Premenopausal Breast Cancer

PCBP1-mediated regulation of WNT signaling is critical for breast tumorigenesis

Loss of expression or protein kinase B (Akt1)-mediated post-translational modification of the RNA binding protein Poly r(C) binding protein 1 (PCBP1) is closely related to metastatic advancement of breast cancer. However, the role of PCBP1 in tumorigenesis is not completely defined. Using a xenograft orthotopic model of breast tumorigenesis (4T1-Pcbp1-/-), we show here that PCBP1 knockdown-induced tumorigenesis is inhibited by activation of the WNT signaling via treating with the glycogen synthase kinase 3 beta inhibitor TWS119, but not the Akt2/Akt3 inhibitor GSK690693. Mass cytometry-based evaluation of the tumor microenvironment (TME) revealed significantly more regulatory T cells (Tregs) and significantly less cytotoxic T cells in 4T1-Pcbp1-/-mice treated with saline control in comparison to mice treated with TWS119. Infiltrating cytotoxic T cells were phenotypically and functionally exhausted. Treatment with TWS119 resulted in rescue of cytotoxic T cell function and inhibition of suppressor activity of Tregs. Using cytotoxic T cells isolated from healthy donors, we show that TWS119-induced WNT signaling-mediated inhibition of cytotoxic T cell expansion is reliant on expression of PCBP1. In conclusion, decreased PCBP1 expression favors breast tumorigenesis by potentiating skewing of tumor infiltrating T cells towards Tregs, thereby effectively suppressing anti-tumor immunity.

Treatment with eFT-508 increases chemosensitivity in breast cancer cells by modulating the tumor microenvironment

Background

Patients with triple-negative breast cancer (TNBC) are better responders to neoadjuvant chemotherapy; however, they are poor in the durability of response with decreased overall and progression-free survival.

Methods

Given that significant improvements have been reported with PD-L1-PD-1 blockade in different cancers, we evaluated the in vitro and in vivo effectiveness of Tomivosertib (eFT-508), an anthracycline, adriamycin, and MNK1/2 inhibitor, which has been previously shown to inhibit translation of PD-L1 in mice model of liver cancer, alone or in combination using BC cell lines and an orthotopic xenograft mice model using the TNBC cell line MDA-MB-231.

Results

Within the context of The Cancer Genome Atlas (TCGA) dataset, expression of CD274 mRNA, which encodes programmed death-ligand 1 (PD-L1), was found to be significantly overexpressed in TNBC patients compared to patients with HER2 + or luminal breast cancer (BC). Even within TNBC sub-types, CD274 expression was significantly higher in the immune modulatory subtype (TNBC-IM).

BC cells exhibited high IC₅₀ = 0.85 ± 0.07 nM with Adriamycin and significantly lower IC₅₀ = 0.23 ± 0.04 nM with eFT-508 (P < 0.01). Combination treatment showed in vitro synergism on chemosensitivity. Combination therapy also exhibited a synergistic effect on inhibition of tumor growth and lung colonization in vivo. Mass cytometry-based evaluation of the tumor microenvironment revealed significant attenuation of both PD-L1 and PD-L2 following mono- or combination therapy with eFT-508.

Conclusions

Treatment with eFT-508 restored effector and cytotoxic function of tumor-infiltrating CD8 + T cells in mice. The remarkable efficacy observed both in vitro and in vivo, and clinical synergism with adriamycin, highlights the potential of eFT-508 as an alternative, yet more efficacious, therapeutic option for patients with TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03474-9.

miRNA‑490‑3p promotes the metastatic progression of invasive ductal carcinoma

MicroRNA (miRNA/mir)‑490‑3p has been defined as a tumor suppressor in different types of cancer, including breast cancer. However, miR‑490‑3p has been shown to function as a tumor suppressor and promoter in a context‑dependent manner in hepatocellular and lung cancer. Contrary to previous studies, the present study revealed that miR‑490‑3p expression was significantly higher in invasive ductal carcinoma (IDC) tissue specimens, the most common form of breast cancer, compared to tumor‑adjacent normal tissue specimens (n=20). Its expression was also higher in the more metastatic breast cancer cell line, MDA‑MB‑231, compared to the non‑metastatic breast cancer cell line, MCF7, and the moderately metastatic breast cancer cell line, MDA‑MB‑468. The expression of miR‑490‑3p was induced following transforming growth factor (TGF)‑β‑induced epithelial‑to‑mesenchymal transition (EMT) in MCF10A cells. Gain‑and loss‑of‑function assays revealed that the expression of miR‑490‑3p regulated the proliferation, colony formation, EMT, migration and invasion in vitro, but not the apoptosis of MDA‑MB‑468 and MDA‑MB‑231 cells. The knockdown of miR‑490‑3p expression in MDA‑MB‑231 cells inhibited experimental metastasis in a tumor xenograft assay. As in lung cancer, miR‑490‑3p was found to target and downregulate the expression of the tumor suppressor RNA binding protein poly r(C) binding protein 1 (PCBP1). PCBP1 protein and miR‑490‑3p expression inversely correlated in patients with ductal carcinoma in situ (DCIS; n=10; no nodal involvement) and IDC (n=10; different stages of metastatic progression) with a significantly higher miR‑490‑3p expression in patients with IDC compared to those with DCIS. The expression of miR‑490‑3p was negatively associated with both overall and disease‑free survival in the patients with breast cancer included in the present study. On the whole, the results confirm a pro‑metastatic role of miR‑490‑3p in IDC, establishing it as a biomarker for disease progression in these patients.

Insulin-Induced Gene 2 Expression Is Associated with Breast Cancer Metastasis

Insulin-induced gene 2 (INSIG2) functions as a blocker of cholesterol biosynthesis and has been shown to be involved in colon and pancreatic cancer pathogenesis. Cholesterol is a risk factor for breast cancer pathophysiology; however, the underlying mechanisms are not well-defined. Hence, our goal was to determine the role of INISG2 in breast cancer. INSIG2 mRNA and protein expression was correlated to metastatic potential of breast cancer cell lines. Knockdown of INSIG2 inhibited epithelial-to-mesenchymal transition. Conversely, overexpression of INSIG2 induced epithelial-to-mesenchymal transition. Knockdown of INSIG2 did not affect cell proliferation but resulted in altered metabolism in vitro and attenuated experimental metastasis in vivo. Analysis of breast cancer tissue microarrays revealed significantly higher INSIG2 protein expression in breast cancer tissues. INSIG2 protein expression was correlated to hormone receptor status, with significantly higher expression in patients with triple-negative and human epidermal growth factor receptor 2 molecular subtypes of invasive breast cancer. Analysis of The Cancer Genome Atlas, however, revealed significantly lower INSIG2 mRNA expression in triple-negative breast cancer patients. Higher INSIG2 mRNA expression was correlated to poor survival probability. Asian patients with high INSIG2 mRNA expression had significantly lower survival probability compared with Asian patients with low/medium INSIG2 mRNA expression. These results reveal a yet undefined role of INSIG2 in breast cancer, potentially more relevant for breast cancer patients in Asia.

The effects of apoptosis and apelin on lymph node metastasis in invasive breast carcinomas

This study aimed to evaluate the biological and clinical significance of apelin-36 in breast cancer and to compare apelin-36 expression and apoptotic index in both breast tissue and metastatic lymph nodes in patients with invasive breast carcinoma. In this study, both tumor tissue and metastatic lymph nodes of the same patient were collected from 60 cases of invasive breast carcinoma patients (IDC, ILC) and 20 cases of normal breast tissue with no tumor from mammoplasty were used as the control group. The expression of apelin was examined with immunohistochemically, and the apoptotic index was examined with TUNEL methods. According to Kruskal-Wallis analysis, there was a significant difference between IDC and the control group when the apelin expression was compared between the breast tissues (p = 0.001). There were significant differences between the three groups when comparing relationships with apoptotic index (p < 0.001). According to the Mann-Whitney U test, both tumor size and expression of apelin in lymph nodes in ILCs were significantly higher than IDCs. (p = 0.026, p = 0.024, respectively). According to correlation analysis, there was a good correlation between the expression of apelin in breast tissue and apelin expression in lymph nodes (p = 0.000). It is also found a similar relationship in terms of the apoptotic index (p = 0.000). In addition, the negative correlation was found between apelin expression and the apoptotic index in breast tissues (p = 0.003). Based on these results, apelin-36 can be used as a marker for determining the metastasis potential in invasive breast cancer.

Association of CA 15-3 and CEA with clinicopathological parameters in patients with metastatic breast cancer

The objective of this study was to investigate the association of serum cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) levels with clinicopathological parameters in patients diagnosed with metastatic breast cancer (MBC). We retrospectively evaluated the medical records of 284 patients diagnosed with MBC between January, 2007 and December, 2012 who fulfilled the specified criteria and the association between the levels of the two tumor marker and clinicopathological parameters was analyzed. Of the 284 patients, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were identified in 163 (57.4%) and 97 (34.2%) patients, respectively. Elevated CA 15-3 and CEA levels were significantly associated with breast cancer molecular subtypes (P<0.001 and P=0.032, respectively). Cases with luminal subtypes exhibited a higher percentage of elevated CA 15-3 and CEA levels compared to non-luminal subtypes. Elevated CA 15-3 level was correlated with bone metastasis (P=0.017). However, elevation of CEA was observed regardless of the site of metastasis. Elevation of CA 15-3 was significantly more common in MBC with multiple metastatic sites compared to MBC with a single metastasis (P=0.001). However, the incidence of elevated CEA levels did not differ between patients with a single and those with multiple metastatic sites. In conclusion, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were found to be associated with breast cancer molecular subtypes, whereas an elevated CA 15-3 level was significantly correlated with bone metastasis and an elevated CEA level was observed regardless of metastatic site. The proportion of MBC cases with elevated CA 15-3 levels differed according to the number of metastatic sites.

Prognostic value of Ki-67 in breast cancer patients with positive axillary lymph nodes: a retrospective cohort study

Introduction

Ki-67 expression is a biomarker for proliferation. Its prognostic value is recognized in breast cancer (BC) patients with negative axillary nodes, but is less clear in BC patients with positive axillary lymph nodes.

Methods

We retrospectively reviewed the medical records of 1131 Chinese BC patients treated from January 2002 to June 2007 and 450 patients met the inclusion criteria: positive nodes, adjuvant therapy, and complete biomarker profile (estrogen receptor (ER), progesterone receptor (PR), HER2, p53, Ki-67). Univariate and multivariate regression analysis were used to correlate biomarkers and tumor characteristics with metastasis free survival (MFS) and overall survival (OS).

Results

Median follow-up time was 46 months (range 5–76 months). The Ki-67 expression was associated significantly with histological grade, ER, PR, HER2, and P53 status (P<0.05). Tumor stage, nodal stage, and ER status were independent prognostic factors for MFS. Ki-67 status was associated significantly with OS but not MFS. To determine whether the extent of LN involvement in the BC patients influenced the role of Ki-67 in survival rates, we compared these variables in patients with 1–3 positive lymph nodes (N1) to those of patients with ≥4 positive lymph nodes. Ki-67 status was an independent prognostic factor for MFS (Hazard Ratio, 3.27, P = 0.026) and overall survival (HR, 10.64, P = 0.007) in patients with 1–3 positive nodes (N1).

Conclusions

The possibility that Ki-67 expression together with clinical factors can improve prediction of the prognosis of BC patients with 1∼3 positive axillary lymph nodes warrants further studies.

Biological characteristics of breast cancer at the primary tumour and the involved lymph nodes

Diminished oestrogen receptor (ER) expression in the involved axillary lymph nodes (ALN) in breast cancer compared with the primary tumour has been reported in previous studies. We have assessed a wider spectrum of tumour markers (ER, progesterone receptor (PgR), p53, Ki-67 and HER-2/neu) and compared extent and staining intensities at the primary tumour and the involved ALN on specimens of 22 cases with invasive ductal breast cancer. At the involved ALN, both the quantity of positive staining cells and the staining intensities for ER and PgR were decreased (p < 0.001 and p = 0.003, respectively). In contrast, the quantity of positive staining cells (p < 0.004) and the staining intensities for Ki-67 were increased. The differences for HER-2/neu and p53 staining at both sites were insignificant. The immunohistochemical staining properties of both the primary tumour and the ALN metastases showed no correlation with the number of involved ALN (p > 0.05). This study suggested that ALN metastasis might indicate a more unfavourable expression pattern of ER, PgR and Ki-67 in invasive ductal breast cancer.