Caveolin-1 expression as a prognostic marker in triple negative breast cancers of Asian women

Targeting the NF-κB p65/Bcl-2 signaling pathway in hepatic cellular carcinoma using radiation assisted synthesis of zinc nanoparticles coated with naturally isolated gallic acid

PURPOSE

Oral diethylnitrosamine (DEN) is a known hepatocarcinogen that damages the liver and causes cancer. DEN damages the liver through reactive oxygen species-mediated inflammation and biological process regulation.

MATERIALS AND METHODS

Gallic acid-coated zinc oxide nanoparticles (Zn-GANPs) were made from zinc oxide (ZnO) synthesized by irradiation dose of 50 kGy utilizing a Co-60 γ-ray source chamber with a dose rate of 0.83 kGy/h and gallic acid from pomegranate peel. UV-visible (UV) spectrophotometry verified Zn-GANP synthesis. TEM, DLS, and FTIR were utilized to investigate ZnO-NPs' characteristics. Rats were orally exposed to DEN for 8 weeks at 20 mg/kg five times per week, followed by intraperitoneal injection of Zn-GANPs at 20 mg/kg for 5 weeks. Using oxidative stress, anti-inflammatory, liver function, histologic, apoptotic, and cell cycle parameters for evaluating Zn-GANPs treatment.

RESULTS

DEN exposure elevated inflammatory markers (AFP and NF-κB p65), transaminases (AST, ALT), γ-GT, globulin, and total bilirubin, with reduced protein and albumin levels. It also increased MDA levels, oxidative liver cell damage, and Bcl-2, while decreasing caspase-3 and antioxidants like GSH, and CAT. Zn-GANPs significantly mitigated these effects and lowered lipid peroxidation, AST, ALT, and γ-GT levels, significantly increased CAT and GSH levels (p<0.05). Zn-GANPs caused S and G2/M cell cycle arrest and G0/G1 apoptosis. These results were associated with higher caspase-3 levels and lower Bcl-2 and TGF-β1 levels. Zn-GANPs enhance and restore the histology and ultrastructure of the liver in DEN-induced rats.

CONCLUSION

The data imply that Zn-GANPs may prevent and treat DEN-induced liver damage and carcinogenesis.

Metabolic coupling in phyllodes tumor of the breast and its association with tumor progression

There are markers of metabolic coupling in breast cancer. Loss of caveolin-1 (Cav-1) and upregulation of monocarboxylate transporters (MCTs), especially MCT1 and MCT4, serve an important role in metabolic coupling necessary for release and uptake of metabolites. However, the occurrence of these phenomena in phyllodes tumors (PTs) of the breast is unclear. A total of 101 PTs (60 benign, 26 borderline and 15 malignant) and nine breast tissue samples with no pathological lesions were analyzed. Immunohistochemical staining for Cav-1, MCT1 and MCT4 was performed using tissue microarray and their expression in both stromal and epithelial components was assessed. Cav-1 expression in PTs demonstrated a significant decrease in the stromal component compared with that in the normal breast tissues (P<0.001). MCT1 expression in both epithelial and stromal components was significantly increased in PTs, compared with that in normal breast tissues (both P<0.001). Stromal MCT1 and MCT4 expression were different depending on tumor grade of PTs, and stromal MCT1 expression significantly increased with increasing tumor grade (P<0.001). Although not statistically significant, stromal Cav-1 expression notably decreased with increases in PT grade. High stromal MCT1 expression was significantly associated with lower disease-free survival rate in comparison with low stromal MCT1 expression (P<0.05). These results suggested that changes in protein expression of Cav-1, MCT1 and MCT4 may be associated with tumorigenesis and progression of PTs of the breast.

Albumin Nanoparticles Surface Decorated with a Tumor-Homing Peptide Help in Selective Killing of Triple-Negative Breast Cancer Cells

In this article, we describe a method of delivery of doxorubicin using a novel tumor-homing peptide-based albumin nanoparticle system to triple-negative breast cancer cells (TNBC). The absence and reduced expression of the hormone (estrogen, progesterone) and HER2 (human epidermal growth factor 2) receptors, respectively, render TNBC patients nonsusceptible to different available targeted therapies. These peptide-modified nanoparticles could be taken up by TNBC cells more effectively than their bare counterparts. The drug-loaded peptide-modified nanoparticles achieved an optimal but crucial balance between cell killing in cancerous cells and cell survival in the noncancerous ones. This appears to be because of different routes of entry and subsequent fate of the bare and peptide-modified nanoparticles in cancerous and noncancerous cells. In a TNBC mouse model, the peptide-modified system fared better than the free drug in mounting an antitumor response while not being toxic systemically.

Role of Caveolae family-related proteins in the development of breast cancer

Breast cancer has become the most significant malignant tumor threatening women's lives. Caveolae are concave pits formed by invagination of the plasma membrane that participate in many biological functions of the cell membrane, such as endocytosis, cell membrane assembly, and signal transduction. In recent years, Caveolae family-related proteins have been found to be closely related to the occurrence and development of breast cancer. The proteins associated with the Caveolae family-related include Caveolin (Cav) and Cavins. The Cav proteins include Cav-1, Cav-2 and Cav-3, among which Cav-1 has attracted the most attention as a tumor suppressor and promoting factor affecting the proliferation, apoptosis, migration, invasion and metastasis of breast cancer cells. Cav-2 also has dual functions of inhibiting and promoting cancer and can be expressed in combination with Cav-1 or play a regulatory role alone. Cav-3 has been less studied in breast cancer, and the loss of its expression can form an antitumor microenvironment. Cavins include Cavin-1, Cavin-2, Cavin-3 and Cavin-4. Cavin-1 inhibits Cav-1-induced cell membrane tubule formation, and its specific role in breast cancer remains controversial. Cavin-2 acts as a breast cancer suppressor, inhibiting breast cancer progression by blocking the transforming growth factor (TGF-β) signaling pathway. Cavin-3 plays an anticancer role in breast cancer, but its specific mechanism of action is still unclear. The relationship between Cavin-4 and breast cancer is unclear. In this paper, the role of Caveolae family-related proteins in the occurrence and development of breast cancer and their related mechanisms are discussed in detail to provide evidence supporting the further study of Caveolae family-related proteins as potential targets for the diagnosis and treatment of breast cancer.

The role of cancer-associated fibroblasts in breast cancer metastasis

Breast cancer deaths are primarily caused by metastasis. There are several treatment options that can be used to treat breast cancer. There are, however, a limited number of treatments that can either prevent or inhibit the spread of breast tumor metastases. Thus, novel therapeutic strategies are needed. Studies have increasingly focused on the importance of the tumor microenvironment (TME) in metastasis of breast cancer. As the most abundant cells in the TME, cancer-associated fibroblasts (CAFs) play important roles in cancer pathogenesis. They can remodel the structure of the extracellular matrix (ECM) and engage in crosstalk with cancer cells or other stroma cells by secreting growth factors, cytokines, and chemokines, as well as components of the ECM, which assist the tumor cells to invade through the TME and cause distant metastasis. Clinically, CAFs not only foster the initiation, growth, angiogenesis, invasion, and metastasis of breast cancer but also serve as biomarkers for diagnosis, therapy, and prediction of prognosis. In this review, we summarize the biological characteristics and subtypes of CAFs and their functions in breast cancer metastasis, focusing on their important roles in the diagnosis, prognosis, and treatment of breast cancer. Recent studies suggest that CAFs are vital partners of breast cancer cells that assist metastasis and may represent ideal targets for prevention and treatment of breast cancer metastasis.

Endorsement of TNBC Biomarkers in Precision Therapy by Nanotechnology

Breast cancer is a heterogeneous disease which accounts globally for approximately 1 million new cases annually, wherein more than 200,000 of these cases turn out to be cases of triple-negative breast cancer (TNBC). TNBC is an aggressive and rare breast cancer subtype that accounts for 10-15% of all breast cancer cases. Chemotherapy remains the only therapy regimen against TNBC. However, the emergence of innate or acquired chemoresistance has hindered the chemotherapy used to treat TNBC. The data obtained from molecular technologies have recognized TNBC with various gene profiling and mutation settings that have helped establish and develop targeted therapies. New therapeutic strategies based on the targeted delivery of therapeutics have relied on the application of biomarkers derived from the molecular profiling of TNBC patients. Several biomarkers have been found that are targets for the precision therapy in TNBC, such as EGFR, VGFR, TP53, interleukins, insulin-like growth factor binding proteins, c-MET, androgen receptor, BRCA1, glucocorticoid, PTEN, ALDH1, etc. This review discusses the various candidate biomarkers identified in the treatment of TNBC along with the evidence supporting their use. It was established that nanoparticles had been considered a multifunctional system for delivering therapeutics to target sites with increased precision. Here, we also discuss the role of biomarkers in nanotechnology translation in TNBC therapy and management.

Expression of Cav-1, MCT1, and MCT4 in Ductal Carcinoma In Situ of the Breast and Their Associations With Clinicopathologic Features

Loss of caveolin-1 (Cav-1) and upregulation of monocarboxylate transporters (MCTs, especially MCT1 and MCT4) in respectively tumor-associated stromal cells and malignant epithelial cells of invasive carcinoma have been found to play an important role in the metabolic coupling. However, this phenomenon has only been scarcely described in pure ductal carcinoma in situ (DCIS) of the breast. mRNA and protein expression levels of Cav-1, MCT1, and MCT4 in nine pairs of DCIS tissues and matched normal tissues were examined by quantitative real-time polymerase chain reaction, RNAscope in situ hybridization, and immunohistochemistry. Immunohistochemical staining of Cav-1, MCT1, and MCT4 in 79 DCIS samples was also done using tissue microarray. Cav-1 mRNA expression was significantly lower in DCIS tissues than in their corresponding normal tissues. In contrast, MCT1 and MCT4 mRNA expression levels were higher in DCIS tissues than in corresponding normal tissues. Low stromal Cav-1 expression was significantly associated with high nuclear grade. High epithelial MCT4 expression was associated with larger tumor size and human epidermal growth factor 2 positivity. At a mean follow-up of 10 years, patients with high epithelial MCT1/high epithelial MCT4 expression showed shorter disease-free survival than those with other expressions. No significant association was observed between stromal Cav-1 expression and epithelial MCT 1 or MCT4 expression. Changes in Cav-1, MCT1, and MCT4 are associated with carcinogenesis of DCIS. A high epithelial MCT1/high epithelial MCT4 expression might be associated with a more aggressive phenotype.

Early Triple-Negative Breast Cancers in a Singapore Cohort Exhibit High PIK3CA Mutation Rates Associated With Low PD-L1 Expression

Mutations in the PI3K pathway, particularly PIK3CA, were reported to be intimately associated with triple-negative breast cancer (TNBC) progression and the development of treatment resistance. We profiled PIK3CA and other genes on 166 early-stage TNBC tumors from Singapore for comparison to publicly available TNBC cohorts. These tumors were profiled transcriptionally using a NanoString panel of immune genes and multiplex immunohistochemistry, then manually scored for PD-L1-positivity using 2 clinically relevant clones, SP142 and 22C3. We discovered a higher rate of PIK3CA mutations in our TNBC cohort than in non-Asian cohorts, along with TP53, BRCA1, PTPN11, and MAP3K1 alterations. PIK3CA mutations did not affect overall or recurrence-free survival, and when compared with PIK3CA^WT tumors, there were no differences in immune infiltration. Using 2 clinically approved antibodies, PIK3CA^mut tumors were associated with PD-L1 negativity. Analysis of comutation frequencies further revealed that PIK3CA mutations tended to be accompanied by MAP kinase pathway mutation. The mechanism and impact of PIK3CA alterations on the TNBC tumor immune microenvironment and PD-L1 positivity warrant further study.

Molecular and Immunohistochemical Alterations in Breast Cancer Patients in Upper Egypt

Background

Breast cancer (BC) plays a major public health in Egyptian woman. In Upper Egypt, there is an increase in incidence of BC compared to other Egyptian areas. Triple-negative BC, estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and HER2-neu-negative, is a high-risk BC that lacks the benefit of specific therapy that targets these proteins. Accurate determination of Caveolin-1(Cav-1), Caveolin-2 (Cav-2) and HER-2/neu status have become of major clinical significance in BC by focusing about its role as a tumor marker for response to different therapies.

Methods

The present study was performed on 73 female BC patients in the South Egypt Cancer Institute. Blood samples were used for Cav-1, Cav-2, and HER-2/neu genes amplification and expression. In addition, immunohistological analysis of mammaglobin, GATA3, ER, PR, and HER-2/neu was done.

Results

There was a statistically significant association between Cav-1, 2 and HER-2/neu genes expression and the age of patients (P< 0.001). There are increase in the level of Cav-1, 2 and increase in HER-2/neu mRNA expression in groups treated with chemotherapy and group treated with both chemotherapy and radiotherapy compared to each group baseline level of genes mRNA expression before treatment. On the contrary, the group treated with chemotherapy, radiotherapy and hormonal therapy revealed increase on the level of Cav-1, 2 and HER-2/neu mRNA expression when compared with their baseline for the same patients before treatment.

Conclusions

Noninvasive molecular biomarkers such as Cav-1 and Cav-2 have been proposed for use in the diagnosis and prognosis for women with BC.

HOTAIR/miR-203/CAV1 Crosstalk Influences Proliferation, Migration, and Invasion in the Breast Cancer Cell

In recent years, malignant breast cancer metastasis has caused a great increase in mortality. Research on the genetic and molecular mechanisms of malignant breast cancer has continued to deepen, and targeted therapy has become the general trend. Among them, competing endogenous RNA (ceRNA)-related molecules have received much attention. Homeobox transcript antisense RNA (HOTAIR) has been reported to function extensively as a ceRNA in breast cancer. Notably, miR-203 and Caveolin 1 (CAV1) have also been found to play a role in breast cancer. However, the relationship between the three remains unclear. In this study, we present a new mechanic through bioinformatics tool and basic experiments: the HOTAIR/miR-203/CAV1 axis, which complemented the role network of HOTAIR as a ceRNA, thus, it will provide a novel potential idea for breast cancer research and therapy.

Caveolae-Associated Molecules, Tumor Stroma, and Cancer Drug Resistance: Current Findings and Future Perspectives

Simple Summary

Cell membranes contain small invaginations called caveolae. They are a specialized lipid domain and orchestrate cellular signaling events, mechanoprotection, and lipid homeostasis. Formation of the caveolae depends on two classes of proteins, the caveolins and cavins, which form large complexes that allow their self-assembly into caveolae. Loss of either of these two proteins leads to distortion of the caveolae structure and disruption of many physiological processes that affect diseases of the muscle, metabolic states governing lipids, and the glucose balance as well as cancers. In cancers, the expression of caveolins and cavins is heterogenous, and they undergo alterations both in the tumors and the surrounding tumor microenvironment stromal cells. Remarkably, their expression and function has been associated with resistance to many cancer drugs. Here, we summarize the current knowledge of the resistance mechanisms and how this knowledge could be applied into the clinic in future.

Abstract

The discovery of small, “cave-like” invaginations at the plasma membrane, called caveola, has opened up a new and exciting research area in health and diseases revolving around this cellular ultrastructure. Caveolae are rich in cholesterol and orchestrate cellular signaling events. Within caveola, the caveola-associated proteins, caveolins and cavins, are critical components for the formation of these lipid rafts, their dynamics, and cellular pathophysiology. Their alterations underlie human diseases such as lipodystrophy, muscular dystrophy, cardiovascular disease, and diabetes. The expression of caveolins and cavins is modulated in tumors and in tumor stroma, and their alterations are connected with cancer progression and treatment resistance. To date, although substantial breakthroughs in cancer drug development have been made, drug resistance remains a problem leading to treatment failures and challenging translation and bench-to-bedside research. Here, we summarize the current progress in understanding cancer drug resistance in the context of caveola-associated molecules and tumor stroma and discuss how we can potentially design therapeutic avenues to target these molecules in order to overcome treatment resistance.

Intratumoral CD39+CD8+ T Cells Predict Response to Programmed Cell Death Protein-1 or Programmed Death Ligand-1 Blockade in Patients With NSCLC

INTRODUCTION

Programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) blockade is currently widely used in the treatment of metastatic NSCLC. Despite available biomarker stratification, clinical responses vary. Thus, the search for novel biomarkers with improved response prediction is ongoing. Previously, using mass cytometry or cytometry by time-of-flight (CyTOF), our group demonstrated that CD39⁺CD8⁺ immune cells represent tumor antigen-specific, cytotoxic T cells in treatment-naive NSCLC. We hypothesized that accurate quantitation of this T cell subset would predict immunotherapy outcome.

METHODS

To translate this to a clinical setting, the present study compared CyTOF data with a range of clinically relevant methods, including conventional immunohistochemistry (IHC), multiplex IHC or immunofluorescence (mIHC), and gene expression assay by NanoString.

RESULTS

Quantification using mIHC but not conventional IHC or NanoString correlated with the CyTOF results. The specificity and sensitivity of mIHC were then evaluated in a separate retrospective NSCLC cohort. CD39⁺CD8⁺ T cell proportion, as determined by mIHC, successfully stratified responders and nonresponders to PD-1 or PD-L1 inhibitors (objective response rate of 63.6%, compared with 0% for the negative group). This predictive capability was independent from other confounding factors, such as total CD8⁺ T cell proportion, CD39⁺ lymphocyte proportion, PD-L1 positivity, EGFR mutation status, and other clinicopathologic parameters.

CONCLUSIONS

Our results suggest that the mIHC platform is a clinically relevant method to evaluate CD39⁺CD8⁺ T cell proportion and that this marker can serve as a potential biomarker that predicts response to PD-1 or PD-L1 blockade in patients with NSCLC. Further validation in additional NSCLC cohorts is warranted.

Downregulation of caveolin-1 promotes murine breast cancer cell line progression by highly glycosylated CD147

Caveolin-1 (CAV-1) can extensively regulate lipid transportation, cell growth and cell death. In the present study, we revealed a novel function of CAV-1 in inhibiting glycosylation of other molecules in murine breast cancer cell line. After the silencing of CAV-1, we found that the mRNA and protein expressions of cluster of differentiation 147 (CD147) and its related molecules (MCT4, matrix metalloproteinase MMP2 and MMP9) increased in the breast cancer cells. Meanwhile, the migration and invasion of the breast cancer cells were significantly enhanced assessed by cell wound healing experiment and transwell assays. Further, the gelatin zymography and lactate assay in the cells also showed the strengthened enzyme activity of MMP9 and the increased extracellular lactate concentration, respectively, after the silencing of CAV-1. Notably, the glycosylation level of CD147 overtly increased after the inhibition of CAV-1 detected by Western Blot analysis, whereas upregulation of CAV-1 did the opposite. Therefore, the findings suggest that the downregulation of CAV-1 can promote breast cancer cell progression probably by highly glycosylated CD147.

Caveolin-1 function at the plasma membrane and in intracellular compartments in cancer

Caveolin-1 (CAV1) is commonly considered to function as a cell surface protein, for instance in the genesis of caveolae. Nonetheless, it is also present in many intracellular organelles and compartments. The contributions of these intracellular pools to CAV1 function are generally less well understood, and this is also the case in the context of cancer. This review will summarize literature available on the role of CAV1 in cancer, highlighting particularly our understanding of the canonical (CAV1 in the plasma membrane) and non-canonical pathways (CAV1 in organelles and exosomes) linked to the dual role of the protein as a tumor suppressor and promoter of metastasis. With this in mind, we will focus on recently emerging concepts linking CAV1 function to the regulation of intracellular organelle communication within the same cell where CAV1 is expressed. However, we now know that CAV1 can be released from cells in exosomes and generate systemic effects. Thus, we will also elaborate on how CAV1 participates in intracellular communication between organelles as well as signaling between cells (non-canonical pathways) in cancer.

The mechanism underlying hypaconitine-mediated alleviation of pancreatitis-associated lung injury through up-regulating aquaporin-1/TNF-α

BACKGROUND/AIMS

Acute pancreatitis-associated lung injury (APALI) is one of the most common and most dangerous form of extra-pancreatic organ damage in severe acute pancreatitis (SAP). The treatment options for SAP were limited thus far; as a result, approximately 60%-80% of patients with SAP would die within a week. Hypaconitine (HC), one of the most important active ingredients in a Mongolian traditional medicine Radix Aconiti Kusnezoffii has an excellent anti-inflammatory effect.

MATERIALS AND METHODS

To ascertain whether HC has a protective effect against APALI, we investigated the therapeutic effects and the underlying mechanisms in vivo and in vitro and attempted to elucidate the mechanism in detail. In this study, APALI rats and human pulmonary microvascular endothelial cells were treated with therapeutic doses of HC after establishing a model with sodium taurocholate and lipopolysaccharide, respectively.

RESULTS

Serum amylase and lipase activity, lung wet/dry weight ratio, lung myeloperoxidase activity, and pancreatic and lung histopathological changes showed that HC alleviated APALI in a dose-dependent way, which can be abolished by an aquaporin-1 (AQP-1) knockdown. The results of the reverse transcriptase polymerase chain reaction, Western blot, and immunohistochemical staining confirmed the expression of AQP-1, a kind of transmembrane protein that mainly distributed in the membranes of pulmonary cells and contributed to maintain water balance in the body by interacting with tumor necrosis factor-alpha (TNF-α), is negatively associated with APALI. On the contrary, HC treatment up-regulated AQP-1 expression and down-regulated the TNF-α expression as a consequence in APALI.

CONCLUSION

These results suggest that HC has a good anti-inflammatory therapeutic effect on APALI with a possible underlying mechanism that affects the AQP-1/TNF-α pathway.

Immunohistochemical scoring of CD38 in the tumor microenvironment predicts responsiveness to anti-PD-1/PD-L1 immunotherapy in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-associated mortality globally. Immune-checkpoint blockade (ICB) is one of the systemic therapy options for HCC. However, response rates remain low, necessitating robust predictive biomarkers. In the present study, we examined the expression of CD38, a molecule involved in the immunosuppressive adenosinergic pathway, on immune cells present in the tumor microenvironment. We then investigated the association between CD38 and ICB treatment outcomes in advanced HCC.

Methods

Clinically annotated samples from 49 patients with advanced HCC treated with ICB were analyzed for CD38 expression using immunohistochemistry (IHC), multiplex immunohistochemistry/immunofluorescence (mIHC/IF) and multiplex cytokine analysis.

Results

IHC and mIHC/IF analyses revealed that higher intratumoral CD38⁺ cell proportion was strongly associated with improved response to ICB. The overall response rates to ICB was significantly higher among patients with high proportion of total CD38⁺cells compared with patients with low proportion (43.5% vs 3.9%, p=0.019). Higher responses seen among patients with a high intratumoral CD38⁺cell proportion translated to a longer median progression-free survival (mPFS, 8.21 months vs 1.64 months, p=0.0065) and median overall survival (mOS, 19.06 months vs 9.59 months, p=0.0295). Patients with high CD38⁺CD68⁺macrophage density had a better mOS of 34.43 months compared with 9.66 months in patients with low CD38⁺CD68⁺ macrophage density. CD38^hi macrophages produce more interferon γ (IFN-γ) and related cytokines, which may explain its predictive value when treated with ICB.

Conclusions

A high proportion of CD38⁺ cells, determined by IHC, predicts response to ICB and is associated with superior mPFS and OS in advanced HCC.

miR‑96 exerts an oncogenic role in the progression of cervical cancer by targeting CAV‑1

Cervical cancer is the 4th most common malignant tumor type affecting women worldwide; however, its molecular mechanisms are not fully understood. Previous studies have indicated that microRNAs (miRs) serve crucial roles in the cellular functions of tumors. miR‑96 is involved in the tumorigenesis of many cancer types. The aim of the present study was to investigate the role and mechanism of miR‑96 in the progression of cervical cancer. The present results suggested that overexpression of miR‑96 significantly enhanced the proliferative, migratory and invasive abilities of cervical cancer cells, while inhibiting miR‑96 had the opposite effects. Additionally, activation of the Akt/mTOR signaling pathway was enhanced by miR‑96 overexpression, while it was inhibited by the miR‑96 inhibitor. Moreover, it was identified that miR‑96 may directly target caveolin‑1 (CAV‑1) to decrease its expression level. Furthermore, overexpression of CAV‑1 could reverse the increase in cell proliferation, migration and invasion induced by miR‑96, as well as the upregulation of the Akt/mTOR signaling pathway. In conclusion, the present results suggested that miR‑96 may have an oncogenic role in the progression of cervical cancer by targeting CAV‑1. Therefore, miR‑96 may be a potential target for cervical cancer therapy.

Caveolin-1: a multifaceted driver of breast cancer progression and its application in clinical treatment

Human breast cancer is one of the most frequent cancer diseases and causes of death among female population worldwide. It appears at a high incidence and has a high malignancy, mortality, recurrence rate and poor prognosis. Caveolin-1 (Cav1) is the main component of caveolae and participates in various biological events. More and more experimental studies have shown that Cav1 plays a critical role in the progression of breast cancer including cell proliferation, apoptosis, autophagy, invasion, migration and breast cancer metastasis. Besides, Cav1 has been found to be involved in chemotherapeutics and radiotherapy resistance, which are still the principal problems encountered in clinical breast cancer treatment. In addition, stromal Cav1 may be a potential indicator for breast cancer patients’ prognosis. In the current review, we cover the state-of-the-art study, development and progress on Cav1 and breast cancer, altogether describing the role of Cav1 in breast cancer progression and application in clinical treatment, in the hope of providing a basis for further research and promoting CAV1 gene as a potential target to diagnose and treat aggressive breast cancers.

Prognostic value of CD8 + PD-1+ immune infiltrates and PDCD1 gene expression in triple negative breast cancer

The role of programmed cell death protein-1 (PD-1)/programmed cell death ligand 1 (PD-L1) in triple negative breast cancer (TNBC) remains to be fully understood. In this study, we investigated the role of PD-1 as a prognostic marker for TNBC in an Asian cohort (n = 269). Samples from patients with TNBC were labeled with antibodies against PD-L1 and PD-1, and subjected to NanoString assays to measure the expression of immune-related genes. Associations between disease-free survival (DFS), overall survival (OS) and biomarker expression were investigated. Multivariate analysis showed that tumors with high PD-1⁺ immune infiltrates harbored significantly increased DFS, and this increase was significant even after controlling for clinicopathological parameters (HR 0.95; P = 0.030). In addition, the density of cells expressing both CD8 and PD-1, but not the density of CD8⁻PD-1⁺ immune infiltrates, was associated with improved DFS. Notably, this prognostic significance was independent of clinicopathological parameters and the densities of total CD8⁺ cell (HR 0.43, P = 0.011). At the transcriptional level, high expression of PDCD1 within the tumor was significantly associated with improved DFS (HR 0.38; P = 0.027). In line with these findings, high expression of IFNG (HR 0.38; P = 0.001) and IFN signaling genes (HR 0.46; p = 0.027) was also associated with favorable DFS. Inclusion of PD-1 immune infiltrates and PDCD1 gene expression added significant prognostic value for DFS (ΔLRχ² = 6.35; P = 0.041) and OS (ΔLRχ² = 9.53; P = 0.008), beyond that provided by classical clinicopathological variables. Thus, PD-1 mRNA and protein expression status represent a promising, independent indicator of prognosis in TNBC.

Caveolin-1-Knockout Mouse as a Model of Inflammatory Diseases

Caveolin-1 (CAV1) is the scaffold protein of caveolae, which are minute invaginations of the cell membrane that are involved in endocytosis, cell signaling, and endothelial-mediated inflammation. CAV1 has also been reported to have a dual role as either a tumor suppressor or tumor promoter, depending on the type of cancer. Inflammation is an important player in tumor progression, but the role of caveolin-1 in generating an inflammatory milieu remains poorly characterized. We used a caveolin-1-knockout (CAV1^-/-) mouse model to assess the inflammatory status via the quantification of the pro- and anti-inflammatory cytokine levels, as well as the ability of circulating lymphocytes to respond to nonspecific stimuli by producing cytokines. Here, we report that the CAV1^-/- mice were characterized by a low-grade systemic proinflammatory status, with a moderate increase in the IL-6, TNF-α, and IL-12p70 levels. CAV1^-/- circulating lymphocytes were more prone to cytokine production upon nonspecific stimulation than the wild-type lymphocytes. These results show that CAV1 involvement in cell homeostasis is more complex than previously revealed, as it plays a role in the inflammatory process. These findings indicate that the CAV1^-/- mouse model could prove to be a useful tool for inflammation-related studies.

The diversity in the expression profile of caveolin II transcripts, considering its new transcript in breast cancer

Most studies have revealed the effects of caveolins in cancer inhibition. However, due to a lack of reports about their new transcripts, their presence and their effects on different cancers are unclear. This study was conducted to evaluate the cavolin-2 (cav-2) transcripts expression changes in tumoral and corresponding tissues and in contralateral breast, to investigate their variation associated with the variation of caveolin-1 (cav-1) expression in breast cancer. There were 40 breast-derived tumoral, corresponding, and contralateral tissues obtained from the patients with breast cancer. The RNA and proteins were extracted from these samples. So, cav-1 and cav-2 transcripts' variation were assessed in whole tumoral, corresponding, and contralateral breast. Also, their expression modifications were evaluated via the Western blotting technique. The results derived from this study verified the presence of transcript III of cav-2 for the first time, which was reported only in the gene bank, but we could not detect and validate any protein associated with these transcripts. Also, the decreasing trend of cav-1 and the cav-2 (transcripts I and II) were observed in tumoral tissues compared to unaffected tissues especially in stages I and II. It seems that the descending expression levels of cav-1 and cav-2 (transcript I, II) besides the lasting expression of cav-2 (transcript III) are associated with the incidence and promotion of breast cancer, especially in the initial stages of breast cancer. So, this may show a potential in determining the patients who can undergo the prophylactic mastectomy. Moreover, the results of the study demonstrated that transcript III may be a candidate as a non-coding RNA.