Knockdown of Osteopontin Chemosensitizes MDA-MB-231 Cells to Cyclophosphamide by Enhancing Apoptosis Through Activating p38 MAPK Pathway

TempEasy 3D Hydrogel Coculture System Provides Mechanistic Insights into Prostate Cancer Bone Metastasis

Patients diagnosed with advanced prostate cancer (PCa) often experience incurable bone metastases; however, a lack of relevant experimental models has hampered the study of disease mechanisms and the development of therapeutic strategies. In this study, we employed the recently established Temperature-based Easy-separable (TempEasy) 3D cell coculture system to investigate PCa bone metastasis. Through coculturing PCa and bone cells for 7 days, our results showed a reduction in PCa cell proliferation, an increase in neovascularization, and an enhanced metastasis potential when cocultured with bone cells. Additionally, we observed increased cell proliferation, higher stemness, and decreased bone matrix protein expression in bone cells when cocultured with PCa cells. Furthermore, we demonstrated that the stiffness of the extracellular matrix had a negligible impact on molecular responses in both primary (PCa cells) and distant malignant (bone cells) sites. The TempEasy 3D hydrogel coculture system is an easy-to-use and versatile coculture system that provides valuable insights into the mechanisms of cell-cell communication and interaction in cancer metastasis.

PM2.5 promotes apoptosis of alveolar epithelial cells via targeting ROS/p38 signaling pathway and thus leads to emphysema in mice

BACKGROUND

The aim of this study was to uncover the ability of PM2.5 exposure to induce apoptosis in alveolar epithelial cells by stimulating excessive production of reactive oxygen species (ROS), thus activating p38 to result in emphysema in mice.

METHODS

Male BALB/c mice with 6-8-week-old were exposed to 200 TPM mg/L PM2.5 for 12 weeks. Lung tissues of mice were harvested after sacrifice. Hematoxylin and eosin staining was conducted for observing alveolar structure change. Protein levels of p-p38 and p38, as well as ROS level in mouse liver tissues were determined. A549 cells were exposed to different doses of PM2.5, followed by ROS detection, protein level detection of p-p38 and p38, and apoptosis determination. After transfection of si-p38, protein level of clv-caspase3 and apoptotic rate in PM2.5-exposed A549 cells were assessed.

RESULTS

After 12-week exposure to PM2.5, enlarged alveolar space, elevated ROS level in lung tissues and activated p38 were observed in mice. In PM2.5-exposed A549 cells, ROS level, p-p38 expression and apoptotic rate were dose-dependently enhanced. The antioxidant NAC reversed the above changes in PM2.5-exposed A549 cells. Silence of p38 reversed the enhanced clv-claspase3 level and apoptotic rate in PM2.5-exposed A549 cells.

CONCLUSIONS

PM2.5 exposure elevates ROS level in lung tissues, and activates p38, thus leading to apoptosis of alveolar epithelial cells. PM2.5 finally results in the development of emphysema in mice.

The bovine dialyzable leukocyte extract, immunepotent CRP, synergically enhances cyclophosphamide-induced breast cancer cell death, through a caspase-independent mechanism

Breast cancer (BC) is one of the leading causes of cancer death worldwide. Cyclophosphamide (CTX) remains a mainstay in cancer therapy despite harmful adverse effects and cell death-resistances. To face this, combinational therapy of chemotherapies and immunotherapies has been proposed. IMMUNEPOTENT CRP (ICRP) is an immunotherapy that has cytotoxic effects in several cancer cells without affecting peripheral blood mononuclear cells (PBMC) and CD3+ cells. The aim of this study was to evaluate cytotoxicity, the type of cytotoxic effect, and several features involved in cell death induced by the combination of CTX with ICRP (ICRP+CTX) in breast cancer cells as well as their effect on healthy cells. For this purpose, human and murine breast cancer cells, MCF-7, MDA-MB-231 and 4T1, or PBMC were treated for 24 hours with ICRP, CTX or ICRP+CTX in different combination ratios for the assessment of cell death. Flow cytometry and microscopy were used to determine biochemical and morphological characteristics of cell death. Assays showed that ICRP in combination with CTX induce potentiated cell death manifested with morphological changes, loss of mitochondrial membrane potential, reactive oxygen species (ROS) production, and caspase activation. In addition, it was determined that ICRP+CTX-cell death is caspase-independent in all the breast cancer cells assessed. On the other hand, ICRP did not affect CTX-cytotoxicity in PBMC. For all the above, we can propose that the combination of ICRP with CTX an effective combination therapy, promoting their use even in tumoral cells with defects on proteins implicated in the apoptotic pathway.

The multifaceted role of Matricellular Proteins in health and cancer, as biomarkers and therapeutic targets

The extracellular matrix (ECM) is composed of a mesh of proteins, proteoglycans, growth factors, and other secretory components. It constitutes the tumor microenvironment along with the endothelial cells, cancer-associated fibroblasts, adipocytes, and immune cells. The proteins of ECM can be functionally classified as adhesive proteins and matricellular proteins (MCP). In the tumor milieu, the ECM plays a major role in tumorigenesis and therapeutic resistance. The current review encompasses thrombospondins, osteonectin, osteopontin, tenascin C, periostin, the CCN family, laminin, biglycan, decorin, mimecan, and galectins. The matrix metalloproteinases (MMPs) are also discussed as they are an integral part of the ECM with versatile functions in the tumor stroma. In this review, the role of these proteins in tumor initiation, growth, invasion and metastasis have been highlighted, with emphasis on their contribution to tumor therapeutic resistance. Further, their potential as biomarkers and therapeutic targets based on existing evidence are discussed. Owing to the recent advancements in protein targeting, the possibility of agents to modulate MCPs in cancer as therapeutic options are discussed.

The Role of Extracellular Matrix Proteins in Breast Cancer

The extracellular matrix is a structure composed of many molecules, including fibrillar (types I, II, III, V, XI, XXIV, XXVII) and non-fibrillar collagens (mainly basement membrane collagens: types IV, VIII, X), non-collagenous glycoproteins (elastin, laminin, fibronectin, thrombospondin, tenascin, osteopontin, osteonectin, entactin, periostin) embedded in a gel of negatively charged water-retaining glycosaminoglycans (GAGs) such as non-sulfated hyaluronic acid (HA) and sulfated GAGs which are linked to a core protein to form proteoglycans (PGs). This highly dynamic molecular network provides critical biochemical and biomechanical cues that mediate the cell–cell and cell–matrix interactions, influence cell growth, migration and differentiation and serve as a reservoir of cytokines and growth factors’ action. The breakdown of normal ECM and its replacement with tumor ECM modulate the tumor microenvironment (TME) composition and is an essential part of tumorigenesis and metastasis, acting as key driver for malignant progression. Abnormal ECM also deregulate behavior of stromal cells as well as facilitating tumor-associated angiogenesis and inflammation. Thus, the tumor matrix modulates each of the classically defined hallmarks of cancer promoting the growth, survival and invasion of the cancer. Moreover, various ECM-derived components modulate the immune response affecting T cells, tumor-associated macrophages (TAM), dendritic cells and cancer-associated fibroblasts (CAF). This review article considers the role that extracellular matrix play in breast cancer. Determining the detailed connections between the ECM and cellular processes has helped to identify novel disease markers and therapeutic targets.

Cyclophosphamide Induces the Ferroptosis of Tumor Cells Through Heme Oxygenase-1

Ferroptosis has been implicated in the therapeutic responses of various types of tumors. Cyclophosphamide (CTX), one of the most successful antitumor agents, is widely used to treat both hematopoietic and solid tumors. In this study, we revealed the ferroptosis pathway targeted by CTX treatment in tumor cells and clarified its mechanisms. Cell viability was remarkably suppressed by CTX, accompanied by the accumulation of intracellular iron and reactive oxygen species (ROS), reduced glutathione levels, deformed mitochondria and a loss of the mitochondrial membrane potential. These effects were impeded by the ferroptosis inhibitors ferrostatin-1 (Fer1) and deferoxamine (DFO). Moreover, CTX treatment obviously upregulated nuclear factor E2 related factor 2 (NRF2) and heme oxygenase-1 (HMOX-1) expression. Additionally, the HMOX-1 inducer Hemin notably enhanced CTX-mediated tumor inhibition in vitro and in vivo through a mechanism that involved interfering with the ferroptosis process. Therefore, our findings indicated ferroptosis induction by CTX through the activation of the NRF2/HMOX-1 pathway, which might provide a potential strategy for tumor chemotherapy.

(cRGD)2 peptides modified nanoparticles increase tumor-targeting therapeutic effects by co-delivery of albendazole and iodine-131

Albendazole (ABZ), a clinical antiparasitic drug, has shown potential antitumor effects in various tumors. Herein, we prepared dimeric cRGD [(cRGD)2] modified human serum albumin (HSA) nanosystem to co-delivery of albendazole (ABZ) and iodine-131 (131I) for chemoradiotherapy of triple-negative breast cancer (TNBC). HSA@ABZ NPs were synthesized by the self-assembly method. 131I-(cRGD)2/HSA@ABZ NPs were fabricated through covalently binding HSA@ABZ NPs with (cRGD)2 peptides, followed by chloramine T direct labeling with 131I. In vitro therapeutic effects on TNBC (MDA-MB-231 and 4T1 cells) were determined using MTT assay, crystal violet assay, wound-healing assay and western blotting analysis. In vivo treatment was performed using 4T1-bearing mice, and the tumor-targeting efficacy was assessed by gamma imaging. The distribution of NPs was quantitatively analyzed by detecting the gamma counts in tumor and main organs. The nanoparticles possessed negative charge, moderate size and good polydispersity index. Dual responding to pH and redox, the in vitro release rate of ABZ was more than 80% in 72 h. In vitro, NPs inhibited the proliferation of TNBC cells in a concentration-dependent manner and decreased cell migration. Western blotting analysis showed that the NPs, as well as free ABZ, cell-dependently induced autophagy and apoptosis by restraining or promoting the expression of p-p38 and p-JNK MAPK. In vivo, gamma imaging exhibited an earlier and denser radioactivity accumulation in tumor of 131I-(cRGD)2/HSA@ABZ NPs compared to NPs free of (cRGD)2 conjugating. Furthermore, 131I-(cRGD)2/HSA@ABZ NPs significantly suppressed tumor growth by restraining proliferation and promoting apoptosis in vivo. Our study suggested that the nanoparticles we developed enhanced tumor-targeting of ABZ and increased antitumor effects by combination of chemotherapy and radiotherapy.

Prognostic and predictive significance of osteopontin in malignant neoplasms

Osteopontin is an extracellular matrix protein which is produced by different types of cells and plays an important functional role in many biological processes. This review discusses the main functions of osteopontin, its role in the progression and chemoresistance of malignant neoplasms, in the regulation of epithelial-mesenchymal transition, angiogenesis, and the body’s immune response to the tumor. The article considers the currently known mechanisms by which osteopontin affects to the survival, mobility and invasion of tumor cells, to tumor sensitivity to drug treatment, as well as the prospects for a integrated study of the predictive significance of osteopontin, markers of hypoxia, angiogenesis, epithelial- mesenchymal transition, and immunological tolerance.

Evaluation of local and circulating osteopontin in malignant and benign primary bone tumors

Purpose

The development of novel and efficient biomarkers for primary bone cancers is of grave importance.

Methods

The expression pattern of osteopontin (OPN) was investigated in the 153 patients with benign (n = 72) and malignant (n = 81) primary bone cancers. Both local and circulating OPN mRNA expression levels and their protein concentration in serum and tumor site were assessed using real-time qRT-PCR, ELISA, and immunohistochemistry techniques, respectively. As a control, 29 healthy individuals were considered. The number of 153 tumor tissue specimens and the 153 paired margins were taken on surgical resection from the patients. 153 blood samples were also drained from all participants, then peripheral blood mononuclear cells (PBMC) and sera were separated.

Results

The mean mRNA expression was significantly higher in all of the cancerous tissues than the paired margins and the PBMC of the patients than the controls. Consistently, the protein concentrations of OPN in serum and tumor tissues were significantly higher in the patients. Furthermore, the malignant cases had significantly elevated the mRNA levels and the protein compared to the benign cases. OPN could potentially differentiate the patients from the controls with 100% sensitivity and specificity in serum. Moreover, OPN could predict some of the malignant cases' clinicopathological features, including metastasis, recurrence, grade, and response to chemotherapy.

Conclusions

In conclusion, OPN might be involved in the pathogenesis of primary bone tumors and can be considered as a potential biomarker to bone cancer diagnosis.

Tumor-derived osteopontin drives the resident fibroblast to myofibroblast differentiation through Twist1 to promote breast cancer progression

Tumor-stroma interactions are important determinants for the disease course in cancer. While stromal influence has been known to often play a tumor-promoting role, incomplete mechanistic insight into this phenomenon has prevented its therapeutic targeting. Stromal fibroblasts can be activated by tumor cells to differentiate into cancer-associated fibroblasts (CAFs), that exhibit the traits of myofibroblasts, and in turn, they increase cancer aggressiveness. Here, we report the crosstalk between the cancer cells and stromal fibroblasts that leads to tumor progression. The process is initiated by secretion of a chemokine like protein, osteopontin (OPN) from the cancer cells that differentiates the fibroblasts to myofibroblasts. Tumor-derived OPN achieves this transition by engaging CD44 and αvβ3 integrins on the fibroblast surface, which mediates signaling via Akt and ERK to induce Twist1-dependent gene expression. The OPN-driven CAFs then secrete CXCL12, which in turn triggers epithelial to mesenchymal transition (EMT) in the tumor cells. OPN, produced by the cancer cells, and CXCL12, secreted by activated fibroblasts, are necessary and sufficient to perpetuate the crosstalk. Knocking out OPN in carcinogen-induced mammary tumors or knocking down OPN in cancer cells and fibroblast co-implanted xenografts abrogates myofibroblast differentiation, Twist1, and CXCL12 expression. OPN expression is correlated with CAF-specific gene signature as shown by breast tumor tissue microarray consisting of 100 patient specimens. Bioinformatics analyses have confirmed that the expression of OPN is significantly correlated with the expression of myofibroblast-specific markers as demonstrated in human breast carcinoma dataset of 2509 patients. Our findings describe OPN and CXCL12 act as compelling targets to curb the tumor-promoting features of the stromal components and further suggested that OPN-regulated CXCL12 network might act as potential therapeutic target for the management of CAF-mediated breast cancer progression.

Osteopontin: A Key Regulator of Tumor Progression and Immunomodulation

Simple Summary

Anti-PD-1/PD-L1 and anti-CTLA-4-based immune checkpoint blockade (ICB) immunotherapy have recently emerged as a breakthrough in human cancer treatment. Durable efficacy has been achieved in many types of human cancers. However, not all human cancers respond to current ICB immunotherapy and only a fraction of the responsive cancers exhibit efficacy. Osteopontin (OPN) expression is highly elevated in human cancers and functions as a tumor promoter. Emerging data suggest that OPN may also regulate immune cell function in the tumor microenvironment. This review aims at OPN function in human cancer progression and new findings of OPN as a new immune checkpoint. We propose that OPN compensates PD-L1 function to promote tumor immune evasion, which may underlie human cancer non-response to current ICB immunotherapy.

Abstract

OPN is a multifunctional phosphoglycoprotein expressed in a wide range of cells, including osteoclasts, osteoblasts, neurons, epithelial cells, T, B, NK, NK T, myeloid, and innate lymphoid cells. OPN plays an important role in diverse biological processes and is implicated in multiple diseases such as cardiovascular, diabetes, kidney, proinflammatory, fibrosis, nephrolithiasis, wound healing, and cancer. In cancer patients, overexpressed OPN is often detected in the tumor microenvironment and elevated serum OPN level is correlated with poor prognosis. Initially identified in activated T cells and termed as early T cell activation gene, OPN links innate cells to adaptive cells in immune response to infection and cancer. Recent single cell RNA sequencing revealed that OPN is primarily expressed in tumor cells and tumor-infiltrating myeloid cells in human cancer patients. Emerging experimental data reveal a key role of OPN is tumor immune evasion through regulating macrophage polarization, recruitment, and inhibition of T cell activation in the tumor microenvironment. Therefore, in addition to its well-established direct tumor cell promotion function, OPN also acts as an immune checkpoint to negatively regulate T cell activation. The OPN protein level is highly elevated in peripheral blood of human cancer patients. OPN blockade immunotherapy with OPN neutralization monoclonal antibodies (mAbs) thus represents an attractive approach in human cancer immunotherapy.

Recent Advances in Liver Cancer Stem Cells: Non-coding RNAs, Oncogenes and Oncoproteins

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide, with high morbidity, relapse, metastasis and mortality rates. Although liver surgical resection, transplantation, chemotherapy, radiotherapy and some molecular targeted therapeutics may prolong the survival of HCC patients to a certain degree, the curative effect is still poor, primarily because of tumor recurrence and the drug resistance of HCC cells. Liver cancer stem cells (LCSCs), also known as liver tumor-initiating cells, represent one small subset of cancer cells that are responsible for disease recurrence, drug resistance and death. Therefore, understanding the regulatory mechanism of LCSCs in HCC is of vital importance. Thus, new studies that present gene regulation strategies to control LCSC differentiation and replication are under development. In this review, we provide an update on the latest advances in experimental studies on non-coding RNAs (ncRNAs), oncogenes and oncoproteins. All the articles addressed the crosstalk between different ncRNAs, oncogenes and oncoproteins, as well as their upstream and downstream products targeting LCSCs. In this review, we summarize three pathways, the Wnt/β-catenin signaling pathway, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, and interleukin 6/Janus kinase 2/signal transducer and activator of transcription 3 (IL6/JAK2/STAT3) signaling pathway, and their targeting gene, c-Myc. Furthermore, we conclude that octamer 4 (OCT4) and Nanog are two important functional genes that play a pivotal role in LCSC regulation and HCC prognosis.

Osteopontin level and promoter polymorphism in patients with metastatic breast cancer

Background

Cancer initiation typically occurs when a proto-oncogene's coding region undergoes mutation, resulting in uncontrollable cell growth and division, or when a tumour suppressor gene's coding region is affected by a mutation that inhibits activity of the resulting gene product. The pathophysiologic result is, respectively, exaggerated cell-cycle growth or deficient programmed cell death. Osteopontin (opn) is an integrin-binding phosphoprotein that is expressed on the surface of normal cells. Osteopontin has a major role in diverse tumour components, especially those implicated in invasion and metastasis. In the present study, we aimed to illustrate the value of opn as a possible contributor in breast cancer (bca).

Methods

This prospective study included 115 patients newly diagnosed with bca and distant metastasis who were recruited from the Oncology Center, Mansoura University, and the Department of Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Egypt. The patients recruited had been diagnosed with disseminated visceral metastasis (visceral crisis), with or without bone metastasis; patients with cranial metastasis were excluded from the study. All patients received first-line chemotherapy with docetaxel 75 mg/m2 plus cisplatin 75 mg/m2 or carboplatin 6 auc (area under the curve) on day 1 every 21 days for a maximum of 6 cycles or till development of toxicity. Trastuzumab (in cases of her2-positive disease) was given whenever possible (if government assistance or personal finances permitted). Serum levels of opn were assessed by enzyme-linked immunosorbent assay (elisa) before treatment was started. A group of 30 matched healthy women whose median serum opn level was 15 ng/dL were included, and that level was therefore defined as the cut-off value. In addition, opn gene mutation was determined by polymerase chain reaction (pcr). Correlations of pretreatment serum opn and opn gene mutation with various patient clinicopathologic variables, response to the treatment, progression-free survival (pfs), and overall survival (os) were assessed.

Results

Mean serum opn was highest in her2-amplified bca (64.4 ± 42.3 ng/dL), and then in triple-negative bca (55.9 ± 34.7 ng/dL), followed by the luminal B and A subtypes (38.4 ± 33.1 ng/dL and 36.3 ± 32.2 ng/dL respectively, p = 0.017). Testing by pcr revealed that opn gene mutation was highest in triple-negative bca (85% opn mutant vs. 15% non-mutant), and then in her2-overexpressed bca (80% opn mutant vs. 20% non-mutant), followed by luminal B bca (61.9% opn mutant vs. 38.1% non-mutant); the least expression was detected in luminal A bca (57.9% opn mutant vs. 42.1% non-mutant). Interestingly, patients with high serum opn and opn gene mutation experienced both poor pfs (median: 12 months vs. 14 months; p = 0.001) and poor os (median: 14 months vs. 18 months; p = 0.001). Moreover, participants with opn gene mutation experienced a poor response: of those with progressive disease, 74% had opn mutation and 26% had unmutated opn (p = 0.04). Additionally, high pretreatment serum opn was correlated with poor treatment response: 49.1 ± 33.8 ng/dL in patients with progressive disease and 35.5 ± 34.3 ng/dL in those who achieved a complete response, a partial response, or stable disease (p = 0.05). Strong concordance was found between high serum opn and opn gene mutation in 69 tumours (79.3%), and strong concordance was detected between normal or low serum opn and non-mutant opn in 28 tumours (60.8%).

Conclusions

The current prospective work helps to highlight opn as a valid prognostic biomarker for patients with metastatic bca and reveals that high pretreatment serum opn and opn gene mutation are both strongly linked with poor response and survival. Concordance between elisa and pcr results indicates that either method can be used for the evaluation of opn. Increased opn gene mutation in triple-negative bca could assist in tailoring the treatment response in this very aggressive tumour subtype and could be considered a targetable molecule in future studies.

Dihydroartemisinin Modulates Apoptosis and Autophagy in Multiple Myeloma through the P38/MAPK and Wnt/β-Catenin Signaling Pathways

Dihydroartemisinin (DHA), an active metabolite and derivative of artemisinin, is the most effective antimalarial drug and has strong antitumor activity in various tumor types. It has recently been reported that DHA can induce autophagy and has significant effects on multiple myeloma (MM), but the mechanisms and the relationship between the autophagy and apoptosis induced by DHA remain to be elucidated. Herein, we demonstrated that DHA significantly induces cell death in a dose- and time-dependent manner via the extrinsic and intrinsic apoptosis pathways. Moreover, DHA-induced autophagy, which plays a prodeath role in MM, can regulate canonical apoptosis and vice versa. Furthermore, the P38/MAPK signaling pathway is responsible for decreased autophagy and increased apoptosis. DHA induces autophagy and apoptosis also through the inhibition of the Wnt/β-catenin signaling pathway. In addition, DHA shows a strong effect in a xenograft mouse model. Collectively, these findings reveal that DHA, as an artemisinin-based drug, could be an effective and safe therapeutic agent for MM.

PI16 attenuates response to sorafenib and represents a predictive biomarker in hepatocellular carcinoma

Sorafenib has become the only FDA‐approved first‐line therapy for advanced hepatocellular carcinoma (HCC) for more than 10 years, but there is still no validated predictive or prognostic marker. Peptidase inhibitor 16 (PI16) is a functionally unknown gene in cancer research. This study aimed to determine the exact function of PI16 in HCC and whether it can represent as a biomarker for sorafenib response. We found that PI16 was over expressed in HCC tissues vs paired normal tissues. PI16 knockdown sensitize HCC cells to sorafenib treatment both in vitro and in vivo, whereas ectopic PI16 expression produced the opposite effect. Mechanistically, PI16 could suppress p38 MAPK/caspase‐dependent apoptosis in this process, and p38 MAPK inhibitor reversed the sorafenib sensitive phenotype caused by PI16 inhibition. Clinically, immunohistochemistry was used to detect PI16 levels in resected patients with HCC prior to sorafenib treatment. We showed that high PI16 levels represented an independent risk factor for disease progression in patients treated with sorafenib. Patients with low PI16 showed significantly better progression free survival and overall survival after sorafenib therapy. In conclusion, PI16 attenuates response to sorafenib treatment in HCC, and may be a helpful prognostic biomarker of sorafenib treatment.

Osteopontin Mediates Cetuximab Resistance via the MAPK Pathway in NSCLC Cells

Background

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The high expression of osteopontin (OPN) is an important factor that aggravates drug resistance and causes a poor prognosis in this disease. Therefore, understanding the molecular mechanism of OPN is critical for the treatment and prognosis of NSCLC.

Methods

We used bioinformatics analysis to verify the expression of OPN in normal lung tissues and lung cancer tissues. Then we overexpressed and knocked down OPN in cell lines to detect cell proliferation, migration, invasion, and effects on signaling pathways. Finally, malignant progression and drug resistance induced by OPN were investigated by the wound healing assay, transwell assay, clone formation assay, and Western blot analysis.

Results

We verified that OPN was upregulated in NSCLC tissues, and its overexpression induced NSCLC cell proliferation, migration, and invasion via the mitogen-activated protein kinase (MAPK) pathway. Furthermore, overexpression of OPN reduced the sensitivity of NSCLC cells to cetuximab by upregulating MAPK pathway-related proteins. These results suggested that OPN promoted malignant progression and mediated drug resistance via the MAPK signaling pathway in NSCLC cells.

Conclusion

This study reveals the important role of OPN in NSCLC cells, making it a potential target for improving chemotherapy efficiency in patients with NSCLC.

Oxidative Stress-Induced DNA Damage and Apoptosis in Clove Buds-Treated MCF-7 Cells

In recent decades, several spices have been studied for their potential in the prevention and treatment of cancer. It is documented that spices have antioxidant, anti-inflammatory, immunomodulatory, and anticancer effects. The main mechanisms of spices action included apoptosis induction, proliferation, migration and invasion of tumour inhibition, and sensitization of tumours to radiotherapy and chemotherapy. In this study, the ability of clove buds extract (CBE) to induce oxidative stress, DNA damage, and stress/survival/apoptotic pathways modulation were analysed in MCF-7 cells. We demonstrated that CBE treatment induced intrinsic caspase-dependent cell death associated with increased oxidative stress mediated by oxygen and nitrogen radicals. We showed also the CBE-mediated release of mitochondrial pro-apoptotic factors, signalling of oxidative stress-mediated DNA damage with modulation of cell antioxidant SOD (superoxide dismutase) system, and modulation activity of the Akt, p38 MAPK, JNK and Erk 1/2 pathways.

Compound ammonium glycyrrhizin protects hepatocytes from injury induced by lipopolysaccharide/florfenicol through oxidative stress and a MAPK pathway

Compound ammonium glycyrrhizin (CAG) protects hepatocytes from injury induced by lipopolysaccharide (LPS)/florfenicol (FFC) through a mitochondrial pathway. On this basis, the research was aimed to investigate whether CAG protects hepatocytes from injury induced by LPS/FFC through oxidative stress and the MAPK pathway. For liver injury induced by LPS/FFC, not only CAG can protect hepatocytes and prevent membrane permeability from being increased, but also the activities of ALT and AST were decreased significantly by CAG. Flow cytometry analysis indicated that the apoptosis rate (35.65 ± 2.48%) of LPS/FFC group was significantly higher than that of the control group (8.60 ± 0.32%). CAG (concentration of 0.01 μg/mL, 0.1 μg/mL, 1 μg/mL) significantly decreased the apoptosis rate (23.69 ± 0.54%, 14.92 ± 2.45% and 9.47 ± 1.28%) for the liver injury induced by LPS/FFC. The activities of SOD and GSH were increased with the increased concentration of CAG, and the activity of MDA was decreased with the increased concentration of CAG. All the mRNA and proteins expression levels were increased by LPS/FFC-induced liver injury which associated with the MAPK pathway, and those of the CAG group were decreased with the increased concentration of CAG. And the change of caspase-3 activity was consistent with that of proteins and mRNA. It is suggested that LPS/FFC can induce liver injury through apoptosis and the CAG can protect hepatocytes from injury through the MAPK pathway and oxidative stress.

Low‑intensity pulsed ultrasound promotes apoptosis and inhibits angiogenesis via p38 signaling‑mediated endoplasmic reticulum stress in human endothelial cells

Aberrant increase in angiogenesis contributes to the progression of malignant solid tumors. An alternative anti-angiogenesis therapy is critical for cancer, since the current anti-angiogenesis drugs lack specificity for tumor cells. In the present study, the effects and mechanisms of low-intensity pulsed ultrasound (LIPUS) on human umbilical vein endothelial cells (HUVECs) and human microvascular endothelial cells (HMECs) were investigated, and the therapeutic potential of this technology was assessed. HUVECs and HMECs were treated with LIPUS (0.5 MHz; 210 mW/cm²) for 1 min and cultured for 24 h. Flow cytometry and Cell Counting Kit-8 assays demonstrated that LIPUS treatment at a dose of 210 mW/cm² promoted apoptosis and decreased the viability in HUVECs and HMECs. Real-time cell analysis also revealed that LIPUS did not affect the proliferation or migration of HUVECs. An endothelial cell tube formation assay indicated that LIPUS treatment inhibited the angiogenic ability of HUVECs and HMECs. Furthermore, LIPUS increased the protein levels of the apoptosis-associated cleaved Caspase-3 and decreased the B-cell lymphoma-2 levels. LIPUS increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK), and the levels of endoplasmic reticulum (ER) stress-associated markers, including activating transcription factor-4 (ATF-4) and phosphorylated eukaryotic initiation factor 2α (eIF2α). The p38 inhibitor SB203580 reversed the pro-apoptotic and anti-angiogenic effects of LIPUS in cells. Finally, inhibition of p38 decreased the LIPUS-induced elevation of p-eIF2α and ATF-4 levels. Taken together, these results suggested that LIPUS promoted apoptosis and inhibited angiogenesis in human endothelial cells via the activation of p38 MAPK-mediated ER stress signaling.

Luteolin suppresses tumor proliferation through inducing apoptosis and autophagy via MAPK activation in glioma

Purpose

Glioma is a malignant tumor that originates in the brain and spine and is difficult to be completely removed. Though glioma patients receive active treatment, the survival rate is still poor. Therefore, it is urgent to discover a new medicine to treat glioma patients in order to improve the survival rate. In this study, we explored the anticancer effect and the potential mechanism of luteolin on glioma in vitro.

Materials and methods

Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Fluorescent microscopy and flow cytometry analysis were used to determine the cellular apoptosis. Western blot analysis was performed to explore the changes in protein expression. Quantitative reverse transcription-PCR (qRT-PCR) analysis was utilized to evaluate the expression level of the tumor suppressor miR-124-3p.

Results

CCK-8 assays indicated that luteolin significantly inhibited glioma cell proliferation in a time- and dose-dependent manner. Fluorescent microscopy and flow cytometry analysis confirmed that luteolin induced glioma cell apoptosis. Western blot analysis showed that luteolin induced cellular apoptosis in glioma cells via MAPK activation (JNK, ERK, and p38). Luteolin stimulated the death receptor (FADD) to regulate the apoptosis proteins (Caspase-8, Caspase-3, and PARP). Luteolin increased the expression levels of LC3B II/I and downregulated the level of p62 that promotes cell autophagy. Finally, qRT-PCR confirmed that luteolin upregulated the expression levels of miR-124-3p.

Conclusion

These findings illustrate that luteolin may be a potential drug for glioma treatment.

Notoamide-type alkaloid induced apoptosis and autophagyviaa P38/JNK signaling pathway in hepatocellular carcinoma cells

Eleven notoamides including four new congeners were isolated fromAspergillus ochraceus. Notoamide G inhibited the viability of hepatocellular carcinoma cell lines by regulation of apoptosis and autophagy through P38/JNK signaling pathway.

Deguelin induces apoptosis in colorectal cancer cells by activating the p38 MAPK pathway

Objectives

Deguelin, a rotenoid extracted from Mundulea sericea (Leguminosae), exhibits antitumor effects on several types of human cancers. Due to the limited studies of deguelin on colorectal cancer (CRC), the present study was designed to investigate the antitumor effect of deguelin and to explore the underlying mechanism in CRC.

Materials and methods

Cell viability was assessed by the cell counting kit-8 (CCK-8) assay, and cell apoptosis was determined by the annexin v-propidium iodide staining using flow cytometry and Western blot in CRC cell lines after incubation with deguelin. The antitumor effect of deguelin was further evaluated in tumor xenograft models. Moreover, SB203580, a specific inhibitor of p38 MAPK, was used to confirm the involvement of p38 MAPK pathway in deguelin-induced apoptosis.

Results

Deguelin significantly inhibited cell proliferation and induced apoptosis in CRC cell lines (SW620 and RKO) in a time-dependent and dose-dependent manner. Western blot analysis also showed that the expression of proapoptotic proteins (cleaved caspase 3 and cleaved PARP) was upregulated, while that of antiapoptotic proteins (Bcl-2 and survivin) was downregulated after deguelin treatment in CRC cell lines. Moreover, oral administration of deguelin significantly suppressed tumor growth and induced apoptosis in subcutaneous xenograft mouse models without obvious toxicity. Additionally, Western blot revealed that deguelin-induced apoptosis might be regulated by the p38 MAPK pathway and inhibition of p38 MAPK could attenuate deguelin-induced proliferative inhibition and apoptosis in CRC cells.

Conclusion

Collectively, these results demonstrated that deguelin inhibited CRC cell growth by inducing apoptosis via activation of p38 MAPK pathway.

Accounting for tumor heterogeneity when using CRISPR-Cas9 for cancer progression and drug sensitivity studies

Gene editing protocols often require the use of a subcloning step to isolate successfully edited cells, the behavior of which is then compared to the aggregate parental population and/or other non-edited subclones. Here we demonstrate that the inherent functional heterogeneity present in many cell lines can render these populations inappropriate controls, resulting in erroneous interpretations of experimental findings. We describe a novel CRISPR/Cas9 protocol that incorporates a single-cell cloning step prior to gene editing, allowing for the generation of appropriately matched, functionally equivalent control and edited cell lines. As a proof of concept, we generated matched control and osteopontin-knockout Her2+ and Estrogen receptor-negative murine mammary carcinoma cell lines and demonstrated that the osteopontin-knockout cell lines exhibit the expected biological phenotypes, including unaffected primary tumor growth kinetics and reduced metastatic outgrowth in female FVB mice. Using these matched cell lines, we discovered that osteopontin-knockout mammary tumors were more sensitive than control tumors to chemotherapy in vivo. Our results demonstrate that heterogeneity must be considered during experimental design when utilizing gene editing protocols and provide a solution to account for it.

Isorhamnetin: A hepatoprotective flavonoid inhibits apoptosis and autophagy via P38/PPAR-α pathway in mice

Isorhamnetin, a flavonoid compound extracted from plants' fruit or leaves, like sea buckthorn (Hippophae rhamnoides L.), has many biological functions, including anti-tumor, anti-oxidant and anti-inflammatory effect. The present study is in order to explore the hepatoprotective effect of isorhamnetin on concanavalin A (ConA)-induced acute fulminant hepatitis and the underlying mechanism. Mice were injected with ConA (25 mg/kg) to induce acute fulminant hepatitis, three doses of isorhamnetin (10/30/90 mg/kg) was intraperitoneally administrated about 1 h previously. The serum and liver tissues were harvested at 2, 8, and 24 h after ConA injection. The levels of serum liver enzymes and proinflammatory cytokines were significantly reduced in isorhamnetin administration groups. Besides, isorhamnetin improved pathological damage. Furthermore, isorhamnetin affected P38/PPAR-α pathway, and subsequently regulated the expression of apoptosis and autophagy related proteins. The present study investigated that isorhamnetin inhibits apoptosis and autophagy via P38/PPAR-α pathway in mice.

The role of osteopontin in the progression of solid organ tumour

Osteopontin (OPN) is a bone sialoprotein involved in osteoclast attachment to mineralised bone matrix, as well as being a bone matrix protein, OPN is also a versatile protein that acts on various receptors which are associated with different signalling pathways implicated in cancer. OPN mediates various biological events involving the immune system and the vascular system; the protein plays a role in processes such as immune response, cell adhesion and migration, and tumorigenesis. This review discusses the potential role of OPN in tumour cell proliferation, angiogenesis and metastasis, as well as the molecular mechanisms involved in these processes in different cancers, including brain, lung, kidney, liver, bladder, breast, oesophageal, gastric, colon, pancreatic, prostate and ovarian cancers. The understanding of OPN’s role in tumour development and progression could potentially influence cancer therapy and contribute to the development of novel anti-tumour treatments.

Alisertib promotes apoptosis and autophagy in melanoma through p38 MAPK-mediated aurora a signaling

We investigated the efficacy of Alisertib (ALS), a selective Aurora kinase A (AURKA) inhibitor, in melanoma. We found that ALS exerts anti-proliferative, pro-apoptotic, and pro-autophagic effects on A375 and skmel-5 melanoma cells by inhibiting p38 MAPK signaling. SB202190, a p38 MAPK-selective inhibitor, enhanced ALS-induced apoptosis and autophagy in both cell lines. ALS induced cell cycle arrest in melanoma cells through activation of the p53/p21/cyclin B1 pathway. Knockdown of p38 MAPK enhanced ALS-induced apoptosis and reduced ALS-induced autophagy. Inhibition of autophagy sensitized melanoma cells to ALS-induced apoptosis. These data indicate ALS is a potential therapeutic agent for melanoma.

Unfavorable effect of calcitriol and its low-calcemic analogs on metastasis of 4T1 mouse mammary gland cancer

Low vitamin D status is considered as a risk factor for breast cancer and has prognostic significance. Furthermore, vitamin D deficiency increases after adjuvant cancer therapy, which alters bone metabolism increasing the risk of osteoporosis. It is now postulated that vitamin D supplementation in breast cancer treatment delays the recurrence of cancer thereby extending survival. We evaluated the impact of calcitriol and its low-calcemic analogs, PRI-2191 and PRI-2205, on the tumor growth, angiogenesis, and metastasis of 4T1 mouse mammary gland cancer. Gene expression analysis related to cancer invasion/metastasis, real-time PCR, ELISA, western blotting, and histochemical studies were performed. In vitro studies were conducted to compare the effects of calcitriol and its analogs on 4T1 and 67NR cell proliferation and expression of selected proteins. Calcitriol and its analogs increased lung metastasis without influencing the growth of primary tumor. The levels of plasma 17β-estradiol and transforming growth factor β (TGFβ) were found to be elevated after treatment. Moreover, the results showed that tumor blood perfusion improved and osteopontin (OPN) levels increased, whereas vascular endothelial growth factor (VEGF) and TGFβ levels decreased in tumors from treated mice. All the studied treatments resulted in increased collagen content in the tumor tissue in the early step of tumor progression, and calcitriol caused an increase in collagen content in lung tissue. In addition, in vitro proliferation of 4T1 tumor cells was not found to be affected by calcitriol or its analogs in contrast to non-metastatic 67NR cells. Calcitriol and its analogs enhanced the metastatic potential of 4T1 mouse mammary gland cancer by inducing the secretion of OPN probably via host cells. In addition, OPN tumor overexpression prevailed over the decreasing tumor TGFβ level and blood vessel normalization via tumor VEGF deprivation induced by calcitriol and its analogs. Moreover, the increased plasma TGFβ and 17β-estradiol levels contributed to the facilitation of metastatic process.

Malformin A1 treatment alters invasive and oncogenic phenotypes of human colorectal cancer cells through stimulation of the p38 signaling pathway

Malformin A1 (MA1), a cyclic pentapeptide isolated from Aspergillus niger, has been found to possess a range of bioactive properties including antibacterial activity. However, it is unclear whether MA1 exerts an anticancer effect or not. In this study, we conducted in vitro experiments to investigate its anticancer properties in human colorectal cancer cells. The effect of MA1 on human colorectal cancer cells, SW480 and DKO1, was examined by the WST-1 cell viability assay, inverted microscopy, 5-bromo-2-deoxyuridine (BrdU) incorporation, flow cytometry, DNA fragmentation, wound healing, Transwell assays, and western blotting. MA1 treatment showed potent cytotoxic activities on human colorectal cancer cells. MA1 treatment induced apoptosis by activating the poly(ADP-ribose) polymerase (PARP), caspase‑3, -7, and -9. MA1 treatment led to the increase in p53 upregulated modulator of apoptosis (PUMA) and the decrease in X-linked inhibitor of apoptosis protein (XIAP) and Survivin. In addition, MA1 treatment induced cell cycle arrest in the sub-G1 phase. The pan-caspase inhibitor, Z‑VAD‑FMK, attenuated these MA1-induced apoptotic effects on human colorectal cancer cells. Moreover, MA1 treatment suppressed tumor cell migration and invasion. The phosphorylation level of p38 was upregulated by MA1 treatment, and the inhibitor of p38, SB203580, attenuated the MA1-induced p38 phosphorylation as well as caspase‑3 and PARP activation. These results indicate that MA1 treatment alters invasive and oncogenic phenotypes of human colorectal cancer cells through the stimulation of the p38 signaling pathway.

Osteopontin induces autophagy to promote chemo-resistance in human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a major health burden worldwide for its high incidence and mortality. Osteopontin (OPN) is a chemokine-like, matricellular phosphoglycoprotein whose expression is elevated in various types of cancer including HCC. OPN has been shown to be involved in tumorigenesis, chemo-resistance, metastasis and sustaining stem-like properties of cancer cells. Autophagy is a cellular process by which cytoplasmic components are degraded and recycled for maintaining cellular homeostasis. There is increasing evidence supports that autophagy plays a critical role for stem-like properties and chemo-resistance of cancer cells. However, the relationship between OPN and autophagy in maintaining cancer stem-like properties and chemo-resistance is yet to be clarified. Herein, we found that secreted OPN induced autophagy via binding with its receptor integrin αvβ3 and sustaining FoxO3a stability. OPN-elicited autophagy could promote cancer cell survival and resistance to chemotherapy drugs, as well as stem-like properties. Our findings indicated that OPN was capable of promoting chemo-resistance of HCCs via autophagy, which might provide a new strategy for the treatment of HCC.

Osteopontin splice variants are differential predictors of breast cancer treatment responses

Background

Osteopontin is a marker for breast cancer progression, which in previous studies has also been associated with resistance to certain anti-cancer therapies. It is not known which splice variants may mediate treatment resistance.

Methods

Here we analyze the association of osteopontin variant expression before treatment, differentiated according to immunohistochemistry with antibodies to exon 4 and to the osteopontin-c splice junction respectively, with the ensuing therapy responses in 119 Polish breast cancer patients who presented between 1995 and 2008.

Results

We found from Cox hazard models, logrank test and Wilcoxon test that osteopontin exon 4 was associated with a favorable response to tamoxifen, but a poor response to chemotherapy with CMF (cyclophosphamide, methotrexate, fluorouracil). Osteopontin-c is prognostic, but falls short of being a significant predictor for sensitivity to treatment.

Conclusions

The addition of osteopontin splice variant immunohistochemistry to standard pathology work-ups has the potential to aid decision making in breast cancer treatment.

Chemosensitizing effect of podophyllotoxin acetate on topoisomerase inhibitors leads to synergistic enhancement of lung cancer cell apoptosis

Podophyllotoxin acetate (PA) acts as a radiosensitizer against non-small cell lung cancer (NSCLC) in vitro and in vivo. In this study, we examined its potential role as a chemosensitizer in conjunction with the topoisomerase inhibitors etoposide (Eto) and camptothecin (Cpt). The effects of combinations of PA and Eto/Cpt were examined with CompuSyn software in two NSCLC cell lines, A549 and NCI-H1299. Combination index (CI) values indicated synergistic effects of PA and the topoisomerase inhibitors. The intracellular mechanism underlying synergism was further determined using propidium iodide uptake, immunoblotting and electrophoretic mobility shift assay (EMSA). Combination of PA with Eto/Cpt promoted disruption of the dynamics of actin filaments, leading to subsequent enhancement of apoptotic cell death via induction of caspase-3, -8, and -9, accompanied by increased phosphorylation of p38. Conversely, suppression of p38 phosphorylation blocked the apoptotic effect of the drug combinations. Notably, CREB-1, a transcription factor, was constitutively activated in both cell types, and synergistically inhibited upon combination treatment. Our results collectively indicate that PA functions as a chemosensitizer by enhancing apoptosis through activation of the p38/caspase axis and suppression of CREB-1.

Tumor-extracellular matrix interactions: Identification of tools associated with breast cancer progression

Several evidences support the concept that cancer development and progression are not entirely cancer cell-autonomous processes, but may be influenced, and possibly driven, by cross-talk between cancer cells and the surrounding microenvironment in which, besides immune cells, stromal cells and extracellular matrix (ECM) play a major role in regulating distinct biologic processes. Stroma and ECM-related signatures proved to influence breast cancer progression, and to contribute to the identification of tumor phenotypes resistant to cytotoxic and hormonal treatments. The possible clinical implications of the interplay between tumor cells and the microenvironment, with special reference to ECM remodelling, will be discussed in this review.

Osteopontin Regulates VEGFA and ICAM-1 mRNA Expression in Breast Carcinoma

OBJECTIVES

To analyze the regulatory role of osteopontin on biomarkers associated with cell survival, invasiveness, and angiogenesis mechanisms in a clinical series and breast cancer cell lines.

METHODS

We analyzed by quantitative real-time polymerase chain reaction the messenger RNA (mRNA) expression of osteopontin, Bcl2, intercellular adhesion molecule 1 (ICAM-1), and vascular endothelial growth factor A (VEGFA) in several breast cancer cell lines and in 148 breast carcinomas classified into intrinsic subtypes.

RESULTS

We found coexpression of osteopontin, Bcl2, ICAM-1, and VEGFA in triple-negative MDA-MB-468 and MDA-MB-231 cell lines. Furthermore, osteopontin silencing by small interfering RNA inhibited ICAM-1 and VEGFA expression and cell proliferation in MDA-MB-468 cells. In breast cancer specimens, we found a positive correlation between osteopontin, ICAM-1, and VEGFA mRNA expression, especially in triple-negative/basal-like tumors. Among patients with osteopontin-overexpressing tumors, VEGFA remained an independent prognostic indicator for recurrence (hazard ratio, 2.95; 95% confidence interval [CI], 1.48-5.87; P = .002) and death (hazard ratio, 3.25; 95% CI, 1.48-7.11; P = .003) (multivariate analysis, Cox regression).

CONCLUSIONS

Our results support that osteopontin regulates ICAM-1 and VEGFA expression mainly in triple-negative/basal-like breast carcinomas, suggesting a relevant role in the pathogenesis and tumor progression of this molecular subtype. Moreover, VEGFA mRNA levels showed an independent prognostic value in patients with breast cancer.

Comparison of cantharidin toxicity in breast cancer cells to two common chemotherapeutics

As part of a larger study synthesizing a more directed form of chemotherapy, we have begun to assess the efficacy of different potential toxins that could be delivered locally rather than systemically. In doing so, we hope to reduce the systemic side effects commonly observed, while maintaining a high level of toxicity and eliminating the need for metabolic alterations. In a search for this more efficient method for killing cancerous cells, we have begun studying cantharidin, a toxin used in traditional Chinese medicine, as a potential chemotherapeutic. Using an MTT cell viability assay, the toxicity of cantharidin was compared to both cyclophosphamide and paclitaxel in three different breast cancer cell lines: MCF-7, MDA-MB-231, and SK-BR-3. Increasing the concentration of chemotherapy drugs did decrease cell viability in all cell lines when cantharidin and cyclophosphamide were applied; however differences for paclitaxel were cell-specific. Additionally, cantharidin exhibited the highest decrease in cell viability regardless of cell type, indicating it may be a much more potent and less specific chemotherapeutic. These results will help us move forward in developing a potentially more potent treatment for breast cancer that might eliminate the need for subtype-specific treatments.

Role of osteopontin in the pathophysiology of cancer

Osteopontin (OPN) is a multifunctional cytokine that impacts cell proliferation, survival, drug resistance, invasion, and stem like behavior. Due to its critical involvement in regulating cellular functions, its aberrant expression and/or splicing is functionally responsible for undesirable alterations in disease pathologies, specifically cancer. It is implicated in promoting invasive and metastatic progression of many carcinomas. Due to its autocrine and paracrine activities OPN has been shown to be a crucial mediator of cellular cross talk and an influential factor in the tumor microenvironment. OPN has been implicated as a prognostic and diagnostic marker for several cancer types. It has also been explored as a possible target for treatment. In this article we hope to provide a broad perspective on the importance of OPN in the pathophysiology of cancer.

Extracellular matrix components in breast cancer progression and metastasis

The extracellular matrix (ECM) is composed of highly variable and dynamic components that regulate cell behavior. The protein composition and physical properties of the ECM govern cell fate through biochemical and biomechanical mechanisms. This requires a carefully orchestrated and thorough regulation considering that a disturbed ECM can have serious consequences and lead to pathological conditions like cancer. In breast cancer, many ECM proteins are significantly deregulated and specific matrix components promote tumor progression and metastatic spread. Intriguingly, several ECM proteins that are associated with breast cancer development, overlap substantially with a group of ECM proteins induced during the state of tissue remodeling such as mammary gland involution. Fibrillar collagens, fibronectin, hyaluronan and matricellular proteins are matrix components that are common to both involution and cancer. Moreover, some of these proteins have in recent years been identified as important constituents of metastatic niches in breast cancer. In addition, specific ECM molecules, their receptors or enzymatic modifiers are significantly involved in resistance to therapeutic intervention. Further analysis of these ECM proteins and the downstream ECM mediated signaling pathways may provide a range of possibilities to identify druggable targets against advanced breast cancer.

Osteopontin is associated with decreased apoptosis and αv integrin expression in lung adenocarcinoma

Osteopontin (OPN) is a glycoprotein involved in invasion, progression and metastasis of many carcinomas. It contains several functional domains including binding sites for αv integrins, cell surface molecules playing a major role in mediating cell migration and adhesion. The aim of the study was to evaluate the expression of osteopontin in human non-small cell lung cancer (NSCLC) and to determine its possible prognostic significance as well as relation to apoptosis and αv integrin expression. We analyzed 111 surgically resected NSCLC for immunohistochemical expression of OPN and αv integrin. OPN expression was compared to apoptotic rate and clinicopathological parameters such as tumor size, histological grade, lymph node status, pT, and TNM stage. Apoptotic rate was measured by TUNEL staining method. OPN expression in NSCLC was significantly higher in lung adenocarcinomas (AC) then in squamous cell carcinomas (p<0.001). There was no correlation between OPN expression and clinicopathological parameters. The level of OPN expression in AC was associated with decreased apoptotic activity of tumor cells (p=0.006), and correlated with αv integrin expression (p=0.048), particularly in low stage tumors (p=0.013). Prolonged tumor cell survival in lung AC due to OPN and αv integrin overexpression may have an impact on tumor progression and resistance to therapy.

p38 and JNK MAPK pathways control the balance of apoptosis and autophagy in response to chemotherapeutic agents

The Mitogen Activated Protein Kinase (MAPK) signaling plays a critical role in the outcome and the sensitivity to anticancer therapies. Activated MAPK can transmit extracellular signals to regulate cell growth, proliferation, differentiation, migration, apoptosis and so on. Apoptosis as well as macroautophagy (hereafter referred to as autophagy) can be induced by extracellular stimuli such the treatment of chemotherapeutic agents, resulting in different cell response to these drugs. However, the molecular mechanisms mediating these two cellular processes remain largely unknown. Recently, several studies provide new insights into p38 and JNK MAPK pathways function in the control of the balance of autophagy and apoptosis in response to genotoxic stress. Our increased understanding of the role of p38 and JNK MAPK pathways in regulating the balance of autophagy and apoptosis will hopefully provide prospective strategies for cancer therapy.

Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells

ERα17p is a peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ERα) and initially found to interfere with ERα-related calmodulin binding. ERα17p was subsequently found to elicit estrogenic responses in E2-deprived ERα-positive breast cancer cells, increasing proliferation and ERE-dependent gene transcription. Surprisingly, in E2-supplemented media, ERα17p-induced apoptosis and modified the actin network, influencing cell motility. Here, we report that ERα17p internalizes in breast cancer cells (T47D, MDA-MB-231, SKBR3) and induces a massive early (3 h) transcriptional activity. Remarkably, about 75% of significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ERα17p. The different ER spectra of the used cell lines allowed us to identify a specific ERα17p signature related to ERα as well as its variant ERα36. With respect to ERα, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ERα36, it mainly triggers inhibitory actions on inflammation. This is the first work reporting a detailed ERα36-specific transcriptional signature. In addition, we report that ERα17p-induced transcripts related to apoptosis and actin modifying effects of the peptide are independent from its estrogen receptor(s)-related actions. We discuss our findings in view of the potential use of ERα17p as a selective peptidomimetic estrogen receptor modulator (PERM).

Enhanced RAD21 cohesin expression confers poor prognosis in BRCA2 and BRCAX, but not BRCA1 familial breast cancers

INTRODUCTION

The RAD21 gene encodes a key component of the cohesin complex, which is essential for chromosome segregation, and together with BRCA1 and BRCA2, for high-fidelity DNA repair by homologous recombination. Although its expression correlates with early relapse and treatment resistance in sporadic breast cancers, it is unclear whether familial breast cancers behave in a similar manner.

METHODS

We performed an immunohistochemical analysis of RAD21 expression in a cohort of 94 familial breast cancers (28 BRCA1, 27 BRCA2, and 39 BRCAX) and correlated these data with genotype and clinicopathologic parameters, including survival. In these cancers, we also correlated RAD21 expression with genomic expression profiling and gene copy-number changes and miRNAs predicted to target RAD21.

RESULTS

No significant differences in nuclear RAD21 expression were observed between BRCA1 (12 (43%) of 28), BRCA2 (12 (44%) of 27), and BRCAX cancers (12 (33%) of 39 (p = 0.598). No correlation was found between RAD21 expression and grade, size, or lymph node, ER, or HER2 status (all P > 0.05). As for sporadic breast cancers, RAD21 expression correlated with shorter survival in grade 3 (P = 0.009) and but not in grade 1 (P = 0.065) or 2 cancers (P = 0.090). Expression of RAD21 correlated with poorer survival in patients treated with chemotherapy (P = 0.036) but not with hormonal therapy (P = 0.881). RAD21 expression correlated with shorter survival in BRCA2 (P = 0.006) and BRCAX (P = 0.008), but not BRCA1 cancers (P = 0.713). Changes in RAD21 mRNA were reflected by genomic changes in DNA copy number (P < 0.001) and by RAD21 protein expression, as assessed with immunohistochemistry (P = 0.047). High RAD21 expression was associated with genomic instability, as assessed by the total number of base pairs affected by genomic change (P = 0.048). Of 15 miRNAs predicted to target RAD21, mir-299-5p inversely correlated with RAD21 expression (P = 0.002).

CONCLUSIONS

Potential use of RAD21 as a predictive and prognostic marker in familial breast cancers is hence feasible and may therefore take into account the patient's BRCA1/2 mutation status.