Molecularly Targeted Therapies for Triple Negative Breast Cancer: History, Advances, and Future Directions

Exploring chromone-2-carboxamide derivatives for triple-negative breast cancer targeting EGFR, FGFR3, and VEGF pathways: Design, synthesis, and preclinical insights

Chromone-based compounds have established cytotoxic, antiproliferative, antimetastatic, and antiangiogenic effects on various cancer cell types via modulating different molecular targets. Herein, 17 novel chromone-2-carboxamide derivatives were synthesized and evaluated for their in vitro anticancer activity against 15 human cancer cell lines. Among the tested cell lines, MDA-MB-231, the triple-negative breast cancer cell line, was found to be the most sensitive, where the N-(2-furylmethylene) (15) and the α-methylated N-benzyl (17) derivatives demonstrated the highest growth inhibition with GI50 values of 14.8 and 17.1 μM, respectively. In vitro mechanistic studies confirmed the significant roles of compounds 15 and 17 in the induction of apoptosis and suppression of EGFR, FGFR3, and VEGF protein levels in MDA-MB-231 cancer cells. Moreover, compound 15 exerted cell cycle arrest at both the G0-G1 and G2-M phases. The in vivo efficacy of compound 15 as an antitumor agent was further investigated in female mice bearing Solid Ehrlich Carcinoma. Notably, administration of compound 15 resulted in a marked decrease in both tumor weight and volume, accompanied by improvements in biochemical, hematological, histological, and immunohistochemical parameters that verified the repression of both angiogenesis and inflammation as additional Anticancer mechanisms. Moreover, the binding interactions of compounds 15 and 17 within the binding sites of all three target receptors (EGFR, FGFR3, and VEGF) were clearly illustrated using molecular docking.

20(R)-Panaxatriol enhances METTL3-mediated m6A modification of STUB1 to inhibit autophagy and exert antitumor effects in Triple-Negative Breast Cancer cells

BACKGROUND

Aberrant activation of autophagy in triple-negative breast cancer (TNBC) has led researchers to investigate potential therapeutic strategies targeting this process. The regulation of autophagy is significantly influenced by METTL3. Our previous research has shown that the Panax ginseng-derived compound, 20(R)-panaxatriol (PT), has potential as an anti-tumor agent. However, it remains unclear whether PT can modulate autophagy through METTL3 to exert its anti-tumor effects.

OBJECTIVE

Our objective is to investigate whether PT can regulate autophagy in TNBC cells and elucidate the molecular mechanisms.

STUDY DESIGN

For in vitro experiments, we employed SUM-159-PT and MDA-MB-231 cells. While in vivo experiments involved BALB/c nude mice and NOD/SCID mice.

METHODS

In vitro, TNBC cells were treated with PT, and cell lines with varying expression levels of METTL3 were established. We assessed the impact on tumor cell activity and autophagy by analyzing autophagic flux, Western Blot (WB), and methylation levels. In vivo, subcutaneous transplantation models were established in BALB/c nude and NOD/SCID mice to observe the effect of PT on TNBC growth. HE staining and immunofluorescence were employed to analyze histopathological changes in tumor tissues. MeRIP-seq and dual-luciferase reporter gene assays were used to identify key downstream targets. Additionally, the silencing of STIP1 Homology And U-Box Containing Protein 1 (STUB1) explored PT's effects. The mechanism of PT's action on STUB1 via METTL3 was elucidated through mRNA stability assays, mRNA alternative splicing analysis, and nuclear-cytoplasmic mRNA separation.

RESULTS

In both in vivo and in vitro experiments, it was discovered that PT significantly upregulates the expression of METTL3, leading to autophagy inhibition and therapeutic effects in TNBC. Simultaneously, through MeRIP-seq analysis and dual-luciferase reporter gene assays, we have demonstrated that PT modulates STUB1 via METTL3, influencing autophagy in TNBC cells. Furthermore, intriguingly, PT extends the half-life of STUB1 mRNA by enhancing its methylation modification, thereby enhancing its stability.

CONCLUSION

In summary, our research reveals that PT increases STUB1 m6A modification through a METTL3-mediated mechanism in TNBC cells, inhibiting autophagy and further accentuating its anti-tumor properties. Our study provides novel mechanistic insights into TNBC pathogenesis and potential drug targets for TNBC.

A PET-Surrogate Signature for the Interrogation of the Metabolic Status of Breast Cancers

Metabolic alterations in cancers can be exploited for diagnostic, prognostic, and therapeutic purposes. This is exemplified by 18F-fluorodeoxyglucose (FDG)-positron emission tomography (FDG-PET), an imaging tool that relies on enhanced glucose uptake by tumors for diagnosis and staging. By performing transcriptomic analysis of breast cancer (BC) samples from patients stratified by FDG-PET, a 54-gene signature (PETsign) is identified that recapitulates FDG uptake. PETsign is independently prognostic of clinical outcome in luminal BCs, the most common and heterogeneous BC molecular subtype, which requires improved stratification criteria to guide therapeutic decision-making. The prognostic power of PETsign is stable across independent BC cohorts and disease stages including the earliest BC stage, arguing that PETsign is an ab initio metabolic signature. Transcriptomic and metabolomic analysis of BC cells reveals that PETsign predicts enhanced glycolytic dependence and reduced reliance on fatty acid oxidation. Moreover, coamplification of PETsign genes occurs frequently in BC arguing for their causal role in pathogenesis. CXCL8 and EGFR signaling pathways feature strongly in PETsign, and their activation in BC cells causes a shift toward a glycolytic phenotype. Thus, PETsign serves as a molecular surrogate for FDG-PET that could inform clinical management strategies for BC patients.

Comparing the HER2 Status of the Primary Tumor to That of Disseminated Tumor Cells in Early Breast Cancer

Breast cancer remains a leading cause of cancer mortality in women globally. Despite advancements in systemic therapy, the risk of distant recurrence persists even after such treatment and may be linked to disseminated tumor cells (DTCs). Variability in molecular characteristics between primary tumors (PTs) and distant metastases underscores the need to comprehensively understand metastatic pathways. This retrospective study investigated discrepancies between HER2 expression in PTs and DTCs and their implications for survival outcomes in 201 early breast cancer (EBC) patients. We found a significant association between HER2 expression in PTs and DTCs when classifying tumors as HER2-high/low/negative. Patients whose HER2 status was discordant between PTs and DTCs exhibited worse distant disease-free survival than those with concordant status. Multivariate analysis confirmed the HER2 status of DTCs as an independent prognostic factor for distant DFS. These findings emphasize the importance of assessing HER2 expression in DTCs and its potential implications for tailored therapy strategies in EBC. Furthermore, prospective trials are needed to validate these findings and explore targeted therapies based on the molecular characteristics of DTCs.

Effects of Garlic on Breast Tumor Cells with a Triple Negative Phenotype: Peculiar Subtype-Dependent Down-Modulation of Akt Signaling

Breast cancer includes tumor subgroups with morphological, molecular, and clinical differences. Intrinsic heterogeneity especially characterizes breast tumors with a triple negative phenotype, often leading to the failure of even the most advanced therapeutic strategies. To improve breast cancer treatment, the use of natural agents to integrate conventional therapies is the subject of ever-increasing attention. In this context, garlic (Allium sativum) shows anti-cancerous potential, interfering with the proliferation, motility, and malignant progression of both non-invasive and invasive breast tumor cells. As heterogeneity could be at the basis of variable effects, the main objective of our study was to evaluate the anti-tumoral activity of a garlic extract in breast cancer cells with a triple negative phenotype. Established triple negative breast cancer (TNBC) cell lines from patient-derived xenografts (PDXs) were used, revealing subtype-dependent effects on morphology, cell cycle, and invasive potential, correlated with the peculiar down-modulation of Akt signaling, a crucial regulator in solid tumors. Our results first demonstrate that the effects of garlic on TNBC breast cancer are not unique and suggest that only more precise knowledge of the mechanisms activated by this natural compound in each tumor will allow for the inclusion of garlic in personalized therapeutic approaches to breast cancer.

SORBS1 inhibits epithelial to mesenchymal transition (EMT) of breast cancer cells by regulating PI3K/AKT signaling and macrophage phenotypic polarization

This study aimed to explore the regulatory role of SORBS1 in macrophage polarization and the PI3K/AKT signaling pathway, as well as analyze its mechanism in epithelial-mesenchymal transition (EMT) of breast cancer cells. We established SORBS1-overexpressing and knockout cell lines and verified the effects of SORBS1 on cell viability, invasion, and migration by phenotyping experiments and assaying the expression of associated proteins. Furthermore, we established a breast cancer cell and macrophage co-culture system to validate the effect of SORBS1 expression on macrophage polarization and killing of breast cancer cells. Bioinformatics analysis showed that SORBS1 was lowly expressed in breast cancer (BRCA) samples and highly expressed in healthy tissues. Decreased SORBS1 expression was associated with poor prognosis, and the PI3K/AKT signaling pathway was the most significantly enriched pathway. In vitro experiments showed that high expression of SORBS1 inhibited the migration of breast cancer cells, as well as the PI3K/AKT signaling pathway, and blocked EMT of these cells. In addition, SORBS1 induced macrophage polarization to the M1-type and enhanced the killing effect on breast cancer cells in the co-culture system. In conclusion, we successfully verified that SORBS1 inhibits the invasion and migration of breast cancer cells, induces macrophage M1-type polarization, and blocks EMT of breast cancer cells, and it may act by regulating the PI3K/AKT signaling pathway.

Innovations in Precision Oncology: Biomarker-Driven Approaches for Enhanced Cancer Therapy

Precision oncology is revolutionized by targeted therapies like talazoparib, a PARP inhibitor, leveraging advanced understanding of DNA repair mechanisms such as ribonucleotide excision repair and homologous recombination repair. CRISPR-Cas technology has been pivotal in unraveling these pathways, facilitating personalized treatment strategies. The identification of genomic loss of heterozygosity as a biomarker targets HRR-deficient cancers, enhancing talazoparib's efficacy. These breakthroughs represent a significant advancement in precision medicine, offering more effective, individualized cancer therapies.

PD-L1 testing in metastatic triple negative breast cancer: Results of an Italian survey

BACKGROUND

Immunotherapy has revolutionized the approach to metastatic triple-negative breast cancers. Atezolizumab was approved for patients with metastatic triple-negative breast cancers whose tumors express PD-L1, determined by SP 142 assay. To assess the availability and practice of SP142 test we administered a survey to all the 15 pathology departments of the Lazio Region during a six-month period.

METHODS

The survey comprised 12 questions regarding the availability of SP142 in the pathology departments, the percentage of positive tests, the difficulties of pathologists in cases close to cut-off value and the tested samples.

RESULTS

The SP142 assay was available in only eight centers. In case of positive result, most centers (5/8, 62.5%) reported values of PD-L1 expression ranging from > 1 to ⩽ 5%, with values close to the cut-off point (⩾ 1% or < 1%) being the greatest challenge.Most of the centers (6/8, 75%) tested material from both their own and other hospitals. In most centers, the evaluations were performed either on primary tumors or metastasis, in particular lymph nodes (5/8, 62.5%), followed by lung (3/8, 37.5%) and liver (1/8, 12.5%) metastasis.

CONCLUSION

Our results raise some important issues concerning the evaluation of PD-L1 in the "real-life" setting, providing strategies for its implementation.

Application of Novel Transcription Factor Machine Learning Model and Targeted Drug Combination Therapy Strategy in Triple Negative Breast Cancer

Transcription factors (TFs) have been shown to play a key role in the occurrence and development of tumors, including triple-negative breast cancer (TNBC), with a worse prognosis. Machine learning is widely used for establishing prediction models and screening key tumor drivers. Current studies lack TF integration in TNBC, so targeted research on TF prognostic models and targeted drugs is beneficial to improve clinical translational application. The purpose of this study was to use the Least Absolute Shrinkage and Selection Operator to build a prognostic TFs model after cohort normalization based on housekeeping gene expression levels. Potential targeted drugs were then screened on the basis of molecular docking, and a multi-drug combination strategy was used for both in vivo and in vitro experimental studies. The machine learning model of TFs built by E2F8, FOXM1, and MYBL2 has broad applicability, with an AUC value of up to 0.877 at one year. As a high-risk clinical factor, its abnormal disorder may lead to upregulation of the activity of pathways related to cell proliferation. This model can also be used to predict the adverse effects of immunotherapy in patients with TNBC. Molecular docking was used to screen three drugs that target TFs: Trichostatin A (TSA), Doxorubicin (DOX), and Calcitriol. In vitro and in vivo experiments showed that TSA + DOX was able to effectively reduce DOX dosage, and TSA + DOX + Calcitriol may be able to effectively reduce the toxic side effects of DOX on the heart. In conclusion, the machine learning model based on three TFs provides new biomarkers for clinical and prognostic diagnosis of TNBC, and the combination targeted drug strategy offers a novel research perspective for TNBC treatment.