Progress in systemic therapy for triple-negative breast cancer

Advances in Doxorubicin-based nano-drug delivery system in triple negative breast cancer

Triple positive breast cancer (TPBC) is one of the most aggressive breast cancer. Due to the unique cell phenotype, aggressiveness, metastatic potential and lack of receptors or targets, chemotherapy is the choice of treatment for TNBC. Doxorubicin (DOX), one of the representative agents of anthracycline chemotherapy, has better efficacy in patients with metastatic TNBC (mTNBC). DOX in anthracycline-based chemotherapy regimens have higher response rates. Nano-drug delivery systems possess unique targeting and ability of co-load, deliver and release chemotherapeutic drugs, active gene fragments and immune enhancing factors to effectively inhibit or kill tumor cells. Therefore, advances in nano-drug delivery systems for DOX therapy have attracted a considerable amount of attention from researchers. In this article, we have reviewed the progress of nano-drug delivery systems (e.g., Nanoparticles, Liposomes, Micelles, Nanogels, Dendrimers, Exosomes, etc.) applied to DOX in the treatment of TNBC. We also summarize the current progress of clinical trials of DOX combined with immune checkpoint inhibitors (ICIS) for the treatment of TNBC. The merits, demerits and future development of nanomedicine delivery systems in the treatment of TNBC are also envisioned, with the aim of providing a new class of safe and efficient thoughts for the treatment of TNBC.

TCL1A+ B cells predict prognosis in triple-negative breast cancer through integrative analysis of single-cell and bulk transcriptomic data

Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and high mortality rates. It remains a prevailing clinical need to distinguish whether the patient can benefit from therapy, such as chemotherapy. By integrating single-cell and global transcriptome data, we have for the first time identified TCL1A+ B cell functions that are prognostically relevant in TNBC. This finding broadens the perspective of traditional tumor-infiltrating lymphocytes in predicting survival, especially the potential value of B cells in TNBC. Single-cell RNA-seq data from five TNBC patients were collected to identify the association between immune cell populations and clinical outcomes. Functional analysis was according to gene set enrichment analysis using pathways from MsigDB. Subsequently, the gene signature of TCL1A+ B cells based on differential expression genes of TCL1A+ B cells versus other immune cells was used to explore the correlation with tumor microenvironment (TME) and construct a prognostic signature using a non-parametric and unsupervised method. We identified TCL1A+ B cells as a cluster of B cells associated with clinical outcomes in TNBC. Functional analysis demonstrated its function in B cell activation and regulation of immune response. The highly enriched TCL1A+ B cell population was found to be associated with a thermal TME with anti-tumor effects. A high abundance of TCL1A+ B cell population is positively correlated with a favorable therapeutic outcome, as indicated by longer overall survival. The present study suggests that TCL1A+ B cells play a key role in the treatment and prognostic prediction of TNBC, although further studies are needed to validate our findings. Moreover, the integration of transcriptome data at various resolutions provides a viable approach for the discovery of novel prognostic markers.

Immune Biomarkers in Triple-Negative Breast Cancer: Improving the Predictivity of Current Testing Methods

Triple-negative breast cancer (TNBC) poses a significant challenge in terms of prognosis and disease recurrence. The limited treatment options and the development of resistance to chemotherapy make it particularly difficult to manage these patients. However, recent research has been shifting its focus towards biomarker-based approaches for TNBC, with a particular emphasis on the tumor immune landscape. Immune biomarkers in TNBC are now a subject of great interest due to the presence of tumor-infiltrating lymphocytes (TILs) in these tumors. This characteristic often coincides with the presence of PD-L1 expression on both neoplastic cells and immune cells within the tumor microenvironment. Furthermore, a subset of TNBC harbor mismatch repair deficient (dMMR) TNBC, which is frequently accompanied by microsatellite instability (MSI). All of these immune biomarkers hold actionable potential for guiding patient selection in immunotherapy. To fully capitalize on these opportunities, the identification of additional or complementary biomarkers and the implementation of highly customized testing strategies are of paramount importance in TNBC. In this regard, this article aims to provide an overview of the current state of the art in immune-related biomarkers for TNBC. Specifically, it focuses on the various testing methodologies available and sheds light on the immediate future perspectives for patient selection. By delving into the advancements made in understanding the immune landscape of TNBC, this study aims to contribute to the growing body of knowledge in the field. The ultimate goal is to pave the way for the development of more personalized testing strategies, ultimately improving outcomes for TNBC patients.

The molecular landscape of breast mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) of the breast is an extremely rare salivary gland-type tumor characterized by epidermoid, basaloid, intermediate, and/or mucinous cells arranged in solid and cystic patterns. Despite their triple-negative phenotype, breast MECs are generally considered low-risk malignancies but their biology is largely unexplored; therefore, guidelines for clinical management are lacking. Here, we sought to characterize the molecular landscape of breast MECs. Thirteen cases were histologically reviewed, characterized for tumor-infiltrating lymphocytes (TILs), and were subjected to immunohistochemistry for programmed death-ligand 1 (PD-L1, clone 22C3), EGFR, and amphiregulin (AREG). Rearrangements in MAML2 and EWSR1 were investigated by fluorescent in situ hybridization. Targeted next-generation sequencing of 161 genes was performed on eight cases. Most MECs had low histological grade (n = 10, 77%), with the presence of TILs (n = 9/12; 75%) and PD-L1 combined positive score ranging from 10 to 20 (n = 4/6; 67%). All cases showed EGFR and AREG overexpression and were fusion negative. Enrichment of genetic alterations was observed in PI3K/AKT/mTOR and cell cycle regulation pathways, while only one case harbored TP53 mutations. This is the first study providing extensive molecular data on breast MECs and the largest collection of cases available to date in the literature. Breast MECs lack TP53 mutations found in high-grade forms of triple-negative breast cancers and MAML2 or EWSR1 rearrangements pathognomonic of salivary MECs. Triple-negativity and PD-L1 positivity suggest a window of opportunity for immunotherapy in these patients. The EGFR/AREG axis activation, coupled with the mutational patterns in PI3K/AKT/mTOR and cell cycle pathways warrants caution in considering MECs as low-risk neoplasms.

Transcytosable Peptide-Paclitaxel Prodrug Nanoparticle for Targeted Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an extremely aggressive subtype associated with a poor prognosis. At present, the treatment for TNBC mainly relies on surgery and traditional chemotherapy. As a key component in the standard treatment of TNBC, paclitaxel (PTX) effectively inhibits the growth and proliferation of tumor cells. However, the application of PTX in clinical treatment is limited due to its inherent hydrophobicity, weak penetrability, nonspecific accumulation, and side effects. To counter these problems, we constructed a novel PTX conjugate based on the peptide-drug conjugates (PDCs) strategy. In this PTX conjugate, a novel fused peptide TAR consisting of a tumor-targeting peptide, A7R, and a cell-penetrating peptide, TAT, is used to modify PTX. After modification, this conjugate is named PTX-SM-TAR, which is expected to improve the specificity and penetrability of PTX at the tumor site. Depending on hydrophilic TAR peptide and hydrophobic PTX, PTX-SM-TAR can self-assemble into nanoparticles and improve the water solubility of PTX. In terms of linkage, the acid- and esterase-sensitive ester bond was used as the linking bond, with which PTX-SM-TAR NPs could remain stable in the physiological environment, whereas PTX-SM-TAR NPs could be broken and PTX be released at the tumor site. A cell uptake assay showed that PTX-SM-TAR NPs were receptor-targeting and could mediate endocytosis by binding to NRP-1. The vascular barrier, transcellular migration, and tumor spheroids experiments showed that PTX-SM-TAR NPs exhibit great transvascular transport and tumor penetration ability. In vivo experiments, PTX-SM-TAR NPs showed higher antitumor effects than PTX. As a result, PTX-SM-TAR NPs may overcome the shortcomings of PTX and present a new transcytosable and targeted delivery system for PTX in TNBC treatment.

Efficacy and prognostic factors of neoadjuvant chemotherapy for triple-negative breast cancer

BACKGROUND

Breast cancer mainly occurs in young and premenopausal women; its incidence is increasing annually. Patients with triple-negative breast cancer (TNBC) have relatively high recurrence and transfer rates during the operation and 3 years after postoperative adjuvant chemotherapy. Currently, the treatment for patients with TNBC is mainly based on a comprehensive combination of surgery and chemotherapy. Therefore, identifying additional effective treatments to improve patient prognosis is important.

AIM

To explore and discuss the effects and prognostic factors of neoadjuvant chemotherapy in TNBC.

METHODS

In total, 118 patients diagnosed with TNBC from January 2016 to January 2020 in our hospital were selected and divided into the observation (n = 60) and control (n = 58) groups according to therapeutic regimen. The control group received routine chemotherapy, and the observation group received neoadjuvant chemotherapy. The therapeutic effects of the two groups were observed, and the survival of patients was followed up.

RESULTS

The karyopherin A2 (KPNA2)-positive and SRY-related HMG box-2 (SOX2)-positive expression rates of patients with TNBC with intravascular tumor thrombus and tumor-node-metastasis (TNM) stage IV were 92.00% and 91.67% and 96.00% and 95.83%, respectively, which were significantly higher than those of patients with no intravascular tumor thrombus and TNM stage III (P < 0.05). KPNA2 was positively associated with SOX2 expression (r_s = 0.514, P < 0.50). The short-term curative effect of the observation group was better than that of the control group (P < 0.05), and the total effective rate was 58.33%. After treatment, carcinoembryonic antigen, cancer antigen (CA) 19-9, and CA125 Levels in the observation group were 11.40 ± 2.32 mg/L, 19.92 ± 3.42 kU/L, and 54.30 ± 12.28 kU/L, respectively, which were significantly lower than those in the control group (P < 0.05). The median survival time of the observation group was 33 mo (95%CI: 31.21-34.79), which was significantly longer than that of the control group (P < 0.05). TNM stage, degree of differentiation, lymph node metastasis, KPNA2 and SOX2 expressions, and treatment plan were prognostic factors of TNBC (relative risk = 1.575, 1.380, 1.366, 1.433, 1.411, and 0.581, respectively, P < 0.05).

CONCLUSION

Neoadjuvant chemotherapy for TNBC treatment can achieve good curative effects. TNM stage, differentiation degree, lymph node metastasis, KPNA2 and SOX2 expressions, and treatment plan are prognostic factors of TNBC.

Chemical degrader enhances the treatment of androgen receptor-positive triple-negative breast cancer

Androgen receptor (AR) is a promising therapeutic target for AR-positive triple-negative breast cancer (TNBC). However, clinical trials of AR inhibitors only reveal modest therapeutic efficacy for AR-positive TNBC, and drug resistance is also inevitable. To address these challenges, we herein report the use of an AR-targeting proteolysis targeting chimera (AR-PROTAC) to treat AR-positive TNBC. We demonstrated that AR-PROTAC potently degraded AR protein via the ubiquitin-proteasome pathway in AR-positive TNBC BT549 cells, with a half degradation concentration of ∼46.9 nM. By evaluating the therapeutic efficacies in vitro and in vivo, we validated that AR-PROTAC was superior to enzalutamide, an AR inhibitor. Specifically, AR-PROTAC at 100 nM reduced BT549 cell viability by up to ∼80%, and AR-PRTOAC at 10 mg/kg suppressed tumor growth by ∼60% when administrated intratumorally in subcutaneous BT549 tumor mice model. Overall, these results demonstrate for the first time that PROTAC holds promise to enhance the treatment of AR-positive TNBC.

RNA-binding protein complex LIN28/MSI2 enhances cancer stem cell-like properties by modulating Hippo-YAP1 signaling and independently of Let-7

The RNA binding protein LIN28 directly modulates the stability and translation of target mRNAs independently of Let-7; however, the key downstream targets of LIN28 in this process are largely unknown. Here, we revealed that Hippo signaling effector YAP1 functioned as a key downstream regulator of LIN28 to modulate the cancer stem cell (CSC)-like properties and tumor progressions in triple negative breast cancer (TNBC). LIN28 was overexpressed in BC tissues and cell lines, and significantly correlated with poorer overall survivals in patients. Ectopic LIN28 expression enhanced, while knockdown of LIN28A inhibited the CSC-like properties, cell growth and invasive phenotypes of TNBC cells in vitro and in vivo. Transcriptome analysis demonstrated LIN28 overexpression significantly induced the expressions of YAP1 downstream genes, while reduced the transcripts of YAP1 upstream kinases, such as MST1/2 and LATS1/2, and knockdown of LIN28A exhibited the opposite effects. Furthermore, constitutive activation of YAP1 in LIN28 knockdown TNBC cells could rescue the cell growth and invasive phenotypes in vitro and in vivo. Mechanistically, instead of the dependence of Let-7, LIN28 recruited RNA binding protein MSI2 in a manner dependent on the LIN28 CSD domain and MSI2 RRM domain, to directly induce the mRNA decay of YAP1 upstream kinases, leading to the inhibition of Hippo pathway and activation of YAP1, which eventually gave rise to increased CSC populations, enhanced tumor cell growth and invasive phenotypes. Accordingly, co-upregulations of LIN28 and MSI2 in TNBC tissues were strongly associated with YAP1 protein level and tumor malignance. Taken together, our findings unravel a novel LIN28/MSI2-YAP1 regulatory axis to induce the CSC-like properties, tumor growth and metastasis, independently of Let-7, which may serve as a potential therapeutic strategy for the treatment of a subset of TNBC with LIN28 overexpression.

Efficacy and potential mechanisms of Chinese herbal compounds in coronavirus disease 2019: advances of laboratory and clinical studies

The Coronavirus disease 2019 (COVID-19) pandemic is still spread and has made a severe public health threat around the world. To improve disease progression, emerging Chinese herbal compounds were used in clinical practice and some agents have proven beneficial in treating COVID-19. Here, the relevant literature from basic researches to clinical application were identified and comprehensively assessed. A variety of Chinese herbal compounds have been reported to be effective in improving symptoms and outcomes in patients with COVID-19, particularly together with routine treatment strategy. The pharmacological activities were mainly attributed to the relief of clinical symptoms, inhibition of cytokine storm, and improvement of organ function. Besides, the development of novel antiviral drugs from medicinal herbs were further discussed. The updated laboratory and clinical studies provided the evidence of Chinese herbal compounds such as Lianhua Qingwen prescription, Shufeng Jiedu prescription, and Qingfei Paidu Tang for the relief of COVID-19. However, both of the randomized controlled trials and real world researches need to be done for supporting the evidence including the efficacy and safety in fighting COVID-19.

Oral vinorelbine and capecitabine as first-line therapy in metastatic breast cancer: a retrospective analysis

A retrospective analysis of 70 patients with triple-negative or hormone-resistant advanced breast carcinoma who had not previously received chemotherapy was carried out. Patients received oral vinorelbine 60 mg/m2 on day 1 and 8, plus capecitabine 1000 mg/m2 bid for 14 consecutive days every 3 weeks. Overall response rate was 53% with a 9% complete response rate. Stable disease was recorded in 27% of the cases. Median progression-free survival was 7.9 months and median overall survival was 29.2 months. Toxicity was generally mild and easily manageable. These data demonstrate that this combination is feasible, safe and active as first-line treatment of triple-negative fully hormone-resistant advanced breast carcinoma patients.

The Single-Cell Sequencing: A Dazzling Light Shining on the Dark Corner of Cancer

Tumorigenesis refers to the process of clonal dysplasia that occurs due to the collapse of normal growth regulation in cells caused by the action of various carcinogenic factors. These “successful” tumor cells pass on the genetic templates to their generations in evolutionary terms, but they also constantly adapt to ever-changing host environments. A unique peculiarity known as intratumor heterogeneity (ITH) is extensively involved in tumor development, metastasis, chemoresistance, and immune escape. An understanding of ITH is urgently required to identify the diversity and complexity of the tumor microenvironment (TME), but achieving this understanding has been a challenge. Single-cell sequencing (SCS) is a powerful tool that can gauge the distribution of genomic sequences in a single cell and the genetic variability among tumor cells, which can improve the understanding of ITH. SCS provides fundamental ideas about existing diversity in specific TMEs, thus improving cancer diagnosis and prognosis prediction, as well as improving the monitoring of therapeutic response. Herein, we will discuss advances in SCS and review SCS application in tumors based on current evidence.

Clinicopathological Characteristics and Prognosis of Squamous Cell Carcinoma of the Breast: A Population-Based Analysis

Background

To better understand the clinicopathological features and prognostic profiles of squamous cell carcinoma (SCC) of the breast.

Methods

Information on breast cancer was obtained from the Surveillance, Epidemiology, and End Results database (2004–2016). Comparative analyses were carried out to investigate the heterogeneity in the clinicopathological characteristics and survival outcomes between SCC and invasive ductal carcinoma (IDC), while propensity score matching was conducted to analyze the variations among baseline characteristics. Prognostic factors for SCC of the breast were successively identified using Cox regression analysis.

Results

A total of 382 SCC patients and 561477 IDC patients were identified in this study. Comparatively, the SCC cohort exhibited a higher proportion of male individuals, poor differentiation, an advanced TNM stage, an increasing percentage of triple-negative (TN) subtype, an increasing rate of organ involvement, and less access to therapeutics. The aggressive profile was consistent in the TN subgroup, with a significantly higher proportion in SCC than in IDC (25.7% vs 6.8%). Prognosis of SCC was profoundly poorer than that of IDC (mOS, 78.6 months and 121.6 months, P < .0001; mBCSS 91.9 months vs 135.6 months, P < .0001), of which the inferior tendency remained stable among disease stage and therapeutic options, while no difference was detected in the 2 subgroups with the TN subtype. The 2-year survival rate was 66.9% and the 5-year survival rate was 51.4%, with the risk factors being older age, bilateral disease, advanced TNM stage, bone and visceral involvement, surgical intervention, radiation treatment, and chemotherapy.

Conclusions

This study systematically analyzed the heterogeneous characteristics of SCC of the breast in comparison with IDC. Squamous cell breast cancer presented with increasing aggressive behavior and inferior prognosis. Prospective studies should focus on this subgroup and introduce individualized therapeutic protocols in clinical practice.