BRCA1 and Metastasis: Outcome of Defective DNA Repair

The effect of human umbilical cord mesenchymal stem cells conditioned medium combined with tamoxifen drug on BRCA1 and BRCA2 expression in breast cancer mouse models

BACKGROUND

A growing number of studies has indicated that the expression of Breast Cancer Susceptibility Genes 1 (BRCA1) and BRCA2 contribute to the resistance to DNA-damaging chemotherapies. Tamoxifen induces tumor cell death by suppressing estrogen receptor (ER) signaling and inducing DNA damage, and BRCA1 upregulation causes Tamoxifen chemoresistance in breast cancer cells. Consequently, this research study aimed to investigate the possible therapeutic effect of Human Umbilical Cord Mesenchymal Stem Cells Conditioned Medium (UCMSCs-CM) on sensitizing breast cancer cells to Tamoxifen by regulating BRCA1 and BRCA2 expression in vivo.

METHODS

Forty female mice, 4-8 weeks old, with weight of 150 g, were used for this study. Mouse 4T1 breast tumor models were established and then treated with UCMSCs-CM and Tamoxifen alone or in combination. After 10 days, the tumor masses were collected and the expression levels of BRCA1 and BRCA2 were evaluated using qRT-PCR assay.

RESULTS

The results obtained from qRT-PCR assay illustrated that UCMSCs-CM, either alone or in combination with Tamoxifen, significantly downregulated the mRNA expression levels of BRCA1 in breast cancer mouse models. However, both UCMSCs-CM and Tamoxifen indicated no statistically significant impact on BRCA2 mRNA expression compared to controls.

CONCLUSION

Our findings evidenced that UCMSCs-CM could be considered as a potential therapeutic option to modulate Tamoxifen chemosensitivity by regulating BRCA1 in breast cancer.

BRCA1 mutation promotes sprouting angiogenesis in inflammatory cancer-associated fibroblast of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with inferior outcomes owing to its low treatment response and high invasiveness. Based on abundant cancer-associated fibroblasts (CAFs) and frequent mutation of breast cancer-associated 1 (BRCA1) in TNBC, the characteristics of CAFs in TNBC patients with BRCA1 mutation compared to wild-type were investigated using single-cell analysis. Intriguingly, we observed that characteristics of inflammatory CAFs (iCAFs) were enriched in patients with BRCA1 mutation compared to the wild-type. iCAFs in patients with BRCA1 mutation exhibited outgoing signals to endothelial cells (ECs) clusters, including chemokine (C-X-C motif) ligand (CXCL) and vascular endothelial growth factor (VEGF). During CXCL signaling, the atypical chemokine receptor 1 (ACKR1) mainly interacts with CXCL family members in tumor endothelial cells (TECs). ACKR1-high TECs also showed high expression levels of angiogenesis-related genes, such as ANGPT2, MMP1, and SELE, which might lead to EC migration. Furthermore, iCAFs showed VEGF signals for FLT1 and KDR in TECs, which showed high co-expression with tip cell marker genes, including ZEB1 and MAFF, involved in sprouting angiogenesis. Moreover, BRCA1 mutation patients with relatively abundant iCAFs and tip cell gene expression exhibited a limited response to neoadjuvant chemotherapy, including cisplatin and bevacizumab. Importantly, our study observed the intricate link between iCAFs-mediated angiogenesis and chemoresistance in TNBC with BRCA1 mutation.

Thinking (Metastasis) outside the (Primary Tumor) Box

The metastasis of tumor cells into vital organs is a major cause of death from diverse types of malignancies [...].

Whole Exome Sequencing reveals clinically important pathogenic mutations in DNA repair genes across lung cancer patients

Lung cancer remains a substantial health challenge, with distinct genetic factors influencing disease susceptibility and progression. This study aimed to decipher the landscape of DNA repair gene mutations in Pakistani lung cancer patients using Whole Exome Sequencing (WES) and to investigate their potential functional implications through downstream analyses. WES analysis of genomic DNA from 15 lung cancer patients identified clinically important pathogenic mutations in 6 DNA repair genes, including, BReast CAncer gene 1 (BRCA1), BReast CAncer gene 2 (BRCA2), Excision Repair Cross Complementing rodent repair deficiency, complementation group 6 (ERCC6), Checkpoint Kinase 1 (CHEK1), mutY DNA glycosylase (MUTYH), and RAD51D (RAD51 Paralog D). Kaplan-Meier (KM) analysis showed that pathogenic mutations in BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D genes were the prognostic biomarkers of worse OS in lung cancer patients. To explore the functional impact of these mutations, we performed Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Immunohistochemistry (IHC) analyses. Our results revealed a down-regulation in the expression of the mutated genes, indicating a potential link between the identified mutations and reduced gene activity. This down-regulation could contribute to compromised DNA repair efficiency, thereby fostering genomic instability in lung cancer cells. Furthermore, targeted bisulfite sequencing analysis was employed to assess the DNA methylation status of the mutated genes. Strikingly, hypermethylation in the promoters of BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D was observed across lung cancer samples harboring pathogenic mutations, suggesting the involvement of epigenetic mechanism underlying the altered gene expression. In conclusion, this study provides insights into the genetic landscape of DNA repair gene mutations in Pakistani lung cancer patients. The observed pathogenic mutations in BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D, coupled with their down-regulation and hypermethylation, suggest a potential convergence of genetic and epigenetic factors driving genomic instability in lung cancer cells. These findings contribute to our understanding of lung cancer susceptibility and highlight potential avenues for targeted therapeutic interventions in Pakistani lung cancer patients.

Cancer invasion and metastasis: Insights from murine pubertal mammary gland morphogenesis

Cancer invasion and metastasis accounts for the majority of cancer related mortality. A better understanding of the players that drive the aberrant invasion and migration of tumors cells will provide critical targets to inhibit metastasis. Postnatal pubertal mammary gland morphogenesis is characterized by highly proliferative, invasive, and migratory normal epithelial cells. Identifying the molecular regulators of pubertal gland development is a promising strategy since tumorigenesis and metastasis is postulated to be a consequence of aberrant reactivation of developmental stages. In this review, we summarize the pubertal morphogenesis regulators that are involved in cancer metastasis and revisit pubertal mammary gland transcriptome profiling to uncover both known and unknown metastasis genes. Our updated list of pubertal morphogenesis regulators shows that most are implicated in invasion and metastasis. This review highlights molecular linkages between development and metastasis and provides a guide for exploring novel metastatic drivers.

ZFP57 promotes ovarian cancer progression by transcriptionally regulating BRCA1 and managing G1 checkpoint

Ovarian cancer (OC) which is one of the frequently-occurring gynecologic malignant tumors, endangers the health of women. The zinc finger protein 57 (ZFP57) plays crucial functions during the progression of cancer and is reported as a prognostic and therapeutic candidate in a variety of cancer. However, the biological function as well as the underlying mechanism of ZFP57 during OC progression remains unknown. Here, ZFP57 expression was found prominently increased in OC tissues and correlated with the prognosis of OC patients. Knock down of ZFP57 in OC cells inhibited the cell proliferation and migration, and also arrested the cells at G1 phase as well as accelerated the apoptosis. Additionally, ZFP57 transcriptionally regulated BRCA1 expression in OC, indicating that ZFP57 may affect BRCA1 mediated G1 checkpoint to regulate the cell cycle of OC cells and further influence the progression of OC. Taken together, our present study discovered a novel function of ZFP57 in OC, suggesting that ZFP57 could be potentially treated as a prognostic biomarker and therapeutic target for OC patients.

Global trends in BRCA-related breast cancer research from 2013 to 2022: A scientometric analysis

Introduction

Since the mid-2000s, breast cancer incidence among women has slowly increased at about 0.5% per year. In the last three decades, Breast Cancer Susceptibility Gene (BRCA) has been proven to be the crucial gene in encouraging the incidence and development of breast cancer. However, scientometric analysis on BRCA-related breast cancer is in shortage. Thus, to have a clear understanding of the current status and catch up with the hotspots, a scientometric analysis was conducted on specific academic publications collected from the Web of Science (WoS).

Methods

We searched the Web of Science Core Collection (WoSCC) to procure associated articles as our dataset. Bibliometric, CiteSpace, VOSviewer, and HistCite software were then applied to conduct visual analyses of countries, institutions, journals, authors, landmark articles, and keywords in this research field.

Results

A total of 7,266 articles and 1,310 review articles published between 2013 to 2022 were retrieved eventually. The annual output steadily rose year by year and peaked in 2021. The USA led the way in the number of published works, total citations, and collaboration. Breast Cancer Research and Treatment was the most favoured journal in this research field. Narod SA from the University of Toronto produced the most publications. At last, the most prominent keywords were "breast cancer" (n=1,778), "women" (n=1,369), "brca1" (n=1,276), "ovarian cancer" (n=1,259), "risk" (n=1,181), and "mutations" (n=929), which exposed the hotspots within the BRCA domain of breast cancer study.

Conclusion

The tendency in the BRCA research field over the past decade was presented by the scientometric analysis. The current research focus is the clinical trials of poly-adenosine diphosphate ribose polymerase inhibitors (PARPi) drugs and their resistance mechanisms.

Targeting the stimulator of interferon genes (STING) in breast cancer

Breast cancer has a high occurrence rate globally and its treatment has demonstrated clinical efficacy with the use of systemic chemotherapy and immune checkpoint blockade. Insufficient cytotoxic T lymphocyte infiltration and the accumulation of immunosuppressive cells within tumours are the primary factors responsible for the inadequate clinical effectiveness of breast cancer treatment. The stimulator of interferon genes (STING) represents a pivotal protein in the innate immune response. Upon activation, STING triggers the activation and enhancement of innate and adaptive immune functions, resulting in therapeutic benefits for malignant tumours. The STING signalling pathway in breast cancer is influenced by various factors such as deoxyribonucleic acid damage response, tumour immune microenvironment, and mitochondrial function. The use of STING agonists is gaining momentum in breast cancer research. This review provides a comprehensive overview of the cyclic guanosine monophosphate-adenosine monophosphate synthase-STING pathway, its agonists, and the latest findings related to their application in breast cancer.

METTL3 suppresses anlotinib sensitivity by regulating m6A modification of FGFR3 in oral squamous cell carcinoma

Background

N6-methyladenosine (m⁶A) is an abundant nucleotide modification in mRNA, but there were few studies on its role in cancer drug sensitivity and resistance. Anlotinib has been proved to have effective antitumor effects in oral squamous cell carcinoma (OSCC) in our previous study. Here, we sought to investigate the treatment target of anlotinib and the function and mechanisms of m⁶A modification in regulating anlotinib effect in OSCC.

Methods

Anlotinib treatment in a dose-dependent manner, western blotting, qRT-PCR and cell lost-of-function assays were used to study the treatment target of anlotinib in OSCC. RNA m⁶A dot blot assays, the m⁶A MeRIP-seq and MeRIP-qPCR, RNA and protein stability assays were used to explore the m⁶A modification of the treatment target of anlotinib. Cell lost-of-function assays after METTL3 depletion were conducted to investigate the effect of m⁶A modification level on the therapeutic effect of anlotinib in OSCC. Patient-derived tumor xenograft (PDX) models and immunohistochemistry staining were performed to study the relationship of METTL3 and antitumor sensitivity of anlotinib in vivo.

Results

Anlotinib targeted FGFR3 in the treatment of OSCC and inhibited tumor cell proliferation and promoted apoptosis by inactivating the FGFR3/AKT/mTOR signaling pathway. METTL3 was identified to target and modify FGFR3 m⁶A methylation and then decrease the stability of mRNA. METTL3 expression level was related to the anlotinib sensitivity in OSCC cells in vitro and METTL3 knockdown promoted anlotinib sensitivity of OSCC cells by inhibiting the FGFR3 expression. PDX models samples furthermore showed that METTL3 and FGFR3 levels were tightly correlated with the anlotinib efficacy in OSCC.

Conclusions

In summary, our work revealed that FGFR3 was served as the treatment target of anlotinib and METTL3-mediated FGFR3 m⁶A modification played a critical function in the anlotinib sensitivity in OSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02715-7.

The mortalities of female-specific cancers in China and other countries with distinct socioeconomic statuses: A longitudinal study

INTRODUCTION

Female-specific cancers seriously affect physical and psychological health of women worldwide.

OBJECTIVES

We aimed to elucidate trends in the age-standardized mortality rates (ASMRs) of breast cancer, cervical cancer, uterine cancer, and ovarian cancer in female populations with different socioeconomic statuses in China and in countries with different Human Development Index (HDI).

METHODS

A longitudinal study was performed using the data of cancer death in China and other 39 countries. The mortality rates were standardized with the Segi's world population. Trends in the mortalities were exhibited by estimated annual percentage change (EAPC). Pearson correlation was used to assess the association between EAPC and HDI.

RESULTS

In mainland China, female breast cancer, cervical cancer, uterine cancer, and ovarian cancer accounted for 6.60 %, 4.21 %, 2.50 %, and 2.02 % of cancer death (n = 1,314,040) in women with 1,220,251,032 person-years, respectively. The ASMRs of cervical cancer (EAPC = 3.87 %, P < 0.001) and ovarian cancer (EAPC = 1.81 %, P < 0.001) increased, that of female breast cancer unchanged, whereas that of uterine cancer was extremely higher and rapidly decreased (EAPC =  - 7.65 %, P < 0.001), during 2004-2019. The ASMRs of female breast and ovarian cancers were higher in urban and developed regions than in rural and undeveloped regions, in contrast to cervical and uterine cancers. The ASMRs of female breast and ovarian cancers were lower in China than in other countries, in contrast to uterine cancer. The ASMR of cervical cancer decreased, that of uterine cancer increased, in other countries during 2004-2017. EAPCs for the ASMRs of breast and ovarian cancers were inversely correlated to HDI.

CONCLUSION

The ASMRs of cervical and ovarian cancers increased, in contrast to uterine cancer, in China during socioeconomic transition. Trends in the ASMRs of breast and ovarian cancers were inversely associated with HDI. These data help control female-specific cancers.

PARP-1 Expression and BRCA1 Mutations in Breast Cancer Patients' CTCs

Simple Summary

Recent estimates have shown that approx. 70% of individuals with BRCA1 mutations will develop breast cancer by the age of 70. To make matters worse, breast cancer patients with BRCA1 mutations are more likely to have the more aggressive triple-negative breast cancer. PARPs, belong to a family of nuclear enzymes, which are involved in many cellular processes, including DNA repair. PARP inhibitors have been approved for the treatment of BRCA-mutated breast cancer. The aim of the study was the determination of PARP-1 expression in the context of the presence of BRCA1 mutations in circulating tumor cells of breast cancer patients. PARP-1 (nuclear) expression and BRCA1 mutations were mainly detected in triple negative breast cancer patients, and the latter were correlated with decreased survival. Our data suggest that PARP-1, in conjunction with BRCA1, could potentially be used as (a) biomarker(s) for patients’ stratification.

Abstract

BRCA1 and PARP are involved in DNA damage repair pathways. BRCA1 mutations have been linked to higher likelihood of triple negative breast cancer (TNBC). The aim of the study was to determine PARP-1 expression and BRCA1 mutations in circulating tumor cells (CTCs) of BC patients. Fifty patients were enrolled: 23 luminal and 27 TNBC. PARP expression in CTCs was identified by immunofluorescence. Genotyping was performed by PCR-Sanger sequencing in the same samples. PARP-1 expression was higher in luminal (61%) and early BC (54%), compared to TNBC (41%) and metastatic (33%) patients. In addition, PARP-1 distribution was mostly cytoplasmic in luminal patients (p = 0.024), whereas it was mostly nuclear in TNBC patients. In cytokeratin (CK)-positive patients, those with the CK⁺PARP⁺ phenotype had longer overall survival (OS, log-rank p = 0.046). Overall, nine mutations were detected; M1 and M2 were completely new and M4, M7 and M8 were characterized as pathogenic. M7 and M8 were predominantly found in metastatic TNBC patients (p = 0.014 and p = 0.002). Thus, PARP-1 expression and increased mutagenic burden in TNBC patients’ CTCs, could be used as an indicator to stratify patients regarding therapeutic approaches.