on the GEO and TCGA database

Triple-negative breast cancer (TNBC) represents an aggressive malignancy of frequent high histologic grade with no effective specific targeted therapies. The present study aimed to identify specific modules and hub genes that may influence the progression of TNBC. The key words ‘breast cancer’ were used to search microarray datasets in the Gene Expression Omnibus and The Cancer Genome Atlas databases that included 5 datasets. A total of 11 co-expression modules were constructed based on the expression levels of 5,782 genes obtained from 456 patients with TNBC using the weighted correlation network analysis (WGCNA). The results demonstrated that the red module was significantly associated with relapse-free survival (RFS) in patients with TNBC [hazard ratio (HR)=0.381, 95% confidence interval (CI), 0.183–0.793; P=0.010]. The functional enrichment analysis revealed that the biological processes corresponding to the red module were ‘mRNA processing’, ‘histone lysine methylation’ and ‘regulation of TOR signaling’. In addition, Hedgehog signaling pathways were considered to serve a critical role in the development of this disease (P<0.001). A total of 12 hub genes were identified, of which α-thalassemia/mental retardation syndrome X-linked (ATRX) was significantly associated with RFS in patients with TNBC (HR=0.601; 95%CI, 0.376–0.960; P=0.033). The receiver operating characteristic curve indicated that ATRX could distinguish relapse from non-relapse in patients with TNBC (area under the curve=0.570; P=0.023). In conclusion, the present study demonstrated that ATRX was associated with TNBC progression, which suggested that ATRX may be involved in a recombination-mediated telomere maintenance mechanism.