Signal Transduction Pathways in Breast Cancer: The Important Role of PI3K/Akt/mTOR

Combination of monensin and erlotinib synergistically inhibited the growth and cancer stem cell properties of triple-negative breast cancer by simultaneously inhibiting EGFR and PI3K signaling pathways

BACKGROUND

Cancer stem cells (CSCs) in triple-negative breast cancer (TNBC) are recognized as a highly challenging subset of cells, renowned for their heightened propensity for relapse and unfavorable prognosis. Monensin, an ionophoric antibiotic, has been reported to exhibit significant therapeutic efficacy against various cancers, especially CSCs. Erlotinib is classified as one of the EGFR-TKIs and has been previously identified as a promising therapeutic target for TNBC. Our research aims to assess the effectiveness of combination of monensin and erlotinib as a potential treatment strategy for TNBC.

METHODS

The combination of monensin and erlotinib was assessed for its potential anticancer activity through various in vitro assays, including cytotoxicity assay, colony formation assay, wound healing assay, transwell assay, mammosphere formation assay, and proportion of CSCs assay. Additionally, an in vivo study using tumor-bearing nude mice was conducted to evaluate the inhibitory effect of the monensin and erlotinib combination on tumor growth.

RESULTS

The results indicated that combination of monensin with erlotinib synergistically inhibited cell proliferation, the migration rate, the invasion ability and decreased the CSCs proportion, and CSC markers SOX2 and CD133 in vivo and in vitro. Furthermore, the primary proteins involved in the signaling pathways of the EGFR/ERK and PI3K/AKT are simultaneously inhibited by the combination treatment of monensin and erlotinib in vivo and in vitro.

CONCLUSIONS

The simultaneous inhibition of the EGFR/ERK and PI3K/AKT/mTOR signaling pathways by the combination of monensin and erlotinib exhibited a synergistic effect on suppressing tumor proliferation and cancer cell stemness in TNBC.

Inhibition of glycolysis and Src/Akt signaling reduces Caveolin-1-enhanced metastasis

Metastasis is the leading cause of cancer-related deaths, making the development of novel, more effective therapies imperative to alleviate patient suffering. Metabolic switching is a hallmark of cancer cells that facilitates metastasis. Cancer cells obtain most of their energy and intermediate metabolites, which are required to proliferate and metastasize, through aerobic glycolysis. Previous work from our laboratory has shown that Caveolin-1 (CAV1) expression in cancer cells promotes glycolysis and metastasis. Here, we sought to determine if limiting glycolysis reduced CAV1-enhanced metastasis and to identify the mechanism(s) involved. We evaluated the effects of the glycolysis inhibitor 2-deoxy-D-glucose (2-DG) in metastatic melanoma and breast cancer cell lines expressing or not CAV1. Non-cytotoxic concentrations of 2-DG (1 mM) inhibited the migration of B16-F10 melanoma and MDA-MB-231 breast cancer cells. CAV1-mediated activation of Src/Akt signaling was required for CAV1-enhanced migration and was blocked in the presence of 2-DG. Moreover, inhibition of Akt reduced CAV1-enhanced lung metastasis of B16-F10 cells. Collectively, these findings highlight the importance of CAV1-induced metabolic reprogramming for metastasis and point towards possible therapeutic approaches to prevent metastatic disease by inhibiting glycolysis and Src/Akt signaling.

Exploration and biological evaluation of 20-vinyl pregnenes: A step forward toward selective modulators of the estrogen receptor α signaling for breast cancer treatment

A series of D-ring modified steroids bearing a vinyl ketone pendant were synthesized and evaluated for antiproliferative activity against breast cancer cell line and cytochromes P450. The lead compound, 21-vinyl 20-keto-pregnene (2f) (IC50 = 2.4 µM), was shown to be a promising candidate for future anticancer drug design, particularly against estrogen receptor α (ERα)-positive breast cancer. The lead compound was found to have a significant effect on the signaling pathways in parental and 4-hydroxytamoxifen-resistant cells. Compound 2f modulated the ERK, cyclin D1, and CDK4 pathways and blocked the expression of ERα, the main driver of breast cancer growth. Compound 2f significantly reduced 17β-estradiol-induced progesterone receptor expression. Accumulation of cleaved poly(ADP-ribose) polymerase in cells treated with compound 2f indicated induction of apoptosis. The selectivity analysis showed that lead compound 2f produces no significant effects on cytochromes P450, CYP19A1, CYP21A2, and CYP7B1.

Shared genetics between breast cancer and predisposing diseases identifies novel breast cancer treatment candidates

Background

Current effective breast cancer treatment options have severe side effects, highlighting a need for new therapies. Drug repurposing can accelerate improvements to care, as FDA-approved drugs have known safety and pharmacological profiles. Some drugs for other conditions, such as metformin, an antidiabetic, have been tested in clinical trials for repurposing for breast cancer. Here, we exploit the genetics of breast cancer and linked predisposing diseases to propose novel drug repurposing. We hypothesize that if a predisposing disease contributes to breast cancer pathology, identifying the pleiotropic genes related to the risk of cancer could prioritize drug targets, among all drugs treating a predisposing disease. We aim to develop a method to not only prioritize drug repurposing, but also to highlight shared etiology explaining repurposing.

Methods

We compile breast cancer's predisposing diseases from literature. For each predisposing disease, we use GWAS summary statistics to identify genes in loci showing genetic correlation with breast cancer. Then, we use a network approach to link these shared genes to canonical pathways, and similarly for all drugs treating the predisposing disease, we link their targets to pathways. In this manner, we are able to prioritize a list of drugs based on each predisposing disease, with each drug linked to a set of implicating pathways. Finally, we evaluate our recommendations against drugs currently under investigation for breast cancer.

Results

We identify 84 loci harboring mutations with positively correlated effects between breast cancer and its predisposing diseases; these contain 194 identified shared genes. Out of the 112 drugs indicated for the predisposing diseases, 76 drugs can be linked to shared genes via pathways (candidate drugs for repurposing). Fifteen out of these candidate drugs are already in advanced clinical trial phases or approved for breast cancer (OR = 9.28, p = 7.99e-03, one-sided Fisher's exact test), highlighting the ability of our approach to identify likely successful candidate drugs for repurposing.

Conclusions

Our novel approach accelerates drug repurposing for breast cancer by leveraging shared genetics with its known risk factors. The result provides 59 novel candidate drugs alongside biological insights supporting each recommendation.

Investigating the potential of mono-chalcone compounds in targeting breast cancer receptors through network pharmacology, molecular docking, molecular dynamics simulation, antiproliferative effects, and gene expressions

The study aims to investigate various aspects of synthesized mono-chalcone compounds 5 and 8 concerning breast cancer, including network pharmacology, molecular docking, molecular dynamics (MD) simulations, antiproliferative effects, and gene expressions. Initially, the compounds underwent a network pharmacology analysis targeting breast cancer-related targets, with MalaCards, SwissTargetPrediction, and PharmMapper identifying 70 breast cancer target receptors. Subsequently, protein-protein interaction (PPI) network analysis revealed two distinct target gene clusters. Survival analysis identified seven significant target genes following Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and Gene Ontology (GO) evaluation. Molecular docking and MD simulations were conducted on these seven target genes (AKT2, BRAF, ESR1, FGFR1, IGF1, IGF1R, and KIT), revealing that compound 8 exhibited the highest binding affinities, as well as better stability and compactness when interacting with the targeted proteins. Next, the compounds underwent cell viability assay and gene expression analysis to validate the in silico findings. Both compounds demonstrated the ability to suppress breast cancer proliferation, with compound 8 showing increased selectivity in targeting breast cancer cells while causing minimal harm to normal breast cells. The suppression of breast cancer cell proliferation was attributed to decreased expression levels of AKT2, BRAF, FGFR1, IGF1, IGF1R, KIT, and ESR1. Hence, the results provide insights into the molecular interaction responsible for the anti-breast cancer capabilities of mono-chalcone compounds.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03991-y.

DEAR model in overweight endometrial cancer patients undergoing fertility-sparing treatment: A randomized controlled trial

OBJECTIVE

To evaluate the effects of DEAR weight management in overweight patients undergoing fertility-sparing treatment for endometrial cancer or atypical hyperplasia.

METHODS

Women with endometrial cancer or atypical hyperplasia who received fertility-sparing treatment and had a body mass index of >25 kg/m2 were randomly allocated to the DEAR (DEAR weight management) and control (self weight management) groups. Body morphology and composition, glycolipid metabolism, and tumor outcomes were assessed in both groups before and at 3 and 6 months after intervention.

RESULTS

Overall, 72 subjects were included (36 in each group). Following intervention, the DEAR group showed significantly lower median body weight (69.45 vs. 78.05), body mass index (26.19 vs. 29.15), lipid accumulation index (29.21 vs. 57.86), body fat mass (24.00 vs. 29.30), visceral fat area (112.5 vs. 133.3), and glycolipid metabolic indices (except high density lipoprotein) than the control group (P < 0.05) and showed a decreasing trend. The test group achieved significantly higher complete remission (88.46% vs. 57.14%; P < 0.05); the time to complete remission did not differ significantly (P > 0.05).

CONCLUSIONS

DEAR weight management can improve the studied parameters and complete remission rates in this population.

REGISTRATION

NCT06169449.

Piperlongumine: the amazing amide alkaloid from Piper in the treatment of breast cancer

Piperlongumine (PL), an alkaloid found primarily in the fruits and roots of the plant Piper longum L. (Piperaceae), is a natural compound that exhibits potent activity against various cancer cell proliferation. The most frequently caused malignancy in women globally, breast cancer (BC), has been demonstrated to be significantly inhibited by PL. Apoptosis, cell cycle arrest, increased ROS generation, and changes in the signalling protein's expression are all caused by the numerous signalling pathways that PL impacts. Since BC cells resist conventional chemotherapeutic drugs (doxorubicin, docetaxel etc.), researchers have shown that the drugs in combination with PL can exhibit a synergistic effect, greater than the effects of the drug or PL alone. Recently, techniques for drug packaging based on nanotechnology have been employed to improve PL release. The review has presented an outline of the chemistry of PL, its molecular basis in BC, its bioavailability, toxicity, and nanotechnological applications. An attempt to understand the future prospects and direction of research about the compound has also been discussed.

Transcriptomic analysis revealed potential regulatory biomarkers and repurposable drugs for breast cancer treatment

Breast cancer (BC) is the most widespread cancer worldwide. Over 2 million new cases of BC were identified in 2020 alone. Despite previous studies, the lack of specific biomarkers and signaling pathways implicated in BC impedes the development of potential therapeutic strategies. We employed several RNAseq datasets to extract differentially expressed genes (DEGs) based on the intersection of all datasets, followed by protein-protein interaction network construction. Using the shared DEGs, we also identified significant gene ontology (GO) and KEGG pathways to understand the signaling pathways involved in BC development. A molecular docking simulation was performed to explore potential interactions between proteins and drugs. The intersection of the four datasets resulted in 146 DEGs common, including AURKB, PLK1, TTK, UBE2C, CDCA8, KIF15, and CDC45 that are significant hub-proteins associated with breastcancer development. These genes are crucial in complement activation, mitotic cytokinesis, aging, and cancer development. We identified key microRNAs (i.e., hsa-miR-16-5p, hsa-miR-1-3p, hsa-miR-147a, hsa-miR-195-5p, and hsa-miR-155-5p) that are associated with aggressive tumor behavior and poor clinical outcomes in BC. Notable transcription factors (TFs) were FOXC1, GATA2, FOXL1, ZNF24 and NR2F6. These biomarkers are involved in regulating cancer cell proliferation, invasion, and migration. Finally, molecular docking suggested Hesperidin, 2-amino-isoxazolopyridines, and NMS-P715 as potential lead compounds against BC progression. We believe that these findings will provide important insight into the BC progression as well as potential biomarkers and drug candidates for therapeutic development.

BRCA Mutations and MicroRNA Expression Patterns in the Peripheral Blood of Breast Cancer Patients

Breast cancer (BC) persists as the predominant malignancy globally, standing as the foremost cause of cancer-related mortality among women. Despite notable advancements in prevention and treatment, encompassing the incorporation of targeted immunotherapies, a continued imperative exists for the development of innovative methodologies. These methodologies would facilitate the identification of women at heightened risk, enhance the optimization of therapeutic approaches, and enable the vigilant monitoring of emergent treatment resistance. Circulating microRNAs (miRNAs), found either freely circulating in the bloodstream or encapsulated within extracellular vesicles, have exhibited substantial promise for diverse clinical applications. These applications range from diagnostic and prognostic assessments to predictive purposes. This study aimed to explore the potential associations between BRCA mutations and specific miRNAs (miR-21, miR-155, miR-126, and miR-200c) expression that are known to be dysregulated in BC patient samples. Our findings indicate a robust correlation between miRNA expression status and disease subtypes. We found a correlation between the expression status of miRNAs and distinct disease subtypes. Intriguingly, however, no significant associations were discerned between disease status, subtypes, or miRNA expression levels and the presence of BRCA mutations. To advance the validation of miRNAs as clinically relevant biomarkers, additional investigations within larger and meticulously selected patient cohorts are deemed imperative. These microRNA entities hold the potential to emerge as groundbreaking and readily accessible tools, poised for seamless integration into the landscape of clinical practice.

Endosomal recycling inhibitors downregulate estrogen receptor-alpha and synergise with endocrine therapies

PURPOSE

Breast cancer (BC) accounts for roughly 30% of new cancers diagnosed in women each year; thus, this cancer type represents a substantial burden for people and health care systems. Despite the existence of effective therapies to treat BC, drug resistance remains a problem and is a major cause of treatment failure. Therefore, new drugs and treatment regimens are urgently required to overcome resistance. Recent research indicates that inhibition of the endosomal recycling pathway, an intracellular membrane trafficking pathway that returns endocytosed proteins back to the plasma membrane, may be a promising strategy to downregulate clinically relevant cell surface proteins such as HER2 and HER3, and to overcome drug resistance.

METHODS

To investigate the molecular mechanism of action of an endosomal recycling inhibitor (ERI) called primaquine, we performed a reverse-phase protein array (RPPA) assay using a HER2-positive breast cancer cell line. The RPPA findings were confirmed by Western blot and RT-qPCR in several BC cell lines. Novel drug combinations were tested by MTT cell viability and clonogenic assays.

RESULTS

Among the signalling molecules downregulated by ERIs were estrogen receptor-alpha (ER-α) and androgen receptor. We confirmed this finding in other breast cancer cell lines and show that downregulation occurs at the transcriptional level. We also found that ERIs synergise with tamoxifen, a standard-of-care therapy for breast cancer.

DISCUSSION

Our data suggest that combining ERIs with hormone receptor antagonists may enhance their efficacy and reduce the emergence of drug resistance.

Inhibition of cancer cells by Quinoline-Based compounds: A review with mechanistic insights

This article includes a thorough examination of the inhibitory potential of quinoline-based drugs on cancer cells, as well as an explanation of their modes of action. Quinoline derivatives, due to their various chemical structures and biological activity, have emerged as interesting candidates in the search for new anticancer drugs. The review paper delves into the numerous effects of quinoline-based chemicals in cancer progression, including apoptosis induction, cell cycle modification, and interference with tumor-growth signaling pathways. Mechanistic insights on quinoline derivative interactions with biological targets enlightens their therapeutic potential. However, obstacles such as poor bioavailability, possible off-target effects, and resistance mechanisms make it difficult to get these molecules from benchside to bedside. Addressing these difficulties might be critical for realizing the full therapeutic potential of quinoline-based drugs in cancer treatment.

Protective Effect of Whole Wheat on Muscle Atrophy in C2C12 Cells via Akt/FoxO1 Signaling Pathways

Skeletal muscles are important for body movement, postural maintenance, and energy metabolism. Muscle atrophy is caused by various factors, including lack of exercise, age, genetics, and malnutrition, leading to the loss of muscle mass. The Akt/FoxO signaling pathway plays a key role in the regulation of muscle protein synthesis and degradation. Whole wheat contains functional ingredients that may indirectly contribute to muscle health and function and can help prevent or slow the progression of muscle atrophy. In this study, the protective effects of three wheat cultivars (Seodun, Ol, and Shinmichal 1) against hydrogen peroxide-induced muscle atrophy in C2C12 cells were investigated. We found that whole-wheat treatment reduced reactive oxygen species production, prevented glutathione depletion, and increased myotube diameter, thereby reducing muscle atrophy by activating myoblast differentiation. Generally, "Shinmichal 1" exhibited the highest activation of the Akt/FoxO signaling pathway. In contrast, "Seodun" showed similar or slightly higher activities than those of the H2O2-treated only group. In conclusion, whole wheat exerts a protective effect against muscle atrophy by activating the Akt/FoxO signaling pathway. This study indicates that whole wheat may help prevent muscle atrophy.

Non-coding RNAs mediated inflammation in breast cancers

Breast cancer is the major cancer that affects women all over the world. The awareness over past several decades has led to intensive screening and detection as well as successful treatments. Still, the breast cancer mortality is unacceptable and needs to be urgently addressed. Among many factors, inflammation has often been associated with tumorigenesis, including breast cancer. More than a third of all breast cancer deaths are marked by deregulated inflammation. The exact mechanisms are still not completely known but among the many putative factors, the epigenetic changes, particularly those mediated by non-coding RNAs are fascinating. microRNAs, long non-coding RNAs as well as circular RNAs seem to impact the inflammation in breast cancer which further highlights their important regulatory role in breast cancer pathogenesis. Understanding inflammation in breast cancer and its regulation by non-coding RNAs is the primary objective of this review article. We attempt to provide the most complete information on the topic in hopes of opening new areas of research and discoveries.

Correlation of PTEN signaling pathway and miRNA in breast cancer

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

CRISPR-based therapeutic targeting of signaling pathways in breast cancer

Breast cancer remains a leading cause of death for women worldwide, and new treatment strategies are needed. There are innumerable anomalous genes that are responsible for the multi-factorial carcinogenesis pathway. Although several disease-causing mutations have been detected, therapy frequently focuses on attenuating the manifestation of the disease rather than harmonizing the mutation in the target area. The advent of CRISPR-Cas9 technology has revolutionized genome editing, allowing for precise and efficient manipulation of gene expression. The purpose of this review paper is to summarize recent progress in the use of CRISPR-based approaches to target key signaling pathways associated with breast cancer progression. The first section introduces basic concepts of CRISPR technology, focusing on its application in genome editing and transcriptional regulation followed by an overview of aspects involving complex signaling pathways in breast cancer such as P13K/AKT/mTOR, EPK/MAPK and Wnt/β catenin. An extensive literature search using PubMed and Google Scholar is performed for information retrieval. Further, the role of CRISPR-based interventions in regulating gene expression revealed, altered pathway activity and potential therapeutic consequences are discussed. This review will be a valuable addition to providing comprehensive knowledge of CRISPR-Cas-mediated therapeutic targeting in breast cancer.

MiR-150-5p contributes to unexplained recurrent spontaneous abortion by targeting VEGFA and downregulating the PI3K/AKT/mTOR signaling pathway

PURPOSE

The purpose of this study is to investigate the function of miR-150-5p in URSA.

METHOD

Twenty-six chorionic villous tissues were collected to examine the expression of miR-150-5p and VEGFA by using quantitative polymerase chain reaction (qPCR) and western blot assay, respectively. Transwell assay was conducted to assess the migration and invasion ability of trophoblast cells. The dual-luciferase reporter assay was applied to determine the relationship between miR-150-5p and VEGFA in vitro. Relevant signaling pathway protein expression level was measured via western blot assay. Signaling transduction inhibitor LY294002 was used to block PI3K/AKT/mTOR signaling pathway. Finally, in vivo the effect of miR-150-5p on embryonic absorption rate was evaluated in mice.

RESULTS

Clinical samples revealed that miR-150-5p expression was significantly elevated in the villous tissues and serum of URSA patients. Moreover, the overexpressing of miR-150-5p could inhibit both HTR-8/SVneo cell and JAR cell migration, invasion, and restrained PI3K/AKT/mTOR signaling pathway by targeting VEGFA in vitro. This inhibitory effect of miR-150-5p could be reversed by overexpressing the gene of vascular epithelial growth factor A (VEGFA). In contrary, inhibition of miR-150-5p significantly enhanced migration, invasion ability of both HTR-8/SVneo and JAR cells, and also could stimulate PI3K/AKT/mTOR signaling pathway. This promoting effect of miR-150-5p could be ameliorated by LY294002 (PI3K inhibitor). Finally, after miR-150-5p overexpression in vivo, the embryo resorption rate in pregnant mice was increased significantly.

CONCLUSIONS

Overall, these findings imply that miR-150-5p is among the key factors that regulate the pathogenesis of URSA.

The role of miR-133a in silibinin-mediated inhibition of the PI3K/AKT/mTOR pathway in MCF-7 breast carcinoma cells

Breast cancer is particularly severe in women. Research highlights the crucial role of miRNAs in key cellular processes, showcasing their intricate interactions with the oncogenic PI3K/AKT/mTOR (PAM) signaling pathway and underscoring their significant role as tumor suppressors. The effect of silibinin on cell growth and survival was evaluated using an MTT assay. Bioinformatics analysis identified putative miR-133a targets inside the PAM pathway. After incubating MCF-7 cells with silibinin, we measured miR-133a, EGFR, PI3K, AKT, PTEN, and mTOR expression levels using qRT-PCR. Furthermore, protein expression levels of mTOR were assessed using Western blotting. The MTT experiment displayed that silibinin effectively inhibits MCF-7 cell proliferation in a time- and dose-dependent manner. Silibinin's IC50 value, determined at 370 μM after 48 hours, was established. qRT-PCR analysis at this IC50 concentration highlighted reduced expression of EGFR, PI3K, AKT, PTEN, and mTOR mRNAs, alongside increased miR-133a expression. Notably, miR-133a exhibited a negative correlation with both EGFR and PIK3C2A expression. Furthermore, western blotting confirmed silibinin's capacity to diminish p-mTOR protein levels, the ultimate element of the PAM signaling pathway. The findings enhance comprehension of silibinin's impact on PAM signaling and miR-133a expression, offering promise for targeted therapies in disrupting oncogenic pathways in MCF-7 breast cancer cells. This insight could advance breast cancer treatment strategies.

The Anticancer Effects of Marine Carotenoid Fucoxanthin through Phosphatidylinositol 3-Kinase (PI3K)-AKT Signaling on Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks specific targets such as estrogen, progesterone, and HER2 receptors. TNBC affects one in eight women in the United States, making up 15-20% of breast cancer cases. Patients with TNBC can develop resistance to chemotherapy over time, leading to treatment failure. Therefore, finding other options like natural products is necessary for treatment. The advantages of using natural products sourced from plants as anticancer agents are that they are less toxic, more affordable, and have fewer side effects. These products can modulate several cellular processes of the tumor microenvironment, such as proliferation, migration, angiogenesis, cell cycle arrest, and apoptosis. The phosphatidyl inositol 3-kinase (PI3K)-AKT signaling pathway is an important pathway that contributes to the survival and growth of the tumor microenvironment and is associated with these cellular processes. This current study examined the anticancer effects of fucoxanthin, a marine carotenoid isolated from brown seaweed, in the MDA-MB-231 and MDA-MB-468 TNBC cell lines. The methods used in this study include a cytotoxic assay, PI3K-AKT signaling pathway PCR arrays, and Wes analysis. Fucoxanthin (6.25 µM) + TNF-α (50 ng/mL) and TNF-α (50 ng/mL) showed no significant effect on cell viability compared to the control in both MDA-MB-231 and MDA-MB-468 cells after a 24 h treatment period. PI3K-AKT signaling pathway PCR array studies showed that in TNF-α-stimulated (50 ng/mL) MDA-MB-231 and MDA-MB-468 cells, fucoxanthin (6.25 µM) modulated the mRNA expression of 12 genes, including FOXO1, RASA1, HRAS, MAPK3, PDK2, IRS1, EIF4EBP1, EIF4B, PTK2, TIRAP, RHOA, and ELK1. Additionally, fucoxanthin significantly downregulated the protein expression of IRS1, EIF4B, and ELK1 in MDA-MB-231 cells, and no change in the protein expression of EIF4B and ELK1 was shown in MDA-MB-468 cells. Fucoxanthin upregulated the protein expression of RHOA in both cell lines. The modulation of the expression of genes and proteins of the PI3K-AKT signaling pathway may elucidate fucoxanthin's effects in cell cycle progression, apoptotic processes, migration, and proliferation, which shows that PI3K-AKT may be the possible molecular mechanism for fucoxanthin's effects. In conclusion, the results obtained in this study elucidate fucoxanthin's molecular mechanisms and indicate that fucoxanthin may be considered a promising candidate for breast cancer-targeted therapy.

LncRNA MALAT1 Expression Regulates Breast Cancer Progression via PI3K/AKT/mTOR Pathway Modulation

Breast cancer is a significant health challenge for women globally, including the Pakistani population. Numerous pathways and small molecules like noncoding ribonucleotides are implicated in breast cancer development and progression. Among these, lncRNAs, have garnered considerable attention due to their role in breast cancer tumorigenesis and metastasis. In the current study involving 52 mammary tumor samples from the Pakistani population, the expression of lncRNA MALAT1 (metastasis associated lung adenocarcinoma transcript 1) was studied via RT-PCR (Real-Time polymerase chain reaction). In addition, PI3K/AKT/mTOR pathway expression was also assessed through RT-PCR and immunohistochemistry in breast cancer patient samples. The study also investigated the cross-talk of lncRNA MALAT1 and PI3K pathway genes by inhibiting it with PI3K inhibitor (LY294002) in MDA-MB-231 cell line. Furthermore, lncRNA MALAT1 was silenced in MDA-MB-231 cells using siRNA to determine its impact on breast cancer proliferation and metastasis. The results revealed an upregulated expression of MALAT1 and PI3K/AKT/mTOR pathway genes in grade II and III breast tissue samples before chemotherapy. The proliferation, growth, and invasion of breast cancer cells were significantly reduced upon MALAT1 silencing in MDA-MB-231. Further, its downregulation substantially reduced the PI3K pathway expression levels at mRNA and protein levels. In conclusion, the current study suggests that MALAT1 could serve as a therapeutic target for breast cancer, underscoring its role in breast cancer proliferation and metastasis. Moreover, the study proposes a mechanism of action of MALAT1, demonstrating that its inhibition can reduce the expression of the PI3K/AKT/mTOR axis. These findings emphasize the potential significance of targeting MALAT1 as a therapeutic strategy for breast cancer, and further exploration of this interaction is warranted to gain deeper insight into the molecular mechanism of this lncRNA.

A review of biological targets and therapeutic approaches in the management of triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous, aggressive phenotype of breast cancer with associated chemoresistance. The development of chemo- or radioresistance could be attributed to diverse tumor microenvironments, overexpression of membrane proteins (transporters), epigenetic changes, and alteration of the cell signaling pathways/genes associated with the development of cancer stem cells (CSCs).

AIM OF REVIEW

Due to the diverse and heterogeneous nature of TNBC, therapeutic response to the existing modalities offers limited scope and thus results in reccurance after therapy. To establish landmark therapeutic efficacy, a number of novel therapeutic modalities have been proposed. In addition, reversal of the resistance that developed during treatment may be altered by employing appropriate therapeutic modalities. This review aims to discuss the plethora of investigations carried out, which will help readers understand and make an appropriate choice of therapy directed toward complete elimination of TNBC.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This manuscript addresses the major contributory factors from the tumor microenvironment that are responsible for the development of chemoresistance and poor prognosis. The associated cellular events and molecular mechanism-based therapeutic interventions have been explained in detail. Inhibition of ABC transporters, cell signaling pathways associated with CSCs, and epigenetic modification offers promising results in this regard. TNBC progression, invasion, metastasis and recurrence can also be inhibited by blocking multiple cell signaling pathways, targeting specific receptors/epigenetic targets, disrupting bioenergetics and generating reactive oxygen species (ROS).

Exploring the role of PI3K/AKT/mTOR inhibitors in hormone-related cancers: A focus on breast and prostate cancer

Breast cancer (BC) and prostate cancer (PC) are at the top of the list when it comes to the most common types of cancers worldwide. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is important, in that it strongly influences the development and progression of these tumors. Previous studies have emphasized the key role of inhibitors of the PIK3/AKT/mTOR signaling pathway in the treatment of BC and PC, and it remains to be a crucial method of treatment. In this review, the inhibitors of these signaling pathways are compared, as well as their effectiveness in therapy and potential as therapeutic agents. The use of these inhibitors as polytherapy is evaluated, especially with the use of hormonal therapy, which has shown promising results.

Oxidative stress regulation and related metabolic pathways in epithelial-mesenchymal transition of breast cancer stem cells

Epithelial-mesenchymal transition (EMT) is a cell remodeling process in which epithelial cells undergo a reversible phenotype switch via the loss of adhesion capacity and acquisition of mesenchymal characteristics. In other words, EMT activation can increase invasiveness and metastatic properties, and prevent the sensitivity of tumor cells to chemotherapeutics, as mesenchymal cells have a higher resistance to chemotherapy and immunotherapy. EMT is orchestrated by a complex and multifactorial network, often linked to episodic, transient, or partial events. A variety of factors have been implicated in EMT development. Based on this concept, multiple metabolic pathways and master transcription factors, such as Snail, Twist, and ZEB, can drive the EMT. Emerging evidence suggests that oxidative stress plays a significant role in EMT induction. One emerging theory is that reducing mitochondrial-derived reactive oxygen species production may contribute to EMT development. This review describes how metabolic pathways and transcription factors are linked to EMT induction and addresses the involvement of signaling pathways.

Recent advances in the development of inhibitors targeting KRAS-G12C and its related pathways

The RAS gene, also known as the mouse sarcoma virus, includes three genes (KRAS, HRAS, and NRAS) that are associated with human tumors. Among them, KRAS has the highest incidence of mutations in cancer, accounting for around 80% of cases. At the molecular level, the RAS gene plays a regulatory role in transcription and translation, while at the cellular level, it affects cell proliferation and migration, making it crucial for cancer development. In 2021, the FDA approved AMG510, the first direct inhibitor targeting the KRAS-G12C mutation, which has shown tumor regression, prolonged survival, and low off-target activity. However, with the increase of drug resistance, a single inhibitor is no longer sufficient to achieve the desired effect on tumors. Therefore, a large number of other highly efficient inhibitors are being developed at different stages. This article provides an overview of the mechanism of action targeting KRAS-G12C in the KRASGTP-KRASGDP cycle pathway, as well as the structure-activity relationship, structure optimization, and biological activity effects of inhibitors that target the upstream and downstream pathways, or combination therapy.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Identification of phytochemical as a dual inhibitor of PI3K and mTOR: a structure-based computational approach

Breast cancer is a common form of cancer that affects both men and women. One of the most common types of genomic flaws in cancer is the aberrations in the PI3K/AKT/mTOR pathway. The benefit of dual targeting PI3K as well as mTOR is that the kinase-positive feedback loops are more effectively inhibited. Therefore, in the current study, structure-based models like molecular docking, MM-GBSA, Qikprop, induced fit docking, simulated molecular dynamics (MD), and thermal MM-GBSA were used to identify the phytochemicals from the zinc 15 database, which may inhibit PI3K and mTOR. After docking the phytochemicals with PI3K (PDB 4FA6), ten ligands based on the docking score were selected, among which salvianolic acid C had the highest docking score. Hence, salvianolic acid A was also docked. All the ligands taken showed a binding energy of greater than - 30 kcal/mol. The predicted ADME showed that the ligands have druggable properties. By performing MD of the top five ligands and salvianolic acid A, it was found that ZINC000059728582, ZINC000257545754, ZINC000253532301, and salvianolic acid A form a stable complex with PI3K protein, among which ZINC000014690026 showed interaction with Val 882 for more than 89% of the time. Salvianolic acid A is already proven to suppress tumor growth in acute myeloid leukemia by inhibiting PI3K/AKT pathway, but the exact protein target is unknown. Therefore, the present study identifies new molecules and provides evidence for salvianolic acid A for dual inhibition. Further experiments must be performed both in vitro and in vivo to support the predictions of these computational tools.

Rumex vesicarius L. boosts the effectiveness of sorafenib in triple-negative breast cancer by downregulating BCl2, mTOR, and JNK, and upregulating p21 expression

BACKGROUND/AIM

Triple-negative breast cancer (TNBC) is characterized by poor prognosis, rapid progression, serious clinical behavior, an elevated risk of metastasis, and resistance to standard treatments. Traditional medicine practitioners value Rumex vesicarius L. (RMV) for a variety of reasons, including the plant's antioxidant capabilities. Our study's goals were to ascertain the efficacy of RMV alone and in combination with sorafenib (SOR) against the aggressive TNBC cell line (MDA-MB-231) and use in vitro and in silico analysis to deduce the fundamental mechanism of action.

METHODS

In the current study, molecular operating environment (MOE, 2019.0102) software was used for performing molecular docking. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to determine the cytotoxicity of RMV, SOR or RMV/SOR combination against the TNBC cell line MDA-MB-231 cells. The effects of RMV, SOR, and RMV and SOR combining on mRNAs expressions of the target genes including mTOR, p21, JNK, and BCl2 were evaluated. In TNBC cells, the relative expressions of mRNAs of the genes were examined by using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

In our experiments, we discovered that both RMV extracts alone and in combination with SOR considerably reduced cancer cell proliferation (IC50 = 0.83 and 0.19 μM, respectively). Additionally, the expression of the tumor suppressor gene p21 was elevated whereas the expression of the invasion and anti-apoptosis genes BCl2, mTOR, and JNK were significantly decreased after treatment with RMV and SOR. Based on in silico analysis, it was found that RMV extract contains bioactive chemicals with a high affinity for inhibiting JNK and VEGFR-2.

CONCLUSION

In conclusion, in vitro and in silico investigations show that the RMV extract improves the anticancer efficiency of SOR through molecular processes involving the downregulation of mTOR, BCl2, and JNK1 and overexpression of p21 tumor suppressor gene. Finally, we suggest conducting additional in vivo investigations on RMV and its bioactive components to verify their potential in cancer therapy.

Robust Identification of Differential Gene Expression Patterns from Multiple Transcriptomics Datasets for Early Diagnosis, Prognosis, and Therapies for Breast Cancer

Background and Objectives: Breast cancer (BC) is one of the major causes of cancer-related death in women globally. Proper identification of BC-causing hub genes (HubGs) for prognosis, diagnosis, and therapies at an earlier stage may reduce such death rates. However, most of the previous studies detected HubGs through non-robust statistical approaches that are sensitive to outlying observations. Therefore, the main objectives of this study were to explore BC-causing potential HubGs from robustness viewpoints, highlighting their early prognostic, diagnostic, and therapeutic performance. Materials and Methods: Integrated robust statistics and bioinformatics methods and databases were used to obtain the required results. Results: We robustly identified 46 common differentially expressed genes (cDEGs) between BC and control samples from three microarrays (GSE26910, GSE42568, and GSE65194) and one scRNA-seq (GSE235168) dataset. Then, we identified eight cDEGs (COL11A1, COL10A1, CD36, ACACB, CD24, PLK1, UBE2C, and PDK4) as the BC-causing HubGs by the protein-protein interaction (PPI) network analysis of cDEGs. The performance of BC and survival probability prediction models with the expressions of HubGs from two independent datasets (GSE45827 and GSE54002) and the TCGA (The Cancer Genome Atlas) database showed that our proposed HubGs might be considered as diagnostic and prognostic biomarkers, where two genes, COL11A1 and CD24, exhibit better performance. The expression analysis of HubGs by Box plots with the TCGA database in different stages of BC progression indicated their early diagnosis and prognosis ability. The HubGs set enrichment analysis with GO (Gene ontology) terms and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways disclosed some BC-causing biological processes, molecular functions, and pathways. Finally, we suggested the top-ranked six drug molecules (Suramin, Rifaximin, Telmisartan, Tukysa Tucatinib, Lynparza Olaparib, and TG.02) for the treatment of BC by molecular docking analysis with the proposed HubGs-mediated receptors. Molecular docking analysis results also showed that these drug molecules may inhibit cancer-related post-translational modification (PTM) sites (Succinylation, phosphorylation, and ubiquitination) of hub proteins. Conclusions: This study's findings might be valuable resources for diagnosis, prognosis, and therapies at an earlier stage of BC.

Is Insulin Receptor Substrate4 (IRS4) a Platform Involved in the Activation of Several Oncogenes?

The IRS (insulin receptor substrate) family of scaffold proteins includes insulin receptor substrate-4 (IRS4), which is expressed only in a few cell lines, including human kidney, brain, liver, and thymus and some cell lines. Its N-terminus carries a phosphotyrosine-binding (PTB) domain and a pleckstrin homology domain (PH), which distinguishes it as a member of this family. In this paper, we collected data about the molecular mechanisms that explain the relevance of IRS4 in the development of cancer and identify IRS4 differences that distinguish it from IRS1 and IRS2. Search engines and different databases, such as PubMed, UniProt, ENSEMBL and SCANSITE 4.0, were used. We used the name of the protein that it encodes "(IRS-4 or IRS4)", or the combination of these terms with the word "(cancer)" or "(human)", for searches. Terms related to specific tumor pathologies ("breast", "ovary", "colon", "lung", "lymphoma", etc.) were also used. Despite the lack of knowledge on IRS4, it has been reported that some cancers and benign tumors are characterized by high levels of IRS-4 expression. Specifically, the role of IRS-4 in different types of digestive tract neoplasms, gynecological tumors, lung cancers, melanomas, hematological tumors, and other less common types of cancers has been shown. IRS4 differs from IRS1 and IRS2 in that can activate several oncogenes that regulate the PI3K/Akt cascade, such as BRK and FER, which are characterized by tyrosine kinase-like activity without regulation via extracellular ligands. In addition, IRS4 can activate the CRKL oncogene, which is an adapter protein that regulates the MAP kinase cascade. Knowledge of the role played by IRS4 in cancers at the molecular level, specifically as a platform for oncogenes, may enable the identification and validation of new therapeutic targets.

The impact of particulate matters on apoptosis in various organs: Mechanistic and therapeutic perspectives

Ecological air contamination is the non-homogenous suspension of insoluble particles into gas or/and liquid fluids known as particulate matter (PM). It has been discovered that exposure to PM can cause serious cellular defects, followed by tissue damage known as cellular stress. Apoptosis is a homeostatic and regulated phenomenon associated with distinguished physiological actions inclusive of organ and tissue generation, aging, and development. Moreover, it has been proposed that the deregulation of apoptotic performs an active role in the occurrence of many disorders, such as autoimmune disease, neurodegenerative, and malignant, in the human population. Recent studies have shown that PMs mainly modulate multiple signaling pathways involved in apoptosis, including MAPK, PI3K/Akt, JAK/STAT, NFκB, Endoplasmic Stress, and ATM/P53, leading to apoptosis dysregulation and apoptosis-related pathological conditions. Here, the recently published data concerning the effect of PM on the apoptosis of various organs, with a particular focus on the importance of apoptosis as a component in PM-induced toxicity and human disease development, is carefully discussed. Moreover, the review also highlighted the various therapeutic approaches, including small molecules, miRNA replacement therapy, vitamins, and PDRN, for treating diseases caused by PM toxicity. Notably, researchers have considered medicinal herbs a potential treatment for PM-induced toxicity due to their fewer side effects. So, in the final section, we analyzed the performance of some natural products for inhibition and intervention of apoptosis arising from PM-induced toxicity.

Astragaloside IV antagonizes the malignant progression of breast cancer induced by macrophage M2 polarization through the TGF-β-regulated Akt/Foxo1 pathway

BACKGROUND

Astragaloside IV (AS‑IV) was used for breast cancer (BC) treatment in China from ancient times; however, the mechanism of the prevention effect of AS-IV on BC remains not entirely clear.

METHODS

qRT-PCR, western blot and flow cytometry were employed to validate the expression of gene and protein expressions. CCK-8 assay, scratch assay, and transwell assay were used to assess the BC cell proliferation, migration, and invasion. Co-culture of conditional medium from macrophages and BC were performed.

RESULTS

AS-IV suppressed macrophage polarized to M2 phenotype and thereby inhibited M2 macrophage-induced BC progression. The inhibitory effect of AS-IV on M2 macrophage polarization was exerted via the deactivation of the Akt/Foxo1 signaling pathway in macrophages by suppressing TGF-β. The addition of TGF-β or the treatment with Akt activator SC79 reversed the regulatory effect of AS-IV on M2 macrophage polarization, which increased M2 macrophage polarization-induced BC cell proliferation, migration and invasion.

CONCLUSION

This present study revealed a new mechanism of AS-IV inhibited M2 macrophage polarization-induced BC progression and may provide a potential target for the treatment of BC.

Interaction of phenotypic sublines isolated from triple-negative breast cancer cell line MDA-MB-231 modulates their sensitivity to paclitaxel and doxorubicin in 2D and 3D assays

Breast cancer is a rapidly evolving, multifactorial disease that accumulates numerous genetic and epigenetic alterations. These result in molecular and phenotypic heterogeneity within the tumor, the complexity of which is further amplified through specific interactions between cancer cells. We aimed to analyze cell phenotypic sublines and the influence of their interaction on drug resistance, spheroid formation, and migration. Seven sublines were derived from the MDA-MB-231 breast cancer cell line using a multiple-cell suspension dilution. The growth rate, CD133 receptor expression, migration ability, and chemosensitivity of these sublines to anticancer drugs doxorubicin (DOX) and paclitaxel (PTX) were determined. Three sublines (F5, D8, H2) have been chosen to study their interaction in 2D and 3D assays. In the 2D model, the resistance of all sublines composition to DOX decreased, but in the 3D model, the resistance of all sublines except H2, increased to both PTX and DOX. In the 3D model, the combined sublines F5 and D8 had higher resistance to DOX and statistically significantly lower resistance for PTX compared to the control. The interaction between cancer stem-like cells (F5) and increased migration cells (D8) increased resistance to PTX in cell monolayer and increased resistance against both DOX and PTX in the spheroids. The interaction of DOX-resistant (H2) cells with other cell subpopulations (D8, F5, HF) decreased the resistance to DOX in cell monolayer and both DOX and PTX in spheroids.

Abrogating Metastatic Properties of Triple-Negative Breast Cancer Cells by EGFR and PI3K Dual Inhibitors

Triple-negative breast cancer (TNBC) is a devastating BC subtype. Its aggressiveness, allied to the lack of well-defined molecular targets, usually culminates in the appearance of metastases that account for poor prognosis, particularly when they develop in the brain. Nevertheless, TNBC has been associated with epidermal growth factor receptor (EGFR) overexpression, leading to downstream phosphoinositide 3-kinase (PI3K) signaling activation. We aimed to unravel novel drug candidates for TNBC treatment based on EGFR and/or PI3K inhibition. Using a highly metastatic TNBC cell line with brain tropism (MDA-MB-231 Br4) and a library of 27 drug candidates in silico predicted to inhibit EGFR, PI3K, or EGFR plus PI3K, and to cross the blood-brain barrier, we evaluated the effects on cell viability. The half maximal inhibitory concentration (IC50) of the most cytotoxic ones was established, and cell cycle and death, as well as migration and EGFR pathway intervenient, were further evaluated. Two dual inhibitors emerged as the most promising drugs, with the ability to modulate cell cycle, death, migration and proliferation, morphology, and PI3K/AKT cascade players such as myocyte enhancer factor 2C (MEF2C) and forkhead box P1 (FOXP1). This work revealed EGFR/PI3K dual inhibitors as strong candidates to tackle brain metastatic TNBC cells.

Extensive review on breast cancer its etiology, progression, prognostic markers, and treatment

As the most frequent and vulnerable malignancy among women, breast cancer universally manifests a formidable healthcare challenge. From a biological and molecular perspective, it is a heterogenous disease and is stratified based on the etiological factors driving breast carcinogenesis. Notably, genetic predispositions and epigenetic impacts often constitute the heterogeneity of this disease. Typically, breast cancer is classified intrinsically into histological subtypes in clinical landscapes. These stratifications empower physicians to tailor precise treatments among the spectrum of breast cancer therapeutics. In this pursuit, numerous prognostic algorithms are extensively characterized, drastically changing how breast cancer is portrayed. Therefore, it is a basic requisite to comprehend the multidisciplinary rationales of breast cancer to assist the evolution of novel therapeutic strategies. This review aims at highlighting the molecular and genetic grounds of cancer additionally with therapeutic and phytotherapeutic context. Substantially, it also renders researchers with an insight into the breast cancer cell lines as a model paradigm for breast cancer research interventions.

Nanoparticle-Based Antioxidants in Stress Signaling and Programmed Cell Death in Breast Cancer Treatment

Breast cancer (BC) is a complex and heterogeneous disease, and oxidative stress is a hallmark of BC. Oxidative stress is characterized by an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms. ROS has been implicated in BC development and progression by inducing DNA damage, inflammation, and angiogenesis. Antioxidants have been shown to scavenge ROS and protect cells from oxidative damage, thereby regulating signaling pathways involved in cell growth, survival, and death. Plants contain antioxidants like ascorbic acid, tocopherols, carotenoids, and flavonoids, which have been found to regulate stress signaling and PCD in BC. Combining different antioxidants has shown promise in enhancing the effectiveness of BC treatment. Antioxidant nanoparticles, when loaded with antioxidants, can effectively target breast cancer cells and enhance their cellular uptake. Notably, these nanoparticles have shown promising results in inducing PCD and sensitizing breast cancer cells to chemotherapy, even in cases where resistance is observed. This review aims to explore how nanotechnology can modulate stress signaling and PCD in breast cancer. By summarizing current research, it underscores the potential of nanotechnology in enhancing antioxidant properties for the treatment of breast cancer.

Advancements in clinical aspects of targeted therapy and immunotherapy in breast cancer

Breast cancer is the second leading cause of death for women worldwide. The heterogeneity of this disease presents a big challenge in its therapeutic management. However, recent advances in molecular biology and immunology enable to develop highly targeted therapies for many forms of breast cancer. The primary objective of targeted therapy is to inhibit a specific target/molecule that supports tumor progression. Ak strain transforming, cyclin-dependent kinases, poly (ADP-ribose) polymerase, and different growth factors have emerged as potential therapeutic targets for specific breast cancer subtypes. Many targeted drugs are currently undergoing clinical trials, and some have already received the FDA approval as monotherapy or in combination with other drugs for the treatment of different forms of breast cancer. However, the targeted drugs have yet to achieve therapeutic promise against triple-negative breast cancer (TNBC). In this aspect, immune therapy has come up as a promising therapeutic approach specifically for TNBC patients. Different immunotherapeutic modalities including immune-checkpoint blockade, vaccination, and adoptive cell transfer have been extensively studied in the clinical setting of breast cancer, especially in TNBC patients. The FDA has already approved some immune-checkpoint blockers in combination with chemotherapeutic drugs to treat TNBC and several trials are ongoing. This review provides an overview of clinical developments and recent advancements in targeted therapies and immunotherapies for breast cancer treatment. The successes, challenges, and prospects were critically discussed to portray their profound prospects.

The effect of the alpha-specific PI3K inhibitor alpelisib combined with anti-HER2 therapy in HER2+/PIK3CA mutant breast cancer

Background

HER2 is amplified or overexpressed in around 20% of breast cancers (BC). HER2-targeted therapies have significantly improved the prognosis of patients with HER2+ BC, however, de novo and acquired resistance to anti-HER2 treatment is common. Activating mutations in the PIK3CA gene are reported in ∼30% of HER2+ BC and are associated with resistance to anti-HER2 therapies and a poor prognosis. Here, we investigated the in vitro and in vivo antitumor efficacy of the alpha-specific PI3K inhibitor alpelisib alone or in combination with anti-HER2 therapy using a panel of HER2+ BC cell lines. We also generated models of acquired resistance to alpelisib to investigate the mechanisms underlying resistance to alpha-specific PI3K inhibition.

Materials and methods

PIK3CA mutant (HCC1954, KPL4 and JMT1) and wild-type (BT474 and SKBR3) HER2+ BC cell lines were used. The HCC1954 and KPL4 cells were chronically exposed to increasing concentrations of alpelisib or to alpelisib + trastuzumab in order to generate derivatives with acquired resistance to alpelisib (AR) and to alpelisib + trastuzumab (ATR). The transcriptomic profiles of HCC1954, KPL4 and their AR and ATR derivatives were determined by RNA sequencing. Cell growth was assessed by MTT assay. Changes in the protein levels of key PI3K pathway components were assessed by Western blotting. Gene expression, cellular and patients' data from the Cancer Dependency Map (DepMap) and KMPlot datasets were interrogated.

Results

HER2+ BC cell lines harboring activating mutations in PIK3CA were less sensitive to single or dual anti-HER2 blockade compared to PIK3CA wild-type cells. Alpelisib treatment resulted in dose-dependent inhibition of the growth of cells with or without PIK3CA mutations and enhanced the antitumor efficacy of anti-HER2 therapies in vitro. In addition, alpelisib greatly delayed tumor growth of HCC1954 xenografts in vivo. Functional annotation of the significantly differentially expressed genes suggested the common activation of biological processes associated with oxidation reduction, cell proliferation, immune response and RNA synthesis in alpelisib-resistant models compared with native cells. Eight commonly upregulated genes (log2 fold-change >1, False Discovery Rate [FDR] <0.05) in models with acquired resistance to alpelisib or alpelisib + trastuzumab were identified. Among these, AKR1C1 was associated with alpelisib-resistance in vitro and with a poor prognosis in patients with HER2+ BC.

Conclusions

Our findings support the use of an alpha-selective PI3K inhibitor to overcome the therapeutic limitations associated with single or dual HER2 blockade in PIK3CA-mutant HER2+ breast cancer. Future studies are warranted to confirm the potential role of candidate genes/pathways in resistance to alpelisib.

FGF1 Protects MCF-7 Cells against Taltobulin through Both the MEKs/ERKs and PI3K/AKT Signaling Pathway

Breast cancer is a widespread and complex disease characterized by abnormal signaling pathways that promote tumor growth and progression. Despite significant medical advances and the development of increasingly effective therapies for breast cancer, drug resistance and reduced sensitivity to prior therapies remain persistent challenges. Dysregulation of growth factors such as FGFs and EGF and their receptors is a contributing factor to reduced response to treatment, promoting cell survival and proliferation, metastasis, EMT or increased expression of ABC transporters. Our study demonstrates a protective role for FGF1 in MCF-7 breast cancer cells against taltobulin-induced cytotoxicity, mediated by activation of its receptors and compares its activity to EGF, another growth factor involved in breast cancer development and progression. The mechanisms of action of these two proteins are different: FGF1 exerts its effects through the activation of both ERKs and AKT, whereas EGF acts only through ERKs. FGF1 action in the presence of the drug promotes cell viability, reduces apoptosis and increases cell migration. Although EGF and its receptors have received more attention in breast cancer research to date, our findings highlight the key role played by FGFs and their receptors in promoting drug resistance to tubulin polymerization inhibitors in FGFR-positive tumors.

Uncharacterized Proteins CxORFx: Subinteractome Analysis and Prognostic Significance in Cancers

Functions of about 10% of all the proteins and their associations with diseases are poorly annotated or not annotated at all. Among these proteins, there is a group of uncharacterized chromosome-specific open-reading frame genes (CxORFx) from the 'Tdark' category. The aim of the work was to reveal associations of CxORFx gene expression and ORF proteins' subinteractomes with cancer-driven cellular processes and molecular pathways. We performed systems biology and bioinformatic analysis of 219 differentially expressed CxORFx genes in cancers, an estimation of prognostic significance of novel transcriptomic signatures and analysis of subinteractome composition using several web servers (GEPIA2, KMplotter, ROC-plotter, TIMER, cBioPortal, DepMap, EnrichR, PepPSy, cProSite, WebGestalt, CancerGeneNet, PathwAX II and FunCoup). The subinteractome of each ORF protein was revealed using ten different data sources on physical protein-protein interactions (PPIs) to obtain representative datasets for the exploration of possible cellular functions of ORF proteins through a spectrum of neighboring annotated protein partners. A total of 42 out of 219 presumably cancer-associated ORF proteins and 30 cancer-dependent binary PPIs were found. Additionally, a bibliometric analysis of 204 publications allowed us to retrieve biomedical terms related to ORF genes. In spite of recent progress in functional studies of ORF genes, the current investigations aim at finding out the prognostic value of CxORFx expression patterns in cancers. The results obtained expand the understanding of the possible functions of the poorly annotated CxORFx in the cancer context.

The current advances of lncRNAs in breast cancer immunobiology research

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-related death in women worldwide. Breast cancer development and progression are mainly associated with tumor-intrinsic alterations in diverse genes and signaling pathways and with tumor-extrinsic dysregulations linked to the tumor immune microenvironment. Significantly, abnormal expression of lncRNAs affects the tumor immune microenvironment characteristics and modulates the behavior of different cancer types, including breast cancer. In this review, we provide the current advances about the role of lncRNAs as tumor-intrinsic and tumor-extrinsic modulators of the antitumoral immune response and the immune microenvironment in breast cancer, as well as lncRNAs which are potential biomarkers of tumor immune microenvironment and clinicopathological characteristics in patients, suggesting that lncRNAs are potential targets for immunotherapy in breast cancer.

Spatial Proteomics for the Molecular Characterization of Breast Cancer

Breast cancer (BC) is a major global health issue, affecting a significant proportion of the female population and contributing to high rates of mortality. One of the primary challenges in the treatment of BC is the disease's heterogeneity, which can lead to ineffective therapies and poor patient outcomes. Spatial proteomics, which involves the study of protein localization within cells, offers a promising approach for understanding the biological processes that contribute to cellular heterogeneity within BC tissue. To fully leverage the potential of spatial proteomics, it is critical to identify early diagnostic biomarkers and therapeutic targets, and to understand protein expression levels and modifications. The subcellular localization of proteins is a key factor in their physiological function, making the study of subcellular localization a major challenge in cell biology. Achieving high resolution at the cellular and subcellular level is essential for obtaining an accurate spatial distribution of proteins, which in turn can enable the application of proteomics in clinical research. In this review, we present a comparison of current methods of spatial proteomics in BC, including untargeted and targeted strategies. Untargeted strategies enable the detection and analysis of proteins and peptides without a predetermined molecular focus, whereas targeted strategies allow the investigation of a predefined set of proteins or peptides of interest, overcoming the limitations associated with the stochastic nature of untargeted proteomics. By directly comparing these methods, we aim to provide insights into their strengths and limitations and their potential applications in BC research.

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.

The CDK4/6 Inhibitor Palbociclib Inhibits Estrogen-Positive and Triple Negative Breast Cancer Bone Metastasis In Vivo

CDK 4/6 inhibitors have demonstrated significant improved survival for patients with estrogen receptor (ER) positive breast cancer (BC). However, the ability of these promising agents to inhibit bone metastasis from either ER+ve or triple negative BC (TNBC) remains to be established. We therefore investigated the effects of the CDK 4/6 inhibitor, palbociclib, using in vivo models of breast cancer bone metastasis. In an ER+ve T47D model of spontaneous breast cancer metastasis from the mammary fat pad to bone, primary tumour growth and the number of hind limb skeletal tumours were significantly lower in palbociclib treated animals compared to vehicle controls. In the TNBC MDA-MB-231 model of metastatic outgrowth in bone (intracardiac route), continuous palbociclib treatment significantly inhibited tumour growth in bone compared to vehicle. When a 7-day break was introduced after 28 days (mimicking the clinical schedule), tumour growth resumed and was not inhibited by a second cycle of palbociclib, either alone or when combined with the bone-targeted agent, zoledronic acid (Zol), or a CDK7 inhibitor. Downstream phosphoprotein analysis of the MAPK pathway identified a number of phosphoproteins, such as p38, that may contribute to drug-insensitive tumour growth. These data encourage further investigation of targeting alternative pathways in CDK 4/6-insensitive tumour growth.

Triazole-fused pyrimidines in target-based anticancer drug discovery

In recent decades, the development of targeted drugs has featured prominently in the treatment of cancer, which is among the major causes of mortality globally. Triazole-fused pyrimidines, a widely-used class of heterocycles in medicinal chemistry, have attracted considerable interest as potential anticancer agents that target various cancer-associated targets in recent years, demonstrating them as valuable templates for discovering novel anticancer candidates. The current review concentrates on the latest advancements of triazole-pyrimidines as target-based anticancer agents, including works published between 2007 and the present (2007-2022). The structure-activity relationships (SARs) and multiple pathways are also reviewed to shed light on the development of more effective and biotargeted anticancer candidates.

High expression of IGHG1 promotes breast cancer malignant development by activating the AKT pathway

This study researched the exact function of IgG1 heavy chain (IGHG1) on breast cancer (BC) progression. IGHG1 level within BC and paired normal tissues was acquired in Gene Expression Profiling Interactive Analysis dataset. Meanwhile, this work harvested tumor and paired healthy tissues in 42 BC cases. siRNA targeting IGHG1 was transfected into BC cells. SC79 was used to treat the transfected BC cells. CCK-8 assay, clone formation experiment, BrdU assay, Transwell experiment and flow cytometry were carried out to measure the viability, colony formation, proliferation, invasion, and apoptosis of BC cells. Paclitaxel and cisplatin sensitivity of BC cells was evaluated by MTT assay. Real-time quantitative reverse transcription-polymerase chain reaction and Western-blot were performed for measuring mRNA and protein expression. The overexpressed IGHG1 indicated dismal BC survival. IGHG1 silencing attenuated the viability, invasion, proliferation, epithelial-mesenchymal transition, but enhanced the apoptosis of BC cells. IGHG1 silencing enhanced the paclitaxel and cisplatin sensitivity of BC cells. IGHG1 silencing suppressed the activity of the MEK, AKT, and ERK pathways. AKT agonist partially reversed the inhibition of IGHG1 silencing on BC cell malignant phenotype and resistance to paclitaxel and cisplatin. IGHG1 promotes the malignant development of BC by activating the AKT pathway. It may be an effective target for BC treatment.

Design, synthesis and molecular docking of novel substituted azepines as inhibitors of PI3K/Akt/TSC2/mTOR signaling pathway in colorectal carcinoma

A series of novel substituted azepines (2-7) was synthesized using both traditional and ultrasonic techniques. The efficiency of the reaction rate and yield was improved by sonication technique. We identified the newly synthesized compounds based on their melting points, elemental analyses, and spectral data. Human cancers are regulated mainly by the phosphatidylinositol 3-kinase/protein kinases B (PI3K/Akt) pathway, and its abnormal activation is linked to carcinogenesis, and angiogenesis. Using in-silico studies, we evaluated the ability of all the novel substituted diazepines and oxazepines to prevent cancer growth and metastasis by targeting the PI3K/Akt signaling pathway. Based on our findings, compounds 4a and 7a were chosen for in-vitro testing as they ranked via molecular docking the highest binding energies of -10.9, -10.3, -10.6, and -10.4 kcal/mol respectively. Compounds 4a and 7a displayed significant cytotoxicity on Caco-2 colorectal cancer cells with IC₅₀ values of 8.445 ± 2.26 and 33.04 ± 2.06 μM, respectively. Additionally, they considerably suppressed the PI3K/Akt proteins and generated reactive oxygen species (ROS), which increased p53 and Bax, decreased Bcl-₂ levels, and arrested the cell cycle at sub-G0/G1 phase. We also observed a remarkable overexpression of the Tuberous Sclerosis Complex 2 (TSC2) gene, an inhibitor of the mammalian target of rapamycin (mTOR). These results showed that compounds 4a and 7a obeyed Lipinski's rule of five and might be potential cancer treatment scaffolds by preventing metastasis and proliferation via blocking the PI3K/Akt/TSC2/m-TOR signaling pathway. This supports our hypothesis that diazepine 4a and oxazepine 7a are promising drug candidates for colorectal cancer.

LACTB induces cancer cell death through the activation of the intrinsic caspase-independent pathway in breast cancer

BACKGROUND

LACTB was recently identified as a mitochondrial tumour suppressor that negatively affects cancer cell proliferation by inducing cell death and/or differentiation, depending on the cell type and tissue. However, the detailed mechanism underlying the LACTB-induced cancer cell death is largely unknown.

METHODS

We used cell-based, either in 2D or 3D conditions, and in vivo experiments to understand the LACTB mechanisms. In this regard, protein array followed by an enrichment analysis, cell proliferation assays using different compounds, western blot analysis, flow cytometry and immunofluorescence were performed. Differences between quantitative variables following normal distribution were valuated using Student t test for paired or no-paired samples according to the experiment. For in vivo experiments differences in tumour growth were analyzed by 2-way ANOVA.

RESULTS

We show, that LACTB expression leads to cell cycle arrest in G1 phase and increase of DNA oxidation that leads to activation of intrinsic caspase-independent cell death pathway. This is achieved by an increase of mitochondrial reactive oxygen species since early time points of LACTB induction.

CONCLUSION

Our work provides a deeper mechanistic insight into LACTB-mediated cancer-cell death and shows the dynamics of the cellular responses a particular tumor suppressive stimulus might evoke under different genetic landscapes.

Genetic architecture of mammographic density as a risk factor for breast cancer: a systematic review

BACKGROUND

Mammography Density (MD) is a potential risk marker that is influenced by genetic polymorphisms and can subsequently modulate the risk of breast cancer. This qualitative systematic review summarizes the genes and biological pathways involved in breast density and discusses the potential clinical implications in view of the genetic risk profile for breast density.

METHODS

The terms related to "Common genetic variations" and "Breast density" were searched in Scopus, PubMed, and Web of Science databases. Gene pathways analysis and assessment of protein interactions were also performed.

RESULTS

Eighty-six studies including 111 genes, reported a significant association between mammographic density in different populations. ESR1, IGF1, IGFBP3, and ZNF365 were the most prevalent genes. Moreover, estrogen metabolism, signal transduction, and prolactin signaling pathways were significantly related to the associated genes. Mammography density was an associated phenotype, and eight out of 111 genes, including COMT, CYP19A1, CYP1B1, ESR1, IGF1, IGFBP1, IGFBP3, and LSP1, were modifiers of this trait.

CONCLUSION

Genes involved in developmental processes and the evolution of secondary sexual traits play an important role in determining mammographic density. Due to the effect of breast tissue density on the risk of breast cancer, these genes may also be associated with breast cancer risk.

Kalkitoxin: A Potent Suppressor of Distant Breast Cancer Metastasis

Bone metastasis resulting from advanced breast cancer causes osteolysis and increases mortality in patients. Kalkitoxin (KT), a lipopeptide toxin derived from the marine cyanobacterium Moorena producens (previously Lyngbya majuscula), has an anti-metastatic effect on cancer cells. We verified that KT suppressed cancer cell migration and invasion in vitro and in animal models in the present study. We confirmed that KT suppressed osteoclast-soup-derived MDA-MB-231 cell invasion in vitro and induced osteolysis in a mouse model, possibly enhancing/inhibiting metastasis markers. Furthermore, KT inhibits CXCL5 and CXCR2 expression, suppressing the secondary growth of breast cancer cells on the bone, brain, and lungs. The breast-cancer-induced osteolysis in the mouse model further reveals that KT plays a protective role, judging by micro-computed tomography and immunohistochemistry. We report for the first time the novel suppressive effects of KT on cancer cell migration and invasion in vitro and on MDA-MB-231-induced bone loss in vivo. These results suggest that KT may be a potential therapeutic drug for the treatment of breast cancer metastasis.

PI3K-AKT-Targeting Breast Cancer Treatments: Natural Products and Synthetic Compounds

Breast cancer is the most commonly diagnosed cancer in women. The high incidence of breast cancer, which is continuing to rise, makes treatment a significant challenge. The PI3K-AKT pathway and its downstream targets influence various cellular processes. In recent years, mounting evidence has shown that natural products and synthetic drugs targeting PI3K-AKT signaling have the potential to treat breast cancer. In this review, we discuss the role of the PI3K-AKT signaling pathway in the occurrence and development of breast cancer and highlight PI3K-AKT-targeting natural products and drugs in clinical trials for the treatment of breast cancer.