Blockage of αvβ3 integrin in 3D culture of triple-negative breast cancer and endothelial cells inhibits migration and discourages endothelial-to-mesenchymal plasticity

Breast cancer is a relevant cause of mortality in women and its triple-negative subtype (TNBC) is usually associated with poor prognosis. During tumor progression to metastasis, angiogenesis is triggered by the sprouting of endothelial cells from pre-existing vessels by a dynamic chain of events including VE-cadherin downregulation, actin protrusion, and integrin-mediated adhesion, allowing for migration and proliferation. The binding of tumoral and tumor-associated stromal cells with the extracellular matrix through integrins mediates angiogenic processes and certain integrin subtypes, such as the αvβ3 integrin, are upregulated in hypoxic TNBC models. Integrin αvβ3 inhibition by the high-affinity binding disintegrin DisBa-01 was previously demonstrated to induce anti-tumoral and anti-angiogenic responses in traditional 2D cell assays. Here, we investigate the effects of integrin αvβ3 blockage in endothelial and TNBC cells by DisBa-01 in 3D cultures under two oxygen conditions (1% and 20%). 3D cultures created using non-adhesive micromolds with Matrigel were submitted to migration assay in Boyden chambers and fluorescence analysis. DisBa-01 inhibited cell migration in normoxia and hypoxia in both MDA-MB-231 and HUVEC spheroids. Protein levels of integrin αvβ3 were overexpressed in HUVEC spheroids compared to MDA-MB-231 spheroids. In HUVEC 3D cultures, sprouting assays in collagen type I were decreased in normoxia upon DisBa-01 treatment, and VE-cadherin levels were diminished in HUVEC spheroids in hypoxia and upon DisBa-01 treatment. In conclusion, the blockage of integrin αvβ3 by DisBa-01 inhibits cell migration in 3D culture and interferes with tumor-derived responses in different oxygen settings, implicating its crucial role in angiogenesis and tumor progression.

Identification of biomimetic nanoplatform-mediated delivery of si-ISG15 for treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is recognized as the most malicious form of breast cancer and exhibits an alarming tendency for recurrence, a heightened propensity for metastasis, and an overwhelmingly grim prognosis. Therefore, effective therapy approaches for TNBC are urgently required. In this study, the interferon-stimulated gene 15 (ISG15) expression level was analyzed by bioinformatics and verified by Western blot analysis. The effects of ISG15 on the proliferation and metastasis of TNBC cells were assessed using MTT, Colony formation, EdU, Transwell, and Flow cytometry assays. We also developed a cancer cell-biomimetic nanoparticle delivery system and evaluated its therapeutic efficacy in vivo. In this study, we reported that ISG15 was upregulated in TNBC, and its high expression level correlated with an increased risk of tumorigenesis. Through in vitro and in vivo studies, we discovered that ISG15 knockdown drastically suppressed cell proliferation, invasion, and migration and induced apoptosis in TNBC cells. Our findings revealed that ISG15 was a candidate therapeutic target in TNBC because of its key role in malignant growth and invasion. Moreover, co-immunoprecipitation showed that ISG15 exerted oncogenic functions through its interaction with ATP binding cassette subfamily E member 1 and activated the Janus kinase/signal transducers and activators of the transcription signaling pathway. Furthermore, we created a nanoparticle-based siRNA camouflaged using a cancer cell membrane vesicle delivery system (the CM@NP complex) and confirmed its therapeutic effects in vivo. Our findings confirmed that ISG15 may play a pivotal oncogenic role in the development of TNBC and that CM@siRNA-NP complexes are an effective delivery system and a novel biological strategy for treating TNBC.

Safety and efficacy of anlotinib combined with taxane and lobaplatin in neoadjuvant treatment of clinical stage II/III triple-negative breast cancer in China (the neoALTAL trial): a single-arm, phase 2 trial

Background

Anlotinib is a new type of tyrosine kinase inhibitor that targets vascular endothelial growth factor receptors 1/2/3, platelet-derived growth factor receptors α/β, and fibroblast growth factor receptors 1-4 and c-Kit, with a broad spectrum of inhibitory effects on tumor angiogenesis and growth. It has been proven effective in HER2-negative metastatic breast cancer, but its efficacy in early-stage triple-negative breast cancer (TNBC) is unknown. This phase 2 study aims to evaluate the efficacy and safety of adding anlotinib to neoadjuvant chemotherapy in patients with TNBC.

Methods

Patients with clinical stage II/III TNBC were treated with 5 cycles of anlotinib (12 mg, d1-14, q3w) plus 6 cycles of taxanes (docetaxel 75 mg/m2 ,d1, q3w or nab-paclitaxel 125 mg/m2, d1 and d8, q3w) and lobaplatin (30 mg/m2, d1, q3w), followed by surgery. The primary endpoint was pathological complete response (pCR; ypT0/is ypN0) and the secondary endpoints include breast pCR (bpCR), axillary pCR (apCR), residual cancer burden (RCB), objective response rate (ORR), survival, and safety. Exploratory endpoints were efficacy biomarkers based on Fudan University Shanghai Cancer Center Immunohistochemical (FUSCC IHC) classification for TNBC and next-generation sequencing (NGS) of DNA from tumor tissue and blood samples of patients with 425-gene panel. This trial is registered with www.chictr.org.cn (ChiCTR2100043027).

Findings

From Jan 2021 to Aug 2022, 48 patients were assessed and 45 were enrolled. All patients received at least one dose of study treatment and underwent surgery. The median age was 48.5 years (SD: 8.7), 71% were nodal involved, and 20% had stage III. In the intention-to-treat population, 26 out of 45 patients achieved pCR (57.8%; 90% CI, 44.5%-70.3%), and 39 achieved residual cancer burden class 0-I (86.7%; 95% CI, 73.2%-94.9%). The bpCR and apCR rate were 64.4% (29/45) and 71.9% (23/32), respectively. No recurrence or metastasis occurred during the short-term follow-up. Based on the FUSCC IHC-based subtypes, the pCR rates were 68.8% (11/16) for immunomodulatory subtype, 58.3% (7/12) for basal-like immune-suppressed subtype and 33.3% (4/12) for luminal androgen receptor subtype, respectively. NGS revealed that the pCR were 77% (10/13) and 50% (14/28) in MYC-amplified and wild-type patients, respectively, and 78% (7/9) and 53% (17/32) in gBRCA1/2-mutated and wild-type patients, respectively. The median follow-up time of the study was 14.9 months (95% CI: 13.5-16.3 months). There was no disease progression or death during neoadjuvant therapy. No deaths occurred during postoperative follow-up. In the safety population (N = 45), Grade 3 or 4 treatment emergent adverse events occurred in 29 patients (64%), and the most common events were neutropenia (38%), leukopenia (27%), thrombocytopenia (25%), anemia (13%), and hypertension (13%), respectively.

Interpretation

The addition of anlotinib to neoadjuvant chemotherapy showed manageable toxicity and encouraging antitumor activity for patients with clinical stage II/III TNBC.

Funding

Chongqing Talents Project, Chongqing Key Project of Technology Innovation and Application Development and Chongqing Outstanding Youth Natural Science Foundation.

A novel approach correlating pathologic complete response with digital pathology and radiomics in triple-negative breast cancer

This rapid communication highlights the correlations between digital pathology-whole slide imaging (WSI) and radiomics-magnetic resonance imaging (MRI) features in triple-negative breast cancer (TNBC) patients. The research collected 12 patients who had both core needle biopsy and MRI performed to evaluate pathologic complete response (pCR). The results showed that higher collagenous values in pathology data were correlated with more homogeneity, whereas higher tumor expression values in pathology data correlated with less homogeneity in the appearance of tumors on MRI by size zone non-uniformity normalized (SZNN). Higher myxoid values in pathology data are correlated with less similarity of gray-level non-uniformity (GLN) in tumor regions on MRIs, while higher immune values in WSIs correlated with the more joint distribution of smaller-size zones by small area low gray-level emphasis (SALGE) in the tumor regions on MRIs. Pathologic complete response (pCR) was associated with collagen, tumor, and myxoid expression in WSI and GLN and SZNN in radiomic features. The correlations of WSI and radiomic features may further our understanding of the TNBC tumoral microenvironment (TME) and could be used in the future to better tailor the use of neoadjuvant chemotherapy (NAC). This communication will focus on the post-NAC MRI features correlated with pCR and their association with WSI features from core needle biopsies.

Enhancing radiosensitivity in triple-negative breast cancer through targeting ELOB

Enhancing radiotherapy sensitivity is crucial for improving treatment outcomes in triple-negative breast cancer (TNBC) patients. In this study, we investigated the potential of targeting Elongin B (ELOB) to enhance radiotherapy efficacy in TNBC. Analysis of TNBC patient cohorts revealed a significant association between high ELOB expression and poor prognosis in patients who received radiation therapy. Mechanistically, we found that ELOB plays a pivotal role in regulating mitochondrial function via modulating mitochondrial DNA expression and activities of respiratory chain complexes. Targeting ELOB effectively modulated mitochondrial function, leading to enhanced radiosensitivity in TNBC cells. Our findings highlight the importance of ELOB as a potential therapeutic target for improving radiotherapy outcomes in TNBC. Further exploration of ELOB's role in enhancing radiotherapy efficacy may provide valuable insights for developing novel treatment strategies for TNBC patients.

Neoadjuvant nivolumab plus bevacizumab therapy improves the prognosis of triple-negative breast cancer in humanized mouse models

BACKGROUND

The combination of immune checkpoint inhibitors and anti-angiogenic agents has been proposed as a promising strategy to improve the outcome of advanced triple-negative breast cancer (TNBC). However, further investigation is warranted to elucidate the specific mechanisms underlying the effects of combination therapy and its potential as neoadjuvant therapy for early-stage TNBC.

METHODS

In this study, we constructed humanized mouse models by engrafting the human immune system into severely immunodeficient mice and subsequently implanting TNBC cells into the model. The mice were treated with neoadjuvant combination therapy (bevacizumab combined with nivolumab), followed by in vivo imaging system to assess tumor recurrence and metastasis after surgery. The immune microenvironment of tumors was analyzed to investigate the potential mechanisms. Furthermore, we verified the impact of extending the interval before surgery or administering adjuvant therapy after neoadjuvant therapy on the prognosis of mice.

RESULTS

Neoadjuvant combination therapy significantly inhibited tumor growth, prevented recurrence and metastasis by normalizing tumor vessels and inducing robust CD8+ T cell infiltration and activation in primary tumors (p < 0.001). In vivo experiments demonstrated that prolonging the interval before surgery or administering adjuvant therapy after neoadjuvant therapy did not enhance its efficacy.

CONCLUSION

The preclinical study has demonstrated the therapeutic efficacy and mechanism of neoadjuvant combination therapy (nivolumab plus bevacizumab) in treating early TNBC.

Pioglitazone enhances cisplatin's impact on triple-negative breast cancer: Role of PPARγ in cell apoptosis

Peroxisome proliferator-activated receptor-gamma (PPARγ) has been recently shown to play a role in many cancers. The breast tissue of triple-negative breast cancer (TNBC) patients were found to have a significantly lower expression of PPARγ than the other subtypes. Furthermore, PPARγ activation was found to exert anti-tumor effects by inhibiting cell proliferation, differentiation, cell growth, cell cycle, and inducing apoptosis. To start with, we performed a bioinformatic analysis of data from OncoDB, which showed a lower expression pattern of PPARγ in different cancer types. In addition, high expression of PPARγ was associated with better breast cancer patient survival. Therefore, we tested the impact of pioglitazone, a PPARγ ligand, on the cytotoxic activity of cisplatin in the TNBC cell line. MDA-MB-231 cells were treated with either cisplatin (40 μM) with or without pioglitazone (30 or 60 μM) for 72 h. The MTT results showed a significant dose-dependent decrease in cell viability as a result of using cisplatin and pioglitazone combination compared with cisplatin alone. In addition, the protein expression of Bcl-2, a known antiapoptotic marker, decreased in the cells treated with cisplatin and pioglitazone combination at doses of 40 and 30 μM, respectively. On the other hand, cleaved- poly-ADP ribose polymerase (PARP) and -caspase-9, which are known as pro-apoptotic markers, were upregulated in the combination group compared with the solo treatments. Taken together, the addition of pioglitazone to cisplatin further reduced the viability of MDA-MB-231 cells and enhanced apoptosis compared with chemotherapy alone.

Mammographic density changes after neoadjuvant chemotherapy in triple-negative breast cancer: Association with treatment and survival outcome

PURPOSE

To investigate the association of mammographic breast density with treatment and survival outcomes in patients with triple-negative breast cancer (TNBC) undergoing neoadjuvant chemotherapy (NAC).

METHODS

This retrospective study evaluated 306 women with TNBC who underwent NAC followed by surgery between 2010 and 2019. The baseline density and the density changes after NAC were evaluated. Qualitative breast density (a-d) was evaluated using the Breast Imaging Reporting and Data System. Quantitative breast density (%) was evaluated using fully automated software (the Laboratory for Individualized Breast Radiodensity Assessment) in the contralateral breast. Multivariable logistic regression analysis was used to evaluate the association between breast density and pathologic complete response (pCR), stratified by menopausal status. Cox proportional hazard regression analysis was used to evaluate the association among breast density, the development of contralateral breast cancer, and the development of locoregional recurrence and/or distant metastasis.

RESULTS

Contralateral density reduction ≥10 % was independently associated with pCR in premenopausal women (odds ratio [OR], 2.5; p = 0.022) but not in postmenopausal women (OR, 0.9; p = 0.823). During a mean follow-up of 65 months, 10 (3 %) women developed contralateral breast cancer, and 68 (22 %) women developed locoregional recurrences and/or distant metastases. Contralateral density reduction ≥10 % showed no association with the occurrence of contralateral breast cancer (hazard ratio [HR], 3.1; p = 0.308) or with locoregional recurrence and/or distant metastasis (HR, 1.1; p = 0.794).

CONCLUSION

In premenopausal women, a contralateral breast density reduction of ≥10 % after NAC was independently associated with pCR, although it did not translate into improved outcomes.

Circ-FOXO3 inhibits triple-negative breast cancer growth and metastasis via regulating WHSC1-H3K36me2-Zeb2 axis

Circular RNAs (circRNAs), a subclass of non-coding RNAs characterized by covalently closed continuous loops, play a key role in tumorigenesis and aggressiveness. However, the potential molecular mechanism of circRNAs in triple-negative breast cancer (TNBC) remains largely unknown. Exploring their roles and mechanisms in TNBC progression may help identify new diagnostic markers and therapeutic targets. In this study, we found that circ-FOXO3 was dramatically downregulated in TNBC tissues and blood samples from patients with TNBC. Notably, low circ-FOXO3 expression in TNBC tissues and bloods was associated with lymph node metastasis and unfavorable outcomes in patients with TNBC. Overexpression of circ-FOXO3 significantly inhibited the growth, invasion, and metastasis of TNBC cells both in vitro and in vivo. Moreover, we demonstrated that circ-FOXO3 was predominantly expressed in the cytoplasm and directly interacted with Wolf-Hirschhorn syndrome candidate 1 (WHSC1), thereby inhibiting WHSC1 nuclear localization and activity, resulting in the inhibition of H3K36me2 modifications at the Zeb2 promoter, ultimately inhibiting Zeb2 expression and halting TNBC growth and metastasis. Taken together, these results reveal the tumor-suppressive functions of circ-FOXO3 in inhibiting WHSC1-mediated H3K36me2 modification of Zeb2, suggesting that circ-FOXO3 could serve as a potential novel predictive prognostic biomarker and therapeutic target for TNBC.

Distribution of PD-L1, TROP2 and HER2- "lowness" in early triple-negative breast cancer: an opportunity for treatment de-escalation

BACKGROUND

HER2, TROP2 and PD-L1 are novel targets in triple-negative breast cancer (TNBC). The combined expression status of these targets, and whether they can define prognostic subgroups, is currently undefined.

METHODS

Immunohistochemistry was used to determine HER2, TROP2 and PD-L1 levels in 459 TNBC cases, that received in the adjuvant/neoadjuvant setting active surveillance, CMF, anthracycline-, anthracycline plus taxane-, or carboplatin-containing regimes.

RESULTS

HER2-low patients with PD-L1 > 1 CPS (double-positive, herein "DP") had a mean PFS of 4768 days (95% CI: 4267-5268) versus 3522 days (95% CI: 3184-3861) for non-DP patients (P = 0.002). Regarding the received adjuvant treatment, DP patients (versus non-DP) receiving anthracyclines plus taxanes exhibited a mean PFS time of 4726 (95% CI: 4022-5430) versus 3302 (95% CI: 2818-3785) days (P = 0.039). Finally, 100% of DP patients that received a carboplatin-based regimen were long-term disease-free.

CONCLUSIONS

Early HER2-low, PD-L1-positive TNBC patients have a very good prognosis, particularly if treated with anthracycline/taxane- or carboplatin-containing regimes.

K48-linked deubiquitination of VGLL4 by USP15 enhances the efficacy of tumor immunotherapy in triple-negative breast cancer

Immunotherapy based on PD-1/PD-L1 antagonists has been demonstrated to be efficacious in inducing tumor remission in patients with triple-negative breast cancer (TNBC). However, tumor immune evasion caused by the PD-1/PD-L1 pathway inhibits the immunotherapeutic effect of PD-1/PD-L1 inhibitors against TNBC. Therefore, identifying potential targets for blocking the PD-1/PD-L1 pathway is a compelling strategy for TNBC treatment. Here, we discovered that VGLL4 could inhibit PD-L1 transcription by suppressing STAT3 activation, thereby enhancing the efficacy of anti-PD-1 antibody immunotherapy in TNBC. Low expression of USP15, a deubiquitinating enzyme of VGLL4, was associated with reduced CD8+ T cell infiltration and poor prognosis in TNBC patients. USP15 was found to inhibit PD-L1 transcription, leading to increased CD8+ T cell infiltration and thus enhancing the efficacy of TNBC immunotherapy. Furthermore, SART3 regulated VGLL4 stability and PD-L1 transcription by influencing the nuclear translocation of USP15. In conclusion, our study provides new insights into the biological regulation of PD-L1, identifies a previously unrecognized regulator of this critical immune checkpoint, and highlights potential therapeutic targets for overcoming immune evasion in TNBC.

Impact of HER2 status on clinicopathological characteristics and pathological complete response to neoadjuvant chemotherapy in triple-negative breast cancer

PURPOSE

HER2-low triple-negative breast cancer (TNBC) accounted for up to 34%-39% of primary TNBC and 22.2%-32% of metastatic TNBC. Our study aims to explore the relationship between HER2 expression and clinicopathological characteristics, analyze the impact of HER2 expression on the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in TNBC.

METHODS

This study involved 191 patients with TNBC who underwent operation after NAC from October 2021 to August 2022. Clinicopathological characteristics and the frequency of pCR were compared between HER2-low and HER2-0 TNBC.

RESULTS

42.2% (81/191) patients in our cohort were HER2-low. They exhibited differences in menopausal status, body mass index (BMI), androgen receptor (AR) expression, and histological grade (P < 0.05). Particularly, in HER2-low TNBC, AR was associated with tumor size, lymph node metastase, histological grade, and the incidence of multifocal disease (P < 0.05). The total pCR rate of entire cohor was 39.8%. Tumor size (P = 0.025), AR status (P = 0.033) and histological grade (P = 0.007) were significantly associated with the pCR rate of them, while the HER2 status did not exert a similar association. The multivariate analysis revealed that BMI (P = 0.004) and histological grade (P < 0.001) were associated with pCR of HER2-low TNBC, while tumor size (P = 0.034) and AR (P = 0.034) were associated with pCR of HER2-0 TNBC, respectively.

CONCLUSIONS

In our cohort, HER2-low TNBC patients exhibits specific clinical characteristics and response features to NAC.

Intratumoral and Peritumoral Edema Radiomics Based on Fat-Suppressed T2- Weighted Imaging for Preoperative Prediction of Triple-Negative Breast Cancer

AIM

Our aim was to explore the feasibility of using radiomics data derived from intratumoral and peritumoral edema on fat-suppressed T2-weighted imaging (T2 FS) to distinguish triple-negative breast cancer (TNBC) from non-triple-negative breast cancer (non-TNBC).

METHODS

This retrospective study enrolled 174 breast cancer patients. According to the MRI examination time, patients before 2021 were divided into training (n = 119) or internal test (n = 30) cohorts at a ratio of 8:2. Patients from 2022 were included in the external test cohort (n = 25). Four regions of interest for each lesion were defined: intratumoral regions, peritumoral edema regions, regions with a combination of intratumoral and peritumoral edema, and regions with a combination of intratumoral and 5-mm peritumoral. Four radiomic signatures were built using the least absolute shrinkage and selection operator (LASSO) method after selecting features. Furthermore, a radio mic-radiological model was constructed using a combination of intratumoral and peritumoral edema regions along with clinical-radiologic features. Area under the receiver operating characteristic curve (AUC) calculations, decision curve analysis, and calibration curve analysis were performed to assess the performance of each model.

RESULTS

The radiomic-radiological model showed the highest AUC values of 0.906 (0.788-1.000) and 82.5 (0.622-0.947) in both the internal and external test sets, respectively. The radiology-radiomic model exhibited excellent predictive performance, as evidenced by the calibration curves and decision curve analysis.

CONCLUSION

The ensemble model based on T2 FS-based radiomic features of intratumoral and peritumoral edema, along with radiological factors, performed better in distinguishing TNBC from non-TNBC than a single model. We explored the possibility of developing explainable models to support the clinical decision-making process.

PYCR3 Modulates mtDNA Copy Number to Drive Proliferation and Doxorubicin Resistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) poses significant challenges in treatment due to its aggressive nature and limited therapeutic targets. Understanding the underlying molecular mechanisms driving TNBC progression and chemotherapy resistance is imperative for developing effective therapeutic strategies. Thus, in this study, we aimed to elucidate the role of pyrroline-5-carboxylate reductase 3 (PYCR3) in TNBC pathogenesis and therapeutic response. We observed that PYCR3 is significantly upregulated in TNBC specimens compared to normal breast tissues, correlating with a poorer prognosis in TNBC patients. Knockdown of PYCR3 not only suppresses TNBC cell proliferation but also reverses acquired resistance of TNBC cells to doxorubicin, a commonly used chemotherapeutic agent. Mechanistically, we identified the mitochondrial localization of PYCR3 in TNBC cells and demonstrated its impact on TNBC cell proliferation and sensitivity to doxorubicin through the regulation of mtDNA copy number and mitochondrial respiration. Importantly, Selective reduction of mtDNA copy number using the mtDNA replication inhibitor 2', 3'-dideoxycytidine effectively recapitulates the phenotypic effects observed in PYCR3 knockout, resulting in decreased TNBC cell proliferation and the reversal of doxorubicin resistance through apoptosis induction. Thus, our study underscores the clinical relevance of PYCR3 and highlight its potential as a therapeutic target in TNBC management. By elucidating the functional significance of PYCR3 in TNBC, our findings contribute to a deeper understanding of TNBC biology and provide a foundation for developing novel therapeutic strategies aimed at improving patient outcomes.

Synergistic effects of photodynamic therapy and chemotherapy: Activating the intrinsic/extrinsic apoptotic pathway of anoikis for triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC) is a highly invasive and metastatic subtype of breast cancer that often recurs after surgery. Herein, we developed a cyclodextrin-based tumor-targeted nano delivery system that incorporated the photosensitizer chlorin e6 (Ce6) and the chemotherapeutic agent lonidamine (LND) to form the R6RGD-CMβCD-se-se-Ce6/LND nanoparticles (RCC/LND NPS). This nanosystem could target cancer cells, avoid lysosomal degradation and further localize within the mitochondria. The RCC/LND NPS had pH and redox-responsive to control the release of Ce6 and LND. Consequently, the nanosystem had a synergistic effect by effectively alleviating hypoxia, enhancing the production of cytotoxic reactive oxygen species (ROS) and amplifying the efficacy of photodynamic therapy (PDT). Furthermore, the RCC/LND NPS + light weakened anoikis resistance, disrupted extracellular matrix (ECM), activated both the intrinsic apoptotic pathway (mitochondrial pathway) and extrinsic apoptotic pathway (receptor death pathway) of anoikis. In addition, the nanosystem showed significant anti-TNBC efficacy in vivo. These findings collectively demonstrated that RCC/LND NPS + light enhanced the anticancer effects, induced anoikis and inhibited tumor cell migration and invasion through a synergistic effect of chemotherapy and PDT. Overall, this study highlighted the promising potential of the RCC/LND NPS + light for the treatment of TNBC.

Comprehensive understanding of the role of GPER in estrogen receptor-alpha negative breast cancer

G protein-coupled estrogen receptor (GPER) plays a prominent role in facilitating the rapid, non-genomic signaling of estrogens in breast cancer cells. Herein, a comprehensive overview of the role of GPER in ER-ɑ-negative breast cancer is provided. Activation of GPER affected proliferation, metastasis and epithelial mesenchymal transition in ER-ɑ negative breast cancer cells. Clinical studies have demonstrated that GPER positivity was strongly correlated with larger tumor size and advanced clinical stage, suggesting that GPER/ERK signaling may play a role in promoting tumor progression. Strong evidence existed that environmental contaminants like bisphenol A have a carcinogenic potential mediated by GPER activation. The complexity of the cross talk between GPER and other receptors including ER-β, ER-α36, Estrogen-related receptor α (ERRα) and androgen receptor has been discussed. The potential utility of small molecules and phytoestrogens targeting GPER, adds valuable insights into its therapeutic potential. This review holds promises in advancing our understanding of GPER role in ER-ɑ-negative breast cancer. Overall, the consequences of GPER activation are still an area of active research and the implication are not entirely clear.

CCAAT enhancer binding protein delta activates vesicle associated membrane protein 3 transcription to enhance chemoresistance and extracellular PD-L1 expression in triple-negative breast cancer

BACKGROUND

Chemoresistance and immunosuppression are two major obstacles in the current anti-cancer treatments. This study investigates the involvements of a CCAAT enhancer binding protein delta (CEBPD)/vesicle associated membrane protein 3 (VAMP3) axis in paclitaxel (PTX) resistance and immune evasion in triple-negative breast cancer (TNBC).

METHODS

PTX resistance-related genes were screened by bioinformatics. CEBPD and VAMP3 expression in clinical TNBC samples was examined by immunohistochemistry. Three PTX-resistant TNBC cell lines (MDA-MB-231/PTX, MDA-MB-468/PTX and MDA-MB-453/PTX) were generated, and their drug resistance was analyzed. Autophagy of cells was analyzed by immunofluorescence staining. Interaction between CEBPD and VAMP3 promoter was identified by immunoprecipitation and luciferase assays. The extracellular expression of programmed cell death-ligand 1 (PD-L1) in TNBC cells was detected. Extracellular vesicles (EVs) from TNBC cells were isolated to examine their effects on CD8+ T cell exhaustion.

RESULTS

CEBPD and VAMP3 were upregulated in chemo-resistant tissue samples and in PTX-resistant TNBC cells. The CEBPD downregulation enhanced PTX sensitivity of cells. However, further upregulation of VAMP3 in cells restored PTX resistance, which was likely due to the activation of autophagy, as the autophagy antagonist chloroquine enhanced PTX sensitivity of cells. CEBPD was found to bind to the VAMP3 promoter to activate its transcription. The CEBPD/VAMP3 axis also increased the PD-L1 expression in the conditioned medium of TNBC cells. The TNBC cell-derived EVs increased the exhaustion of co-cultured CD8+ T cells.

CONCLUSION

This study provides novel evidence that CEBPD plays a key role in enhancing PTX resistance in TNBC cells across various subtypes through VAMP3-mediated autophagy activation. Additionally, the CEBPD/VAMP3 axis also increases extracellular PD-L1 level, delivered by cancer cell-derived EVs, to suppress CD8+ T cell-mediated anti-tumor immune response. These significant observations may provide new insights into the treatment of TNBC, suggesting CEBPD and VAMP3 as promising targets to overcome treatment resistance.

Exploring the association of POSTN+ cancer-associated fibroblasts with triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis. Cancer-associated fibroblasts (CAFs) play a critical role in regulating TNBC tumor development. This study aimed to identify and characterize a specific subtype of CAFs associated with TNBC. Initially, using high-throughput bulk transcriptomic data in two cohorts, we identified three CAF-related subtypes (CS1, CS2, CS3) in TNBC samples. These three CAFs subtypes were closely linked to the tumor microenvironment. The CS1 subtype exhibited a relatively immune-rich microenvironment and a favourable prognosis, whereas the CS3 subtype displayed an immune-deprived tumor microenvironment and an unfavourable prognosis. Through WGCNA analysis, POSTN was identified as a key biomarker for CAFs associated with TNBC. Then, POSTN+CAFs was identified and characterized. Both POSTN and POSTN+CAFs showed significant positive correlations with stromal molecules HGF and MET at both the transcriptional and protein levels. Specifically co-localized with CAFs in the tumor stromal area, POSTN, produced by POSTN+CAFs, could modulate the HGF-MET axis, serving as a bypass activation pathway to regulate tumor cell proliferation in response to EGFR inhibitor and MET inhibitor. This study underscores the significance of POSTN and POSTN+CAFs as crucial targets for the diagnosis and treatment of TNBC.

Utility of human epidermal growth factor 2 heterogeneity as a prognostic factor in triple-negative breast cancer

In some cases of human epidermal growth factor 2 (HER2)-negative breast cancer, including triple-negative breast cancer, HER2 expression is sporadically and strongly upregulated, a condition known as HER2 heterogeneity. We investigated the clinicopathological features of patients with HER2 heterogeneity in triple-negative breast cancers treated with neoadjuvant chemotherapy. Thirty-nine patients with triple-negative breast cancer who had undergone preoperative chemotherapy participated in this study. To assess for HER2 heterogeneity, we used dual in situ hybridization slides. We evaluated the association between HER2 heterogeneity and clinicopathological factors such as rates of pathologic complete response (pCR) and of recurrence-free survival. Of the 39 patients, 15 (38.5%) had cancers with HER2 heterogeneity. The pCR rates were 13.3% among patients with HER2 heterogeneity and 20.8% among those with HER2 nonheterogeneity, but the difference was not significant. The recurrence-free survival rate was significantly lower in patients with HER2 heterogeneity than in those without (P = 0.025). HER2 heterogeneity is a significant predictor of poor prognosis in patients with triple-negative breast cancer treated with neoadjuvant chemotherapy.

Datopotamab deruxtecan: A novel antibody drug conjugate for triple-negative breast cancer

Triple negative breast cancer (TNBC) represents the breast cancer subtype with least favorable outcome because of the lack of effective treatment options and its molecular features. Recently, ADCs have dramatically changed the breast cancer treatment landscape; the anti-TROP2 ADC Sacituzumab Govitecan has been approved for treatment of previously treated, metastatic TNBC patients. The novel ADC Datopotecan-deruxtecan (Dato-DXd) has recently shown encouraging results for TNBC. In the current paper, we summarize and discuss available data regarding this TROP-2 directed agent mechanism of action and pharmacologic activity, we describe first results on efficacy and safety of the drug and report characteristics, inclusion criteria and endpoints of the main ongoing clinical trials.

A prognostic model for triple-negative breast cancer patients with liver metastasis: A population-based study

However, it is still difficult for clinicians to establish prognostic stratifications and therapeutic strategies because of the lack of tools for predicting the survival of triple-negative breast cancer patients with liver metastases (TNBC-LM). Based on clinical data from large populations, a sensitive and discriminative nomogram was developed and validated to predict the prognosis of TNBC patients with LM at initial diagnosis or at the later course.

Introduction/background

Liver metastasis (LM) in TNBC patients is associated with significant morbidity and mortality. The objective of this study was to construct a clinical model to predict the survival of TNBC-LM patients.

Materials and methods

Clinicopathologic data were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database and the Fifth Affiliated Hospital of Sun Yat-Sen University (FAFSYU). Based on patients with newly diagnosed TNBC with LM (nTNBC-LM) from the SEER database, a predictive nomogram was established and validated. Its predictive effect on TNBC patients with LM at later disease course by enrolling TNBC patients from FAFSYU who developed LM later. The prognostic effect of different treatment for nTNBC-LM was further assessed.

Results

A prognostic model was developed and validated to predict the prognosis of TNBC-LM patients. For LM patients diagnosed at the initial or later treatment stage, the C-index (0.712, 0.803 and 0.699 in the training, validation and extended groups, respectively) and calibration plots showed the acceptable prognostic accuracy and clinical applicability of the nomogram. Surgical resection on the primary tumour and chemotherapy were found to be associated with significantly better overall survival (OS).

Conclusion

A sensitive and discriminative model was developed to predict OS in TNBC-LM patients both at and after initial diagnosis.

The use of a selective, nontoxic dual-acting peptide for breast cancer patients with brain metastasis

Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by the absence of commonly targeted receptors. Unspecific chemotherapy is currently the main therapeutic option, with poor results. Another major challenge is the frequent appearance of brain metastasis (BM) associated with a significant decrease in patient overall survival. The treatment of BM is even more challenging due to the presence of the blood-brain barrier (BBB). Here, we present a dual-acting peptide (PepH3-vCPP2319) designed to tackle TNBC/BM, in which a TNBC-specific anticancer peptide (ACP) motif (vCPP2319) is joined to a BBB peptide shuttle (BBBpS) motif (PepH3). PepH3-vCPP2319 demonstrated selectivity and efficiency in eliminating TNBC both in monolayers (IC50≈5.0 µM) and in spheroids (IC50≈25.0 µM), with no stringent toxicity toward noncancerous cell lines and red blood cells (RBCs). PepH3-vCPP2319 was also able to cross the BBB in vitro and penetrate the brain in vivo, and was stable in serum with a half-life above 120 min. Tumor cell-peptide interaction is fast, with quick peptide internalization via clathrin-mediated endocytosis without membrane disruption. Upon internalization, the peptide is detected in the nucleus and the cytoplasm, indicating a multi-targeted mechanism of action that ultimately induces irreversible cell damage and apoptosis. In conclusion, we have designed a dual-acting peptide capable of brain penetration and TNBC cell elimination, thus expanding the drug arsenal to fight this BC subtype and its BM.

Identification of hub genes and diagnostic efficacy for triple-negative breast cancer through WGCNA and Mendelian randomization

OBJECTIVE

Triple-negative breast cancer (TNBC) represents a particularly aggressive form of breast cancer with a poor prognosis due to a lack of targeted treatments resulting from limited a understanding of the underlying mechanisms. The aim of this study was the identification of hub genes for TNBC and assess their clinical applicability in predicting the disease.

METHODS

This study employed a combination of weighted gene co-expression network analysis (WGCNA) and differentially expressed genes (DEGs) to identify new susceptible modules and central genes in TNBC. The potential functional roles of the central genes were investigated using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. Furthermore, a predictive model and ROC curve were developed to assess the diagnostic performance of the identified central genes. The correlation between CCNB1 and immune cells proportion was also investigated. At last, a Mendelian randomization (MR) analysis utilizing Genome-Wide Association Study (GWAS) data was analyzed to establish the causal effect of CCNB1 level on TNBC.

RESULTS

WGCNA was applied to determine gene co-expression maps and identify the most relevant module. Through a screening process, 1585 candidate hub genes were subsequently identified with WGCNA and DEGs. GO and KEGG function enrichment analysis indicated that these core genes were related to various biological processes, such as organelle fission, chromosome segregation, nuclear division, mitotic cell cycle phase transition, the cell cycle, amyotrophic lateral sclerosis, and motor proteins. Using STRING and Cytoscape, the top five genes with high degrees were identified as CDC2, CCNB1, CCNA2, TOP2A, and CCNB2. The nomogram model demonstrated good performance in predicting TNBC risk and was proven effective in diagnosis, as evidenced by the receiver operating characteristic (ROC) curve. Further investigation revealed a causal association between CCNB1 and immune cell infiltrates in TNBC. Survival analysis revealed high expression of the CCNB1 gene leads to poorer prognosis in TNBC patients. Additionally, analysis using inverse variance weighting revealed that CCNB1 was linked to a 2.8% higher risk of TNBC (OR: 1.028, 95% CI 1.002-1.055, p = 0.032).

CONCLUSION

We established a co-expression network using the WGCNA methodology to detect pivotal genes associated with TNBC. This finding holds promise for advancing the creation of pre-symptomatic diagnostic tools and deepening our comprehension of the pathogenic mechanisms involved in TNBC risk genes.

Chitin-mediated blockade of chitinase-like proteins reduces tumor immunosuppression, inhibits lymphatic metastasis and enhances anti-PD-1 efficacy in complementary TNBC models

BACKGROUND

Chitinase-like proteins (CLPs) play a key role in immunosuppression under inflammatory conditions such as cancer. CLPs are enzymatically inactive and become neutralized upon binding of their natural ligand chitin, potentially reducing CLP-driven immunosuppression. We investigated the efficacy of chitin treatment in the context of triple-negative breast cancer (TNBC) using complementary mouse models. We also evaluated the immunomodulatory influence of chitin on immune checkpoint blockade (ICB) and compared its efficacy as general CLP blocker with blockade of a single CLP, i.e. chitinase 3-like 1 (CHI3L1).

METHODS

Female BALB/c mice were intraductally injected with luciferase-expressing 4T1 or 66cl4 cells and systemically treated with chitin in combination with or without anti-programmed death (PD)-1 ICB. For single CLP blockade, tumor-bearing mice were treated with anti-CHI3L1 antibodies. Metastatic progression was monitored through bioluminescence imaging. Immune cell changes in primary tumors and lymphoid organs (i.e. axillary lymph nodes and spleen) were investigated through flow cytometry, immunohistochemistry, cytokine profiling and RNA-sequencing. CHI3L1-stimulated RAW264.7 macrophages were subjected to 2D lymphatic endothelial cell adhesion and 3D lymphatic integration in vitro assays for studying macrophage-mediated lymphatic remodeling.

RESULTS

Chitin significantly reduced primary tumor progression in the 4T1-based model by decreasing the high production of CLPs that originate from tumor-associated neutrophils (TANs) and Stat3 signaling, prominently affecting the CHI3L1 and CHI3L3 primary tumor levels. It reduced immunosuppressive cell types and increased anti-tumorigenic T-cells in primary tumors as well as axillary lymph nodes. Chitin also significantly reduced CHI3L3 primary tumor levels and immunosuppression in the 66cl4-based model. Compared to anti-CHI3L1, chitin enhanced primary tumor growth reduction and anti-tumorigenicity. Both treatments equally inhibited lymphatic adhesion and integration of macrophages, thereby hampering lymphatic tumor cell spreading. Upon ICB combination therapy, chitin alleviated anti-PD-1 resistance in both TNBC models, providing a significant add-on reduction in primary tumor and lung metastatic growth compared to chitin monotherapy. These add-on effects occurred through additional increase in CD8α+ T-cell infiltration and activation in primary tumor and lymphoid organs.

CONCLUSIONS

Chitin, as a general CLP blocker, reduces CLP production, enhances anti-tumor immunity as well as ICB responses, supporting its potential clinical relevance in immunosuppressed TNBC patients.

CD24 negativity reprograms mitochondrial metabolism to PPARα and NF-κB-driven fatty acid β-oxidation in triple-negative breast cancer

CD24 is a well-characterized breast cancer (BC) stem cell (BCSC) marker. Primary breast tumor cells having CD24-negativity together with CD44-positivity is known to maintain high metastatic potential. However, the functional role of CD24 gene in triple-negative BC (TNBC), an aggressive subtype of BC, is not well understood. While the significance of CD24 in regulating immune pathways is well recognized in previous studies, the significance of CD24 low expression in onco-signaling and metabolic rewiring is largely unknown. Using CD24 knock-down and over-expression TNBC models, our in vitro and in vivo analysis suggest that CD24 is a tumor suppressor in metastatic TNBC. Comprehensive in silico gene expression analysis of breast tumors followed by lipidomic and metabolomic analyses of CD24-modulated cells revealed that CD24 negativity induces mitochondrial oxidative phosphorylation and reprograms TNBC metabolism toward the fatty acid beta-oxidation (FAO) pathway. CD24 silencing activates PPARα-mediated regulation of FAO in TNBC cells. Further analysis using reverse-phase protein array and its validation using CD24-modulated TNBC cells and xenograft models nominated CD24-NF-κB-CPT1A signaling pathway as the central regulatory mechanism of CD24-mediated FAO activity. Overall, our study proposes a novel role of CD24 in metabolic reprogramming that can open new avenues for the treatment strategies for patients with metastatic TNBC.

Sacituzumab govitecan in metastatic triple-negative breast cancer patients treated at Institut Curie Hospitals: efficacy, safety, and impact of brain metastases

BACKGROUND

Sacituzumab govitecan (SG) has been approved by FDA in April 2021 for pre-treated metastatic triple-negative breast cancer (mTNBC), following the ASCENT trial results.

METHODS

We set up an ambispective bicentric cohort study to assess the real-world effectiveness and safety of SG in patients with mTNBC treated at Institut Curie Hospitals, with a focus on patients with brain metastases.

RESULTS

This study included 99 patients treated through the French Early Access Program to SG from May 2021 to January 2023. Median age was 55 years [26-89], N = 8 patients (8%) had BRCA1/2 mutation, N = 12 (12%) de novo stage IV disease and N = 31 (31%) brain metastases. Patients had previously received a median of two [1-10] lines of treatment in advanced setting. After a median follow-up of 9.7 months, the median progression-free survival (PFS) and overall survival (OS) were 3.9 months (95%CI[3.4-5.0]) and 8.6 months (95%CI[7.1-11.9]), respectively, while objective response rate was 29% (95%CI[21-39]). Among patients with brain metastases, median PFS and OS were 3.7 months (95%CI[2.6-6.2]) and 6.7 months (95%CI[6.3-NR]), respectively, with intracranial tumor responses. Dose reductions were required in N = 17 patients (17%) within a median of three [2-11] cycles, due to gastrointestinal toxicity (N = 6; 6%), hematological toxicity (N = 9; 9%) including febrile neutropenia (N = 2; 2%), liver enzyme elevation (N = 1; 1%), and physical deterioration (N = 1; 1%). There was no related death to SG.

CONCLUSIONS

The observed response rate and safety of SG are consistent with the results of the ASCENT trial, with efficacy observed in patients with brain metastases, but observed PFS and OS are numerically shorter.

Enhancing therapeutic efficacy in luminal androgen receptor triple-negative breast cancer: exploring chidamide and enzalutamide as a promising combination strategy

Extensive exploration of the molecular subtypes of triple-negative breast cancer (TNBC) is critical for advancing precision medicine. Notably, the luminal androgen receptor (LAR) subtype has attracted attention for targeted treatment combining androgen receptor antagonists and CDK4/6 inhibitors. Unfortunately, this strategy has proven to be of limited efficacy, highlighting the need for further optimization. Using our center's comprehensive multiomics dataset (n = 465), we identified novel therapeutic targets and evaluated their efficacy through multiple models, including in vitro LAR cell lines, in vivo cell-derived allograft models and ex vivo patient-derived organoids. Moreover, we conducted flow cytometry and RNA-seq analysis to unveil potential mechanisms underlying the regulation of tumor progression by these therapeutic strategies. LAR breast cancer cells exhibited sensitivity to chidamide and enzalutamide individually, with a drug combination assay revealing their synergistic effect. Crucially, this synergistic effect was verified through in vivo allograft models and patient-derived organoids. Furthermore, transcriptomic analysis demonstrated that the combination therapeutic strategy could inhibit tumor progression by regulating metabolism and autophagy. This study confirmed that the combination of histone deacetylase (HDAC) inhibitors and androgen receptor (AR) antagonists possessed greater therapeutic efficacy than monotherapy in LAR TNBC. This finding significantly bolsters the theoretical basis for the clinical translation of this combination therapy and provides an innovative strategy for the targeted treatment of LAR TNBC.

U2AF2-SNORA68 promotes triple-negative breast cancer stemness through the translocation of RPL23 from nucleoplasm to nucleolus and c-Myc expression

BACKGROUND

Small nucleolar RNAs (snoRNAs) play key roles in ribosome biosynthesis. However, the mechanism by which snoRNAs regulate cancer stemness remains to be fully elucidated.

METHODS

SNORA68 expression was evaluated in breast cancer tissues by in situ hybridization and qRT‒PCR. Proliferation, migration, apoptosis and stemness analyses were used to determine the role of SNORA68 in carcinogenesis and stemness maintenance. Mechanistically, RNA pull-down, RNA immunoprecipitation (RIP), cell fractionation and coimmunoprecipitation assays were conducted.

RESULTS

SNORA68 exhibited high expression in triple-negative breast cancer (TNBC) and was significantly correlated with tumor size (P = 0.048), ki-67 level (P = 0.037), and TNM stage (P = 0.015). The plasma SNORA68 concentration was significantly lower in patients who achieved clinical benefit. The SNORA68-high patients had significantly shorter disease-free survival (DFS) (P = 0.036). Functionally, SNORA68 was found to promote the cell stemness and carcinogenesis of TNBC in vitro and in vivo. Furthermore, elevated SNORA68 expression led to increased nucleolar RPL23 expression and retained RPL23 in the nucleolus by binding U2AF2. RPL23 in the nucleolus subsequently upregulated c-Myc expression. This pathway was validated using a xenograft model.

CONCLUSION

U2AF2-SNORA68 promotes TNBC stemness by retaining RPL23 in the nucleolus and increasing c-Myc expression, which provides new insight into the regulatory mechanism of stemness.

Heat shock factor 1 inhibition enhances the effects of modulated electro hyperthermia in a triple negative breast cancer mouse model

Female breast cancer is the most diagnosed cancer worldwide. Triple negative breast cancer (TNBC) is the most aggressive type and there is no existing endocrine or targeted therapy. Modulated electro-hyperthermia (mEHT) is a non-invasive complementary cancer therapy using an electromagnetic field generated by amplitude modulated 13.56 MHz frequency that induces tumor cell destruction. However, we have demonstrated a strong induction of the heat shock response (HSR) by mEHT, which can result in thermotolerance. We hypothesized that inhibition of the heat shock factor 1 (HSF1) can synergize with mEHT and enhance tumor cell-killing. Thus, we either knocked down the HSF1 gene with a CRISPR/Cas9 lentiviral construct or inhibited HSF1 with a specific small molecule inhibitor: KRIBB11 in vivo. Wild type or HSF1-knockdown 4T1 TNBC cells were inoculated into the mammary gland's fat pad of BALB/c mice. Four mEHT treatments were performed every second day and the tumor growth was followed by ultrasound and caliper. KRIBB11 was administrated intraperitoneally at 50 mg/kg daily for 8 days. HSF1 and Hsp70 expression were assessed. HSF1 knockdown sensitized transduced cancer cells to mEHT and reduced tumor growth. HSF1 mRNA expression was significantly reduced in the KO group when compared to the empty vector group, and consequently mEHT-induced Hsp70 mRNA upregulation diminished in the KO group. Immunohistochemistry (IHC) confirmed the inhibition of Hsp70 upregulation in mEHT HSF1-KO group. Demonstrating the translational potential of HSF1 inhibition, combined therapy of mEHT with KRIBB11 significantly reduced tumor mass compared to either monotherapy. Inhibition of Hsp70 upregulation by mEHT was also supported by qPCR and IHC. In conclusion, we suggest that mEHT-therapy combined with HSF1 inhibition can be a possible new strategy of TNBC treatment with great translational potential.

SOD1-high fibroblasts derived exosomal miR-3960 promotes cisplatin resistance in triple-negative breast cancer by suppressing BRSK2-mediated phosphorylation of PIMREG

Platinum-based neoadjuvant therapy represented by cisplatin is widely employed in treating Triple-Negative Breast Cancer (TNBC), a particularly aggressive subtype of breast cancer. Nevertheless, the emergence of cisplatin resistance presents a formidable challenge to clinical chemotherapy efficacy. Herein, we revealed the critical role of tumor microenvironment (TME) derived exosomal miR-3960 and phosphorylation at the S16 site of PIMREG in activating NF-κB signaling pathway and promoting cisplatin resistance of TNBC. Detailed regulatory mechanisms revealed that SOD1-upregulated fibroblasts secrete miR-3960 and are then transported into TNBC cells via exosomes. Within TNBC cells, miR-3960 targets and inhibits the expression of BRSK2, an AMPK protein kinase family member. Furthermore, we emphasized that BRSK2 contributes to ubiquitination degradation of PIMREG and modulates subsequent activation of the NF-κB signaling pathway by mediating PIMREG phosphorylation at the S16 site, ultimately affects the cisplatin resistance of TNBC. In conclusion, our research demonstrated the crucial role of SOD1high fibroblast, exosomal miR-3960 and S16 site phosphorylated PIMREG in regulating the NF-κB signaling pathway and cisplatin resistance of TNBC. These findings provided significant potential as biomarkers for accurately diagnosing cisplatin-resistant TNBC patients and guiding chemotherapy strategy selection.

Oncolytic adenovirus encoding apolipoprotein A1 suppresses metastasis of triple-negative breast cancer in mice

BACKGROUND

Dysregulation of cholesterol metabolism is associated with the metastasis of triple-negative breast cancer (TNBC). Apolipoprotein A1 (ApoA1) is widely recognized for its pivotal role in regulating cholesterol efflux and maintaining cellular cholesterol homeostasis. However, further exploration is needed to determine whether it inhibits TNBC metastasis by affecting cholesterol metabolism. Additionally, it is necessary to investigate whether ApoA1-based oncolytic virus therapy can be used to treat TNBC.

METHODS

In vitro experiments and mouse breast cancer models were utilized to evaluate the molecular mechanism of ApoA1 in regulating cholesterol efflux and inhibiting breast cancer progression and metastasis. The gene encoding ApoA1 was inserted into the adenovirus genome to construct a recombinant adenovirus (ADV-ApoA1). Subsequently, the efficacy of ADV-ApoA1 in inhibiting the growth and metastasis of TNBC was evaluated in several mouse models, including orthotopic breast cancer, spontaneous breast cancer, and human xenografts. In addition, a comprehensive safety assessment of Syrian hamsters and rhesus monkeys injected with oncolytic adenovirus was conducted.

RESULTS

This study found that dysregulation of cholesterol homeostasis is critical for the progression and metastasis of TNBC. In a mouse orthotopic model of TNBC, a high-cholesterol diet promoted lung and liver metastasis, which was associated with keratin 14 (KRT14), a protein responsible for TNBC metastasis. Furthermore, studies have shown that ApoA1, a cholesterol reverse transporter, inhibits TNBC metastasis by regulating the cholesterol/IKBKB/FOXO3a/KRT14 axis. Moreover, ADV-ApoA1 was found to promote cholesterol efflux, inhibit tumor growth, reduce lung metastasis, and prolonged the survival of mice with TNBC. Importantly, high doses of ADV-ApoA1 administered intravenously and subcutaneously were well tolerated in rhesus monkeys and Syrian hamsters.

CONCLUSIONS

This study provides a promising oncolytic virus treatment strategy for TNBC based on targeting dysregulated cholesterol metabolism. It also establishes a basis for subsequent clinical trials of ADV-ApoA1 in the treatment of TNBC.

Identification of a Group of Therapeutic Targets and Prognostic Biomarker for Triple Negative Breast Cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) is a highly heterogeneous disease. Mining differentially expressed genes of TNBC is helpful to explore new therapeutic targets. This study aimed to investigate diagnostic biomarker genes in TNBC compared to normal tissue. Additionally, we explored the functions and prognostic value of these key genes as well as potential targeted drugs that could affect these genes.

METHODS

Differential gene expression analysis was conducted using the R software with data from the Gene Expression Omnibus (GEO) database. Then, the identified differentially expressed genes (DEGs) were used to construct a protein-protein interaction (PPI) network using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. The mRNA expression levels of key genes were analyzed using the UALCAN database with data from The Cancer Genome Atlas (TCGA). Enrichment and survival analyses were performed using R software. In addition, potential compounds showing sensitivity to key genes were identified by gene set cancer analysis (GSCA).

RESULTS

Compared with normal tissues, a total of 203 DEGs were upregulated in TNBC. These DEGs participated in various biological processes including nuclear division, microtubule binding, cell cycle, and the p53 signaling pathway. Through the PPI network analysis, ten key genes were identified, among which four genes showed significant correlation with poor progression-free interval (PFI) in patients with TNBC. Moreover, the four survival-related genes were found to act as sensitive therapeutic targets.

CONCLUSION

The identified four key genes were considered new biomarkers for diagnosis and prognosis and also potential therapeutic targets for TNBC.

Clinical characteristics associated with efficacy and prognosis among patients treated with PD-1/PD-L1 inhibitors for early-stage triple-negative breast cancers: A meta-analysis

OBJECTIVE

To assess the efficacy of PD-1/PD-L1 inhibitors combined with chemotherapy for early-stage triple-negative breast cancer (TNBC) patients with different clinical characteristics.

METHODS

Randomized clinical trials for PD-1/PD-L1 inhibitors and chemotherapy combination were included. Pooled analysis of odds ratio (OR) for pathological complete response (pCR) and hazard ratio (HR) for event-free survival (EFS) was conducted overall and for predefined subgroups.

RESULTS

The combination of immunotherapy and chemotherapy significantly improved pCR rate in early TNBC patients (OR, 1.77), and the incidence of events was significantly reduced by 37%. Lymph node metastasis was associated with more benefits on pCR (OR[N0], 1.29; OR[N+], 2.57; P = 0.01), while earlier T stage was related to more benefits on EFS (HR[T1-T2], 0.48; HR[T3-T4], 0.85; P = 0.05).

CONCLUSION

The addition of PD-1/PD-L1 inhibitors to chemotherapy offers improved pCR and EFS in early TNBC patients. T and N stages may have implications for the efficacy.

WTAP Mediates NUPR1 Regulation of LCN2 Through m6A Modification to Influence Ferroptosis, Thereby Promoting Breast Cancer Proliferation, Migration and Invasion

Ferroptosis is involved in various pathophysiological diseases, including triple-negative breast cancer (TNBC). Targeting ferroptosis is considered as a novel anti-TNBC strategy. Nevertheless, the regulatory mechanism of ferroptosis during TNBC progression is unclear. Here, the role of WTAP in ferroptosis during TNBC progression  was investigated. The clinicopathological significance of WTAP, NUPR1 and LCN2 was analyzed by Kaplan-Meier method. Cell viability was assessed using MTT assay. Transwell assay was employed to analyze cell migration and invasion. GSH/GSSG and Fe2+ levels in TNBC cells were analyzed using kits. m6A level was examined using m6A dot blot assay. NUPR1 mRNA stability was analyzed using RNA degradation assay. RIP was performed to analyze the interaction between eIF3a and NURP1. Herein, our results revealed that WTAP, NUPR1 and LCN2 expressions were significantly elevated in TNBC. NUPR1 silencing inhibited TNBC cell proliferation, migration and invasion by inducing ferroptosis. NUPR1 positively regulated LCN2 expression in TNBC cells, and LCN2 knockdown induced ferroptosis to suppress TNBC cell malignant behaviors. Our molecular study further revealed that WTAP promoted NUPR1 expression in an m6A-EIF3A mediated manner. And, as expected, WTAP knockdown promoted ferroptosis to suppress TNBC cell malignant behaviors, which were abrogated by NUPR1 overexpression. WTAP upregulated LCN2 by regulation of NUPR1 m6A modification, thereby suppressing ferroptosis to contribute to accelerate TNBC progression. Our study revealed the cancer-promoting effect of WTAP, NUPR1 and LCN2 in TNBC and clarified the relevant mechanism, providing a theoretical basis for developing novel diagnostic and therapeutic strategies for TNBC.

Synthesis of Indole-Linked Thiadiazoles and their Anticancer Action against Triple-Negative Breast Cancer

With a lack of targeted therapy and significantly high metastasis, heterogeneity, and relapse rates, Triple-Negative Breast Cancer (TNBC) offers substantial treatment challenges and demands more chemotherapeutic interventions. In the present study, indole-endowed thiadiazole derivatives have been synthesized and screened for antiproliferative potency against the triple-negative breast cancer MDA-MB-231 cell line. Compound 4 h, possessing chlorophenyl moiety, displays the best anticancer potency (IC50: 0.43 μM) in the cell viability assay. The title compounds demonstrate substantial docking competency against the EGFR receptor (PDB ID: 3POZ), validating their in-vitro ant proliferative action. With a high docking score (-9.9 to -8.7 kcal/mol), the indole hybrids display significant binding propensity comparable to the co-crystallized ligand TAK-285 and occupy a similar strategic position in the active domain of the designated receptor. The quantum and electronic properties of the integrated templates are evaluated through DFT, and optimal values of the deduced global reactivity indices, such as energy gap, electronegativity, ionization potential, chemical potential, electrophilicity, etc., suggest their apt biochemical reactivity. The indole hybrids show near-appropriate pharmacokinetic efficacy and bioavailability in the in-silico studies, indicating their candidacy for potential drug usage. Promising in-vitro anticancer action and binding interfaces project indole conjugates as potential leads in addressing the TNBC dilemma.

EPAC inhibitor suppresses angiogenesis and tumor growth of triple-negative breast cancer

AIMS

Exchange protein directly activated by cAMP 1 (EPAC1), a major isoform of guanine nucleotide exchange factors, is highly expressed in vascular endothelia cells and regulates angiogenesis in the retina. High intratumor microvascular densities (MVD) resulting from angiogenesis is responsible for breast cancer development. Downregulation of EPAC1 in tumor cell reduces triple-negative breast cancer (TNBC)-induced angiogenesis. However, whether Epac1 expressed in vascular endothelial cells contributes to angiogenesis and tumor development of TNBC remains elusive.

MAIN METHODS

We employed NY0123, a previously identified potent EPAC inhibitor, to explore the anti-angiogenic biological role of EPAC1 in vitro and in vivo through vascular endothelial cells, rat aortic ring, Matrigel plug, and chick embryo chorioallantoic membrane (CAM) and yolk sac membrane (YSM) assays, as well as the in vivo xenograft tumor models of TNBC in both chick embryo and mice.

KEY FINDINGS

Inhibiting EPAC1 in vascular endothelial cells by NY0123 significantly suppresses angiogenesis and tumor growth of TNBC. In addition, NY0123 possesses a better inhibitory efficacy than ESI-09, a reported specific EPAC inhibitor tool compound. Importantly, inhibiting EPAC1 in vascular endothelia cells regulates the typical angiogenic signaling network, which is associated with not only vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor-2 (VEGFR2) signaling, but also PI3K/AKT, MEK/ERK and Notch pathway.

CONCLUSIONS

Our findings support that EPAC1 may serve as an effective anti-angiogenic therapeutic target of TNBC, and EPAC inhibitor NY0123 has the therapeutic potential to be developed for the treatment of TNBC.

Endogenous pAKT activity is associated with response to AKT inhibition alone and in combination with immune checkpoint inhibition in murine models of TNBC

Triple-negative breast cancer (TNBC) is a heterogeneous and challenging-to-treat breast cancer subtype. The clinical introduction of immune checkpoint inhibitors (ICI) for TNBC has had mixed results, and very few patients achieved a durable response. The PI3K/AKT pathway is frequently mutated in breast cancer. Given the important roles of the PI3K pathway in immune and tumor cell signaling, there is an interest in using inhibitors of this pathway to increase the response to ICI. This study sought to determine if AKT inhibition could enhance the response to ICI in murine TNBC models. We further sought to understand underlying mechanisms of response or non-response to AKT inhibition in combination with ICI. Using four murine TNBC-like cell lines and corresponding orthotopic mouse tumor models, we found that hyperactivity of the PI3K pathway, as evidenced by levels of phospho-AKT rather than PI3K pathway mutational status, was associated with response to AKT inhibition alone and in combination with ICI. Additional mutations in other growth regulatory pathways could override the response of PI3K pathway mutant tumors to AKT inhibition. Furthermore, we observed that AKT inhibition enhanced the response to ICI in an already sensitive model. However, AKT inhibition failed to convert ICI-resistant tumors, to responsive tumors. These findings suggest that analysis of both the mutational status and phospho-AKT protein levels may be beneficial in predicting which TNBC tumors will respond to AKT inhibition in combination with ICI.

Reciprocal regulation of forkhead box C1 and L1 cell adhesion molecule contributes to triple-negative breast cancer progression

PURPOSE

The potential of targeting forkhead box C1 (FOXC1) as a therapeutic approach for triple-negative breast cancer (TNBC) is promising. However, a comprehensive understanding of FOXC1 regulation, particularly upstream factors, remains elusive. Expression of the L1 cell adhesion molecule (L1CAM), a transmembrane glycoprotein associated with brain metastasis, was observed to be positively associated with FOXC1 transcripts. Thus, this study aims to investigate their relationship in TNBC progression.

METHODS

Publicly available FOXC1 and L1CAM transcriptomic data were obtained, and their corresponding proteins were analyzed in four TNBC cell lines. In BT549 cells, FOXC1 and L1CAM were individually silenced, while L1CAM was overexpressed in BT549-shFOXC1, MDA-MB-231, and HCC1937 cells. CCK-8, transwell, and wound healing assays were performed in these cell lines, and immunohistochemical staining was conducted in tumor samples.

RESULTS

A positive correlation between L1CAM and FOXC1 transcripts was observed in publicly available datasets. In BT549 cells, knockdown of FOXC1 led to reduced L1CAM expression at both the transcriptional and protein levels, and conversely, silencing of L1CAM decreased FOXC1 protein levels, but interestingly, FOXC1 transcripts remained largely unaffected. Overexpressing L1CAM resulted in increased FOXC1 protein expression without significant changes in FOXC1 mRNA levels. This trend was also observed in BT549-shFOXC1, MDA-MB-231-L1CAM, and HCC1937-L1CAM cells. Notably, alterations in FOXC1 or L1CAM levels corresponded to changes in cell proliferation, migration, and invasion capacities. Furthermore, a positive correlation between L1CAM and FOXC1 protein expression was detected in human TNBC tumors.

CONCLUSION

FOXC1 and L1CAM exhibit co-regulation at the protein level, with FOXC1 regulating at the transcriptional level and L1CAM regulating at the post-transcriptional level, and together they positively influence cell proliferation, migration, and invasion in TNBC.

iRGD mediated pH-responsive mesoporous silica enhances drug accumulation in tumors

The limited penetration of nanocarriers into tumors and the slow release of drugs from these carriers to tumor cells are significant challenges in cancer therapy. In this study, we developed a novel drug delivery carrier derived from mesoporous silica, dually modified with the tumor-homing cyclic peptide iRGD (CRGDKGPDC) and the pH-responsive polymer poly(2-ethyl-2-oxazoline) (PEOz) for treating triple-negative breast cancer. The carrier selectively bound to the αvβ3 integrin receptor, which is specifically expressed in MDA-MB-231 breast cancer cells and vessels. Subsequently, it penetrated deep into the tumor parenchyma through NRP-1 receptor-dependent internalization, with the drug-loaded particles releasing drugs rapidly in the acidic cytoplasmic environment. Results indicated that the drug release rate of PEOz-modified formulations was pH-dependent. Lysosomal escape experiments demonstrated that PEOz-modified particles efficiently escaped lysosomes to release drugs. In vitro cytotoxicity assays revealed that iRGD-functionalized particles were more cytotoxic to NRP-1-positive MDA-MB-231 cells compared to NRP-1-negative MCF-7 cells. Cellular uptake studies demonstrated that iRGD mediated enhanced endocytosis of nanoparticles into MDA-MB-231 cells. In vitro tumor cell spheroid penetration assays confirmed that the PEOz and iRGD dual-modified carrier facilitated deeper distribution of DOX in multicellular spheroids compared to free DOX. Moreover, in a nude mouse model of triple-negative breast cancer, the dual-modified drug-loaded carrier significantly inhibited tumor growth without inducing weight loss or liver and kidney damage. This dual-modified mesoporous silica presents a novel and promising delivery carrier for enhancing cancer treatment.

Spermatid perinuclear RNA-binding protein promotes UBR5-mediated proteolysis of Dicer to accelerate triple-negative breast cancer progression

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer with no targeted therapy. Spermatid perinuclear RNA binding protein (STRBP), a poorly characterized RNA-binding protein (RBP), has an essential role in normal spermatogenesis and sperm function, but whether and how its dysregulation contributing to cancer progression has not yet been explored. Here, we report that STRBP functions as a novel oncogene to drive TNBC progression. STRBP expression was upregulated in TNBC tissues and correlated with poor disease prognosis. Functionally, STRBP promoted TNBC cell proliferation, migration, and invasion in vitro, and enhanced xenograft tumor growth and lung colonization in mice. Mechanistically, STRBP interacted with Dicer, a core component of the microRNA biogenesis machinery, and promoted its proteasomal degradation through enhancing its interaction with E3 ubiquitin ligase UBR5. MicroRNA-sequencing analysis identified miR-200a-3p as a downstream effector of STRBP, which was regulated by Dicer and affected epithelial-mesenchymal transition. Importantly, the impaired malignant phenotypes of TNBC cells caused by STRBP depletion were largely rescued by knockdown of Dicer, and these effects were compromised by transfection of miR-200a-3p mimics. Collectively, these findings revealed a previously unrecognized oncogenic role of STRBP in TNBC progression and identified STRBP as a promising target against TNBC.

Docking and Molecular Dynamics Simulation Revealed the Potential Inhibitory Activity of Amygdalin in Triple-Negative Breast Cancer Therapeutics Targeting the BRCT Domain of BARD1 Receptor

Triple-negative breast cancer (TNBC), is diagnosed as the most lethal molecular subtype of breast cancer (BC) preceded by an extremely poor prognosis. For enabling effective TNBC therapy, the identification of novel druggable biomarkers is an earnest need. Multigene paneling and genomewide association studies identify multiple genes with high-to-moderate penetrance in TNBC. Modern computer-aided drug designing techniques, thus aim to design more cost-effective natural small molecule inhibitors for TNBC prevention and diagnosis. Here Amygdalin, a natural glycosidic inhibitor is docked and simulated against three such high-to-moderate penetrance genes identified in TNBC, BARD1, RAD51, and PALB2. The preliminary result of the analysis, reports a highest, intermediate, and least binding energy score of - 6.69 kcal/mol, - 5.09 kcal/mol, and - 4.89 kcal/mol in BARD1, RAD51, and PALB2, respectively. The best-docked protein-ligand complex (BARD1-Amygdalin) was then simulated and compared with an approved drug for TNBC treatment, Olaparib. A comparable binding energy score of - 8.53 kcal/mol was obtained by docking olaparib with BARD1. A 100 ns MD simulation revealed, Amygdalin forms more H-bonds, providing more stable and compact protein-ligand complex with BARD1 than compared to Olaparib. The result was also supported by calculation of solvent accessible surface area and analysis of radius of gyration. Thus, our findings suggest that role of Amygdalin can further be studied in details for TNBC therapeutics, which was found to target the BRCT domain of the BARD1 receptor in stable manner. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. Name and affiliations are correctly identified.

The molecular subtyping and precision medicine in triple-negative breast cancer---based on Fudan TNBC classification

Triple-negative breast cancer (TNBC) is widely recognized as the most aggressive form of breast cancer, occurring more frequently in younger patients and characterized by high heterogeneity, early distant metastases and poor prognosis. Multiple treatment options have failed to achieve the expected therapeutic effects due to the lack of clear molecular targets. Based on genomics, transcriptomics and metabolomics, the multi-omics analysis further clarifies TNBC subtyping, which provides a greater understanding of tumour heterogeneity and targeted therapy sensitivity. For instance, the luminal androgen receptor subtype (LAR) exhibits responsiveness to anti-AR therapy, and the basal-like immune-suppressed subtype (BLIS) tends to benefit from poly (ADP-ribose) polymerase inhibitors (PARPis) and anti-angiogenic therapy. The efficacy of multi-dimensional combination therapy holds immense importance in guiding personalized and precision medicine for TNBC. This review offers a systematic overview of recent FuDan TNBC molecular subtyping and its role in the instruction of clinical precision therapy.

Ononin triggers ferroptosis-mediated disruption in the triple negative breast cancer both in vitro and in vivo

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is difficult to treat due to a lack of targeted therapies. In this study, we aimed to investigate whether a natural flavonoid compound called ononin could be effective in treating TNBC by triggering ferroptosis in MDA-MB-231 and 4 T1 cell lines, and MDA-MB-231-xenograft nude mice model. Ononin inhibited TNBC through ferroptosis, which was determined by MTT assay, flow cytometry, RT-PCR, immunofluorescence, transmission electron microscopy, histological analysis, western blot and bioluminescence assay. Our results showed that treatment with ononin led to increased levels of malondialdehyde and reactive oxygen species and decreased activity of superoxide dismutase, which are indicatives of ferroptosis. We also found that ononin downregulated two key markers of ferroptosis, SLC7A11 and Nrf2, at both the transcriptional and translational level. Additionally, the administration of ononin resulted in a notable decrease in tumor size and weight in the mouse model. Furthermore, it was observed to enhance the rate of apoptosis in TNBC cells. Importantly, ononin did not induce any histological changes in the kidney, liver, and heart. Taken together, our findings suggest that ononin could be a promising therapeutic strategy for TNBC, and that it works by disrupting the Nrf2/SLC7A11 axis through ferroptosis. These results are encouraging and may lead to the development of new treatments for this challenging cancer subtype.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comment on "A novel super-enhancer-related gene signature predicts prognosis and immune microenvironment for breast cancer"

The primary aim of this study is to critically evaluate and comment on the research presented in the article titled "A Novel Super-Enhancer-Related Gene Signature Predicts Prognosis and Immune Microenvironment for Breast Cancer" by Wu et al. Our specific objectives include assessing the methodology employed by the authors, particularly in regard to the utilization of a super-enhancer-related gene signature for breast cancer prognosis prediction. We propose the necessity of subgroup analysis to effectively address the heterogeneity in breast cancer subtypes, which is crucial for the applicability of the SERGs across diverse breast cancer cases. Additionally, we suggest conducting a more comprehensive immune panel study to deepen the understanding of how the immune microenvironment impacts breast cancer prognosis. Our commentary seeks to provide valuable insights into the strengths and weaknesses of the study, contributing to a more comprehensive understanding of its findings and potential clinical implications.

LINC00115 promotes chemoresistant breast cancer stem-like cell stemness and metastasis through SETDB1/PLK3/HIF1α signaling

BACKGROUND

Cancer stem-like cell is a key barrier for therapeutic resistance and metastasis in various cancers, including breast cancer, yet the underlying mechanisms are still elusive. Through a genome-wide lncRNA expression profiling, we identified that LINC00115 is robustly upregulated in chemoresistant breast cancer stem-like cells (BCSCs).

METHODS

LncRNA microarray assay was performed to document abundance changes of lncRNAs in paclitaxel (PTX)-resistant MDA-MB-231 BCSC (ALDH+) and non-BCSC (ALDH-). RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to determine the binding proteins of LINC00115. The clinical significance of the LINC00115 pathway was examined in TNBC metastatic lymph node tissues. The biological function of LINC00115 was investigated through gain- and loss-of-function studies. The molecular mechanism was explored through RNA sequencing, mass spectrometry, and the CRISPR/Cas9-knockout system. The therapeutic potential of LINC00115 was examined through xenograft animal models.

RESULTS

LINC00115 functions as a scaffold lncRNA to link SETDB1 and PLK3, leading to enhanced SETDB1 methylation of PLK3 at both K106 and K200 in drug-resistant BCSC. PLK3 methylation decreases PLK3 phosphorylation of HIF1α and thereby increases HIF1α stability. HIF1α, in turn, upregulates ALKBH5 to reduce m6A modification of LINC00115, resulting in attenuated degradation of YTHDF2-dependent m6A-modified RNA and enhanced LINC00115 stability. Thus, this positive feedback loop provokes BCSC phenotypes and enhances chemoresistance and metastasis in triple-negative breast cancer. SETDB1 inhibitor TTD-IN with LINC00115 ASO sensitizes PTX-resistant cell response to chemotherapy in a xenograft animal model. Correlative expression of LINC00115, methylation PLK3, SETDB1, and HIF1α are prognostic for clinical triple-negative breast cancers.

CONCLUSIONS

Our findings uncover LINC00115 as a critical regulator of BCSC and highlight targeting LINC00115 and SETDB1 as a potential therapeutic strategy for chemotherapeutic resistant breast cancer.

Unlocking the effective alliance of β-lapachone and hydroxytyrosol against triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is characterised by its aggressiveness and resistance to chemotherapy, demanding the development of effective strategies against its unique characteristics. Derived from lapacho tree bark, β-lapachone (β-LP) selectively targets cancer cells with elevated levels of the detoxifying enzyme NQO1. Hydroxytyrosol (HT) is a phenolic compound derived from olive trees with important anticancer properties that include the inhibition of cancer stem cells (CSCs) and metastatic features in TNBC, as well as relevant antioxidant activities by mechanisms such as the induction of NQO1. We aimed to study whether these compounds could have synergistic anticancer activity in TNBC cells and the possible role of NQO1. For this pourpose, we assessed the impact of β-LP (0.5 or 1.5 μM) and HT (50 and 100 μM) on five TNBC cell lines. We demonstrated that the combination of β-LP and HT exhibits anti-proliferative, pro-apoptotic, and cell cycle arrest effects in several TNBC cells, including docetaxel-resistant TNBC cells. Additionally, it effectively inhibits the self-renewal and clonogenicity of CSCs, modifying their aggressive phenotype. However, the notable impact of the β-LP-HT combination does not appear to be solely associated with the levels of the NQO1 protein and ROS. RNA-Seq analysis revealed that the combination's anticancer activity is linked to a strong induction of endoplasmic reticulum stress and apoptosis through the unfolded protein response. In conclusion, in this study, we demonstrated how the combination of β-LP and HT could offer an affordable, safe, and effective approach against TNBC.

Comparative study of weekly and three-weekly neoadjuvant carboplatin in triple-negative breast cancer: retrospective analysis in real-world settings

PURPOSE

Tri-weekly carboplatin is an established neoadjuvant treatment for triple-negative breast cancer, enhancing pathological complete response (pCR) and overall survival. This study explores if weekly carboplatin provides lower toxicity and comparable pCR rates.

METHODS/PATIENTS

A retrospective multicenter study (January 2021 to March 2023) compares outcomes of weekly and tri-weekly carboplatin.

RESULTS

Among 104 participants, 60% received weekly and 40% tri-weekly treatments. Weekly administration had fewer discontinuations (56.5 vs. 70.7%, p = 0.154). Both schedules exhibited similar overall toxicity (p = 0.087), with slightly higher grade 3-4 toxicity in the tri-weekly group (56.1 vs. 48.4%, p = 0.126). Hematological toxicity was comparable, but the weekly group experienced more diarrhea (p = 0.432) and asthenia (p = 0.012). Weekly treatment correlated with more frequent breast-conserving surgeries (p = 0.004). pCR rates were 50% with weekly and 61% with tri-weekly regimens (p = 0.186).

CONCLUSIONS

Weekly carboplatin exhibited comparable toxicity, a trend toward fewer interruptions, and similar pCR rates. Prospective studies are essential for validating these findings.

Factors associated with engraftment success of patient-derived xenografts of breast cancer

BACKGROUND

Patient-derived xenograft (PDX) models serve as a valuable tool for the preclinical evaluation of novel therapies. They closely replicate the genetic, phenotypic, and histopathological characteristics of primary breast tumors. Despite their promise, the rate of successful PDX engraftment is various in the literature. This study aimed to identify the key factors associated with successful PDX engraftment of primary breast cancer.

METHODS

We integrated clinicopathological data with morphological attributes quantified using a trained artificial intelligence (AI) model to identify the principal factors affecting PDX engraftment.

RESULTS

Multivariate logistic regression analyses demonstrated that several factors, including a high Ki-67 labeling index (Ki-67LI) (p < 0.001), younger age at diagnosis (p = 0.032), post neoadjuvant chemotherapy (NAC) (p = 0.006), higher histologic grade (p = 0.039), larger tumor size (p = 0.029), and AI-assessed higher intratumoral necrosis (p = 0.027) and intratumoral invasive carcinoma (p = 0.040) proportions, were significant factors for successful PDX engraftment (area under the curve [AUC] 0.905). In the NAC group, a higher Ki-67LI (p < 0.001), lower Miller-Payne grade (p < 0.001), and reduced proportion of intratumoral normal breast glands as assessed by AI (p = 0.06) collectively provided excellent prediction accuracy for successful PDX engraftment (AUC 0.89).

CONCLUSIONS

We found that high Ki-67LI, younger age, post-NAC status, higher histologic grade, larger tumor size, and specific morphological attributes were significant factors for predicting successful PDX engraftment of primary breast cancer.

Identification and validation of neutrophils-related subtypes and prognosis model in triple negative breast cancer

BACKGROUND

Neutrophils are considered to be crucial players in the initiation and progression of cancer. However, the complex relationship between neutrophils and cancer prognosis remains elusive, mainly due to the significant plasticity and diversity exhibited by these immune cells.

METHODS

As part of our thorough investigation, we examined 38 Neutrophils-Related Genes (NRGs) and the associated copy number variations (CNV), somatic mutations, and gene expression patterns in relation to triple negative breast cancer (TNBC). The interactions between these genes, their biological roles, and their possible prognostic significance were then examined. With the NRGs as our basis, we applied Lasso and Cox regression analyses to create a predictive model for overall survival (OS). Furthermore, TNBC tissue and a public database were used to assess changes in MYO1D expression (MYO1D is characterized as a member of the myosin-I family, a group of motor proteins based on actin), its connection to neutrophil infiltration, and the clinical importance of MYO1D in TNBC.

RESULTS

Four neutrophil-related genes were included in the development of a prognostic model based on neutrophils. The model was further shown to be an independent predicted factor for overall survival by multivariate Cox regression analysis. According to this study, neutrophil subtype B as well as gene subtype B, were associated with activated cancer immunity and poor prognosis of TNBC patients. Furthermore, considering that poor OS was linked to increased MYO1D expression, MYO1D was increased in TNBC tissues and associated with neutrophil infiltration. In vitro experiments also confirmed that MYO1D facilitates breast cancer invasion and metastasis.

CONCLUSION

Based on the degree of gene expression linked to neutrophils, a unique prognostic model was created. MYO1D could be a potential prognostic biomarker in TNBC patients and also a prospective target for therapy.