Salvianolic acid A reverses paclitaxel resistance in human breast cancer MCF-7 cells via targeting the expression of transgelin 2 and attenuating PI3 K/Akt pathway

Transgelin-2, a novel cancer stem cell-related biomarker, is a diagnostic and therapeutic target for biliary tract cancer

BACKGROUND

Biliary tract cancer (BTC) is a relatively rare but aggressive gastrointestinal cancer with a high mortality rate. Cancer stem cell (CSC) populations play crucial roles in tumor biology and are responsible for the low response to anti-cancer treatment and the high recurrence rate. This study investigated the role of Transgelin-2 (TAGLN2), overexpressed in CSC in BTC cells, and analyzed its expression in patient tissues and serum to identify potential new targets for BTC.

METHODS

TAGLN2 expression was suppressed by small-interfering or short hairpin RNAs, and its effects on tumor biology were assessed in several BTC cell lines. Furthermore, the effects of TAGLN2 silencing on gemcitabine-resistant BTC cells, differentially expressed genes, proteins, and sensitivity to therapeutics or radiation were assessed. TAGLN2 expression was also assessed using western blotting and immunohistochemistry in samples obtained from patients with BTC to validate its clinical application.

RESULTS

Suppression of TAGLN2 in BTC cell lines decreased cell proliferation, migration, invasion, and tumor size, in addition to a reduction in CSC features, including clonogenicity, radioresistance, and chemoresistance. TAGLN2 was highly expressed in BTC tissues, especially in cancer-associated fibroblasts in the stroma. Patients with a low stromal immunohistochemical index had prolonged disease-free survival compared to those with a high stromal immunohistochemical index (11.5 vs. 7.4 months, P = 0.013). TAGLN2 expression was higher in the plasma of patients with BTC than that in those with benign diseases. TAGLN2 had a higher area under the curve (0.901) than CA19-9, a validated tumor biomarker (0.799; P < 0.001).

CONCLUSION

TAGLN2 plays a critical role in promoting BTC cell growth and motility and is involved in regulating BTC stemness. Silencing TAGLN2 expression enhanced cell sensitivity to radiation and chemotherapeutic drugs. The expression of TAGLN2 in patient tissue and plasma suggests its potential to serve as a secretory biomarker for BTC. Overall, targeting TAGLN2 could be an appropriate therapeutic strategy against advanced cancer following chemotherapy failure.

Adjuvant role of Salvia miltiorrhiza bunge in cancer chemotherapy: A review of its bioactive components, health-promotion effect and mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Chemotherapy is a common cancer treatment strategy. However, its effectiveness is constrained by toxicity and adverse effects. The Lamiaceae herb Salvia miltiorrhiza Bunge has a long history of therapeutic use in the treatment of blood stasis illnesses, which are believed by traditional Chinese medicine to be connected to cancer.

AIM OF THE STUDY

This review summarized the common toxicity of chemotherapy and the potential chemo-adjuvant effect and mechanisms of active ingredients from S. miltiorrhiza, hoping to provide valuable information for the development and application of S. miltiorrhiza resources.

MATERIALS AND METHODS

The literatures were retrieved from PubMed, Web of Science, Baidu Scholar and Google Scholar databases from 2002 to 2022. The inclusion criteria were studies reporting that S. miltiorrhiza or its constituents enhanced the efficiency of chemotherapy drugs or reduced the side effects.

RESULTS

Salvianolic acid A, salvianolic acid B, salvianolic acid C, rosmarinic acid, tanshinone I, tanshinone IIA, cryptotanshinone, dihydrotanshinone I and miltirone are the primary adjuvant chemotherapy components of S. miltiorrhiza. The mechanisms mainly involve inhibiting proliferation, metastasis, and angiogenesis, inducing apoptosis, regulating autophagy and tumor microenvironment. In addition, they also improve chemotherapy drug-induced side effects.

CONCLUSIONS

The bioactive compounds of S. miltiorrhiza are shown to inhibit proliferation, metastasis, and angiogenesis, induce apoptosis and autophagy, regulate immunity and tumor microenvironment when combined with chemotherapy drugs. However, further clinical studies are required to validate the current studies.

Hormonal and Genetic Regulatory Events in Breast Cancer and Its Therapeutics: Importance of the Steroidogenic Acute Regulatory Protein

Estrogen promotes the development and survival of the majority of breast cancers (BCs). Aromatase is the rate-limiting enzyme in estrogen biosynthesis, and it is immensely expressed in both cancerous and non-cancerous breast tissues. Endocrine therapy based on estrogen blockade, by aromatase inhibitors, has been the mainstay of BC treatment in post-menopausal women; however, resistance to hormone therapy is the leading cause of cancer death. An improved understanding of the molecular underpinnings is the key to develop therapeutic strategies for countering the most prevalent hormone receptor positive BCs. Of note, cholesterol is the precursor of all steroid hormones that are synthesized in a variety of tissues and play crucial roles in diverse processes, ranging from organogenesis to homeostasis to carcinogenesis. The rate-limiting step in steroid biosynthesis is the transport of cholesterol from the outer to the inner mitochondrial membrane, a process that is primarily mediated by the steroidogenic acute regulatory (StAR) protein. Advances in genomic and proteomic technologies have revealed a dynamic link between histone deacetylases (HDACs) and StAR, aromatase, and estrogen regulation. We were the first to report that StAR is abundantly expressed, along with large amounts of 17β-estradiol (E2), in hormone-dependent, but not hormone-independent, BCs, in which StAR was also identified as a novel acetylated protein. Our in-silico analyses of The Cancer Genome Atlas (TCGA) datasets, for StAR and steroidogenic enzyme genes, revealed an inverse correlation between the amplification of the StAR gene and the poor survival of BC patients. Additionally, we reported that a number of HDAC inhibitors, by altering StAR acetylation patterns, repress E2 synthesis in hormone-sensitive BC cells. This review highlights the current understanding of molecular pathogenesis of BCs, especially for luminal subtypes, and their therapeutics, underlining that StAR could serve not only as a prognostic marker, but also as a therapeutic candidate, in the prevention and treatment of this life-threatening disease.

Salvia miltiorrhiza in Breast Cancer Treatment: A Review of Its Phytochemistry, Derivatives, Nanoparticles, and Potential Mechanisms

Breast cancer is one of the most deadly malignancies in women worldwide. Salvia miltiorrhiza, a perennial plant that belongs to the genus Salvia, has long been used in the management of cardiovascular and cerebrovascular diseases. The main anti-breast cancer constituents in S. miltiorrhiza are liposoluble tanshinones including dihydrotanshinone I, tanshinone I, tanshinone IIA, and cryptotanshinone, and water-soluble phenolic acids represented by salvianolic acid A, salvianolic acid B, salvianolic acid C, and rosmarinic acid. These active components have potent efficacy on breast cancer in vitro and in vivo. The mechanisms mainly include induction of apoptosis, autophagy and cell cycle arrest, anti-metastasis, formation of cancer stem cells, and potentiation of antitumor immunity. This review summarized the main bioactive constituents of S. miltiorrhiza and their derivatives or nanoparticles that possess anti-breast cancer activity. Besides, the synergistic combination with other drugs and the underlying molecular mechanisms were also summarized to provide a reference for future research on S. miltiorrhiza for breast cancer treatment.

The Epithelial and Stromal Immune Microenvironment in Gastric Cancer: A Comprehensive Analysis Reveals Prognostic Factors with Digital Cytometry

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Tumor heterogeneity continues to confound researchers' understanding of tumor growth and the development of an effective therapy. Digital cytometry allows interpretation of heterogeneous bulk tissue transcriptomes at the cellular level. We built a novel signature matrix to dissect epithelium and stroma signals using a scRNA-seq data set (GSE134520) for GC and then applied cell mixture deconvolution to estimate diverse epithelial, stromal, and immune cell proportions from bulk transcriptome data in four independent GC cohorts (GSE62254, GSE15459, GSE84437, and TCGA-STAD) from the GEO and TCGA databases. Robust computational methods were applied to identify strong prognostic factors for GC. We identified an EMEC population whose proportions were significantly higher in patients with stage I cancer than other stages, and it was predominantly present in tumor samples but not typically found in normal samples. We found that the ratio of EMECs to stromal cells and the ratio of adaptive T cells to monocytes were the most significant prognostic factors within the non-immune and immune factors, respectively. The STEM score, which unifies these two prognostic factors, was an independent prognostic factor of overall survival (HR = 0.92, 95% CI = 0.89-0.94, p=2.05×10-9). The entire GC cohort was stratified into three risk groups (high-, moderate-, and low-risk), which yielded incremental survival times (p<0.0001). For stage III disease, patients in the moderate- and low-risk groups experienced better survival benefits from radiation therapy ((HR = 0.16, 95% CI = 0.06-0.4, p<0.0001), whereas those in the high-risk group did not (HR = 0.49, 95% CI = 0.14-1.72, p=0.25). We concluded that the STEM score is a promising prognostic factor for gastric cancer.

Targeting Autophagy with Natural Products as a Potential Therapeutic Approach for Cancer

Macro-autophagy (autophagy) is a highly conserved eukaryotic intracellular process of self-digestion caused by lysosomes on demand, which is upregulated as a survival strategy upon exposure to various stressors, such as metabolic insults, cytotoxic drugs, and alcohol abuse. Paradoxically, autophagy dysfunction also contributes to cancer and aging. It is well known that regulating autophagy by targeting specific regulatory molecules in its machinery can modulate multiple disease processes. Therefore, autophagy represents a significant pharmacological target for drug development and therapeutic interventions in various diseases, including cancers. According to the framework of autophagy, the suppression or induction of autophagy can exert therapeutic properties through the promotion of cell death or cell survival, which are the two main events targeted by cancer therapies. Remarkably, natural products have attracted attention in the anticancer drug discovery field, because they are biologically friendly and have potential therapeutic effects. In this review, we summarize the up-to-date knowledge regarding natural products that can modulate autophagy in various cancers. These findings will provide a new position to exploit more natural compounds as potential novel anticancer drugs and will lead to a better understanding of molecular pathways by targeting the various autophagy stages of upcoming cancer therapeutics.

Transgelin-2: A Double-Edged Sword in Immunity and Cancer Metastasis

Transgelin-2, a small actin-binding protein, is the only transgelin family member expressed in immune cells. In T and B lymphocytes, transgelin-2 is constitutively expressed, but in antigen-presenting cells, it is significantly upregulated upon lipopolysaccharide stimulation. Transgelin-2 acts as a molecular staple to stabilize the actin cytoskeleton, and it competes with cofilin to bind filamentous (F)-actin. This action may enable immune synapse stabilization during T-cell interaction with cognate antigen-presenting cells. Furthermore, transgelin-2 blocks Arp2/3 complex-nucleated actin branching, which is presumably related to small filopodia formation, enhanced phagocytic function, and antigen presentation. Overall, transgelin-2 is an essential part of the molecular armament required for host defense against neoplasms and infectious diseases. However, transgelin-2 acts as a double-edged sword, as its expression is also essential for a wide range of tumor development, including drug resistance and metastasis. Thus, targeting transgelin-2 can also have a therapeutic advantage for cancer treatment; selectively suppressing transgelin-2 expression may prevent multidrug resistance in cancer chemotherapy. Here, we review newly discovered molecular characteristics of transgelin-2 and discuss clinical applications for cancer and immunotherapy.

Therapeutic strategies to overcome taxane resistance in cancer

One of the primary causes of attenuated or loss of efficacy of cancer chemotherapy is the emergence of multidrug resistance (MDR). Numerous studies have been published regarding potential approaches to reverse resistance to taxanes, including paclitaxel (PTX) and docetaxel, which represent one of the most important classes of anticancer drugs. Since 1984, following the FDA approval of paclitaxel for the treatment of advanced ovarian carcinoma, taxanes have been extensively used as drugs that target tumor microtubules. Taxanes, have been shown to affect an array of oncogenic signaling pathways and have potent cytotoxic efficacy. However, the clinical success of these drugs has been restricted by the emergence of cancer cell resistance, primarily caused by the overexpression of MDR efflux transporters or by microtubule alterations. In vitro and in vivo studies indicate that the mechanisms underlying the resistance to PTX and docetaxel are primarily due to alterations in α-tubulin and β-tubulin. Moreover, resistance to PTX and docetaxel results from: 1) alterations in microtubule-protein interactions, including microtubule-associated protein 4, stathmin, centriole, cilia, spindle-associated protein, and kinesins; 2) alterations in the expression and activity of multidrug efflux transporters of the ABC superfamily including P-glycoprotein (P-gp/ABCB1); 3) overexpression of anti-apoptotic proteins or inhibition of apoptotic proteins and tumor-suppressor proteins, as well as 4) modulation of signal transduction pathways associated with the activity of several cytokines, chemokines and transcription factors. In this review, we discuss the abovementioned molecular mechanisms and their role in mediating cancer chemoresistance to PTX and docetaxel. We provide a detailed analysis of both in vitro and in vivo experimental data and describe the application of these findings to therapeutic practice. The current review also discusses the efficacy of different pharmacological modulations to achieve reversal of PTX resistance. The therapeutic roles of several novel compounds, as well as herbal formulations, are also discussed. Among them, many structural derivatives had efficacy against the MDR phenotype by either suppressing MDR or increasing the cytotoxic efficacy compared to the parental drugs, or both. Natural products functioning as MDR chemosensitizers offer novel treatment strategies in patients with chemoresistant cancers by attenuating MDR and increasing chemotherapy efficacy. We broadly discuss the roles of inhibitors of P-gp and other efflux pumps, in the reversal of PTX and docetaxel resistance in cancer cells and the significance of using a nanomedicine delivery system in this context. Thus, a better understanding of the molecular mechanisms mediating the reversal of drug resistance, combined with drug efficacy and the application of target-based inhibition or specific drug delivery, could signal a new era in modern medicine that would limit the pathological consequences of MDR in cancer patients.

Salvianolic acid A increases the accumulation of doxorubicin in brain tumors through Caveolae endocytosis

Brain glioma is one of the most common brain tumors in the central nervous system (CNS). The blood-brain tumor barrier (BTB) restricts the delivery of anti-tumor drugs into tumor tissue in the brain. Therefore, improving the transportation of antineoplastic drugs across the BTB is essential to ameliorate treatment of brain tumors. The present study was performed to explore the effect and mechanism of salvianolic acid A (Sal A) on transportation of doxorubicin (Dox) across the BTB in vivo and in vitro. By creating a brain C6 glioma model in rats, we demonstrated that Sal A significantly increased the level of Dox in brain tumor tissue as shown by liquid chromatograph mass spectrometry. Interestingly, we found that Sal A increased transendothelial electrical resistance (TEER) values of the BTB and decreased the permeability of FITC-Dextran (4kD) across the BTB in vitro. Furthermore, the expression of tight junction proteins (TJs) in glioma endothelial cells (GECs) and brain tumor microvessels were also increased, suggesting that Sal A enhanced delivery of Dox across the BTB independent of the paracellular pathway. Next, we detected that Sal A had an effect on transcellular transport of compounds across the BTB. The accumulation of FITC-labeled bovine serum albumin (FITC-BSA) was significantly increased in GECs after treatment with Sal A (10 μM) for 6h, which was inhibited after pre-treatment with methyl-β-cyclodextrin (MβCD) for 30 min. The increased delivery of Dox across the BTB was also reduced after treatment with MβCD. In addition, phosphorylation levels of protein kinase B (PKB) and tyrosine protein kinase-Src family (Src) were increased in the Sal A treatment group. Sal A up-regulated the expression level of the phosphorylation of Caveolin-1 (pCaveolin-1), and this effect was reversed by a PKB or Src inhibitor. Taken together, our study showed for the first time that Sal A facilitated the delivery of antitumor drugs into brain tumor tissues by targeting the PKB/Src/Caveolin-1 signaling pathway.

Salvianolic acid A suppresses MMP-2 expression and restrains cancer cell invasion through ERK signaling in human nasopharyngeal carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge, as known as Danshen, has used for the prevention and treatment of cardiovascular diseases clinically and anti-cancer activities. Salvianolic acid A (SAA), one of the most abundant ingredients, hydrophilic derivatives of Salvia miltiorrhiza Bunge, exerts a variety of pharmacological actions, such as anti-oxidative, anti-inflammatory and anti-cancer activities. However, the impact of SAA on nasopharyngeal carcinoma (NPC) invasion and metastasis remains unexplored.

AIM OF THE STUDY

To investigate the potential of SAA to prevent migration and invasion on NPC cell.

MATERIALS AND METHODS

MTT assay and Boyden chamber assay were performed to determine cell proliferation, migration and invasion abilities, respectively. The activity and protein expression of matrix metalloproteinase-2 (MMP-2) were determined by gelatin zymography and western blotting.

RESULTS

Here, we showed that SAA considerably suppressed the migrative and invasive activity of human NPC cells but not rendered cytotoxicity. In SAA-treated NPC cells, the activity and expression of matrix metalloproteinase-2 (MMP-2), a key regulator of cancer cell invasion, were reduced. Additionally, the presence of high concentrations of SAA dramatically abolished the activation of focal adhesion kinase (FAK) and moderately inhibited the phosphorylation of Src and ERK in NPC cells.

CONCLUSIONS

Our results demonstrated that SAA inhibited the migration and invasion of NPC cells, accompanied by downregulation of MMP-2 and inactivation of FAK, Src, and ERK pathways. These findings indicate a usefulness of SAA on restraining NPC invasion and metastasis.

Preparation and Certification of a New Salvianolic Acid A Reference Material for Food and Drug Research

Salvianolic acid A (Sal A), a water-soluble ingredient in Danshen, has various biological activities. Sal A and its impurities have similar physical and chemical properties, as well as strong reducibility; therefore, they are difficult to prepare and purify. In this study, high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography. Furthermore, HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis, ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product. The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry, and their contents were quantified as well. Following the principles of ISO Guides 34:2009 and 35:2005, a Sal A reference material was certified, covering homogeneity studies, stability studies, characterization, and uncertainty estimations.

Chemical and pharmacological research on the polyphenol acids isolated from Danshen: A review of salvianolic acids

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.

Recombinant Dual-target MDM2/MDMX Inhibitor Reverses Doxorubicin Resistance through Activation of the TAB1/TAK1/p38 MAPK Pathway in Wild-type p53 Multidrug-resistant Breast Cancer Cells

Chemotherapy resistance represents a major obstacle for the treatment of patients with breast cancer (BC) and greatly restricts the therapeutic effect of the first-line chemotherapeutic agent doxorubicin (DOX). The present study aimed to investigate the feasibility of the recombinant dual-target murine double minute 2 (MDM2) and murine double minute X (MDMX) inhibitor in reversing the DOX resistance of BC. Both DOX-resistant human breast carcinoma cell lines exhibited a multidrug resistance (MDR) phenotype. The ability of the dual-target MDM2/MDMX inhibitor in reversing doxorubicin resistance was subsequently verified, (9.15 and 13.92 - fold reversal indexes) respectively. We observed that the MDM2/MDMX inhibitor in combination with DOX could suppress proliferation, promote cell cycle arrest and induce apoptosis. In addition, it was capable of reducing rhodamine123 efflux in DOX-resistance BC cell lines and further played a key role in BC nude mice model. The groups that were treated with the combination of the drugs had decreased P-glycoprotein/multidrug resistance-associated protein/cdc 2/Bcl-2 expression and increased CyclinB1/Bax expression. These effects were caused due to activation of the transforming growth factor β-activated kinase 1 (TAK1)-binding protein 1 (TAB1)/TAK1/p38 mitogen-activated protein kinase (MAPK) signaling pathway, as shown by small interfering RNA (siRNA) silencing and immumohistochemical staining of BC tissue sections. Furthermore, high MDM2/MDMX expression was positively associated with weak TAB1 expression in BC patients. Therefore, the recombinant dual-target MDM2/MDMX inhibitor could reverse doxorubicin resistance via the activation of the TAB1/TAK1/p38 MAPK pathway in wild-type p53 multidrug-resistant BC.

Bioreducible and acid-labile polydiethylenetriamines with sequential degradability for efficient transgelin-2 siRNA delivery

The transgelin-2 (TAGLN2) protein plays an important role in multidrug resistance in human breast cancer. siRNA mediated gene silencing of TAGLN2 is a promising strategy for paclitaxel resistance reversal in breast cancer. In this study, a series of bioreducible and acid-labile polydiethylenetriamines (PDs) with different proportions of cross-linkers were synthesized. TAGLN2 siRNA was condensed by PDs to form dual-responsive nanocomplexes, and these nanocomplexes were hypothesized to partially degrade in the acidic environment of endosomes, and then completely degrade in the reducing environment of the cytoplasm to release siRNA. It was found that PDs have good water solubility, acid-base buffering capacity, suitable degradability and high biocompatibility. Moreover, PDCKM can deliver TAGLN2 siRNA into MCF-7/PTX cells and inhibit the expression of TAGLN2 even better than PEI 25k. Besides, paclitaxel showed higher cytotoxicity in cells incubated with PDCKM/TAGLN2 siRNA nanocomplexes. These results suggested that PDs have great potential for safe and efficient siRNA delivery to reverse paclitaxel resistance in breast cancer.

Salvianolic acid A & B: potential cytotoxic polyphenols in battle against cancer via targeting multiple signaling pathways

Nature has generously offered life-saving therapies to mankind by providing evolutionarily optimized drug-like entities in the form of natural products. These splendid gifts of nature have served as most suitable candidates for anti-cancer drug discovery due to their pleiotropic activity on target molecules. This review aims to provide an update on the natural sources and bioactivities of such gifts from nature, salvianolic acid A & B, which are major bioactive constituents of a traditional Chinses medicinal herb, Salvia miltiorrhiza. Salvianolic acid A & B have been reported to owe anti-cancer, anti-inflammatory and cardioprotective activities. Currently salvianolic acids have been emerged as potent anti-cancer molecules. Salvianolic acid A & B fight cancer progression by prompting apoptosis, halting cell cycle and adjourning metastasis by targeting multiple deregulated signaling networks of cancer. Moreover, salvianolic acid A & B display potency towards sensitizing cancer cells to chemo-drugs. The review purposes that salvianolic acid A & B supply a novel opportunity for drug discovery but further experimentation is mandatory to embellish the knowledge of their pharmacological usage and to access their toxicological limits in order to establish these compounds as potential multitarget future drugs.

Transgelin-2: Biochemical and Clinical Implications in Cancer and Asthma

Transgelin-2 has been regarded as an actin-binding protein that induces actin gelation and regulates actin cytoskeleton. However, transgelin-2 has recently been shown to relax the myosin cytoskeleton of the airway smooth muscle cells by acting as a receptor for extracellular metallothionein-2. From a clinical perspective, these results support transgelin-2 as a promising therapeutic target for diseases such as cancer and asthma. The inhibition of transgelin-2 prevents actin gelation and thereby cancer cell proliferation, invasion, and metastasis. Conversely, the activation of transgelin-2 with specific agonists relaxes airway smooth muscles and reduces pulmonary resistance in asthma. Here, we review new studies on the biochemical properties of transgelin-2 and discuss their clinical implications for the treatment of immune, oncogenic, and respiratory disorders.

Transgelin-2 expression in breast cancer and its relationships with clinicopathological features and patient outcome

BACKGROUND

Transgelin-2 is an actin-binding protein that is widely expressed in various tissues and organs of the body, and reportedly may participate in the development and progression of multiple cancers. However, the clinical significance of transgelin-2 still remains controversial. We, therefore, aimed to determine the expression of transgelin-2 in breast cancer as well as its correlation with the tumorigenesis, progression and prognosis of human breast cancer.

METHODS

We collected tissues of 58 breast cancer patients from our hospital and 1090 samples from The Cancer Genome Atlas (TCGA) database. X-tile software was used to divide the transgelin-2 mRNA expression level in the database, logistic regression model was used to identify independent factors influencing transgelin-2 mRNA expression, and then Cox regression and Kaplan-Meier analysis were used to find factors that influence survival of breast cancer.

RESULTS

Transgelin-2 was significantly overexpressed in breast cancer tissues from our hospital and receiver operating characteristic (ROC) curve indicated that transgelin-2 may have diagnostic value. Meanwhile, estrogen receptor (ER) was in inverse correlation with transgelin-2 protein and mRNA expression, and transgelin-2 expression was positively correlated with Ki67 in breast cancer tissues. Logistic regression model revealed that TNM stage, ER and progesterone receptor (PR) status were independent factors for transgelin-2 mRNA expression. Patients with high transgelin-2 mRNA expression showed a poor survival and the trend was statistically significant only in ER-negative patients.

CONCLUSIONS

Transgelin-2 was expressed significantly higher in breast cancer cells and correlated with some clinicopathological factors. High transgelin-2 expression might predict poor prognosis for ER-negative patients.

Salvianolic Acids: Potential Source of Natural Drugs for the Treatment of Fibrosis Disease and Cancer

Salvianolic acids, the most effective and abundant compounds extracted from Salvia miltiorrhiza (Danshen), are well known for its good anti-oxidative activity. Danshen has been extensively used as a traditional medicine to treat cardiovascular-related diseases in China and other Asian countries for hundreds of years. Recently, more and more studies have demonstrated that salvianolic acids also have a good effect on the alleviation of fibrosis disease and the treatment of cancer. In vivo and in vitro experiments have demonstrated that salvianolic acids can modulate signal transduction within fibroblasts and cancer cells. It is discovered that the cancer treatment of salvianolic acids is not only because salvianolic acids promote the apoptosis of cancer cells, but also due to the inhibition of cancer-associated epithelial-mesenchymal transition processes. In this article, we review a variety of studies focusing on the comprehensive roles of salvianolic acids in the treatment of fibrosis disease and cancer. These perspectives on the therapeutic potential of salvianolic acids highlight the importance of these compounds, which could be the novel and attractive drugs for fibrosis disease and cancer.

PET Imaging on Dynamic Metabolic Changes after Combination Therapy of Paclitaxel and the Traditional Chinese Medicine in Breast Cancer-Bearing Mice

PURPOSE

The aim of the study was to non-invasively evaluate the anticancer activity of a traditional Chinese medicine-Huaier, combined with paclitaxel (PTX) in breast cancer bearing mice by detecting dynamic metabolic changes with positron emission tomography (PET).

PROCEDURES

Balb/c nude mice were randomly divided into one of the four groups: Huaier, PTX, PTX + Huaier, or the control. PET imaging with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) was performed to monitor the metabolic changes in BT474 (luminal B) and MDA-MB-231 (triple-negative) breast cancer xenografts. Immunohistochemistry (IHC) study was performed immediately after the final PET scan to assess the expressions of phosphatidylinositol 3-kinase (PI3K), phospho-AKT (p-AKT), caspase-3, and vascular endothelial growth factor (VEGF).

RESULTS

Compared to the control group, [¹⁸F]FDG accumulation demonstrated a significant decrease in PTX + Huaier (p < 0.01) or Huaier group (p < 0.05), which was consistent to the decreased expression of PI3K (p < 0.05) and p-AKT (p < 0.05) in the breast cancer xenografts.

CONCLUSION

The therapeutic effect of Huaier combined with PTX was superior than the PTX alone in BT474 and MDA-MB-231 breast cancer-bearing mice. [¹⁸F]FDG PET imaging could be a potential non-invasive approach to assess the metabolic changes after chemotherapy combined with traditional Chinese medicine in the breast cancer.

Oncogenic transgelin-2 is differentially regulated in isocitrate dehydrogenase wild-type vs. mutant gliomas

The presence of an isocitrate dehydrogenase (IDH1/2) mutation in gliomas is associated with favorable outcomes compared to gliomas without the mutation (IDH1/2 wild-type, WT). The underlying biological mechanisms accounting for improved clinical outcomes in IDH1/2 mutant gliomas remain poorly understood, but may, in part, be due to the glioma CpG island methylator phenotype (G-CIMP) and epigenetic silencing of genes. We performed profiling of IDH1/2 WT versus IDH1/2 mutant Grade II and III gliomas and identified transgelin-2 (TAGLN2), an oncogene and actin-polymerizing protein, to be expressed at significantly higher levels in IDH1/2 WT gliomas compared to IDH1/2 mutant gliomas. This differential expression of TAGLN2 was primarily due to promoter hypermethylation in IDH1/2 mutant gliomas, suggesting involvement of TAGLN2 in the G-CIMP. Our results also suggest that TAGLN2 may be involved in progression due to higher expression in glioblastomas compared to IDH1/2 WT gliomas of lower grades. Furthermore, our results suggest that TAGLN2 functions as an oncogene by contributing to proliferation and invasion when overexpressed in IDH1/2 WT glioma cells. Taken together, this study demonstrates a possible link between increased TAGLN2 expression, invasion and poor patient outcomes in IDH1/2 WT gliomas and identifies TAGLN2 as a potential novel therapeutic target for IDH1/2 WT gliomas.

Transgelin-2 is a novel target of KRAS-ERK signaling involved in the development of pancreatic cancer

Background

The KRAS mutation is the driving force of pancreatic ductal adenocarcinoma (PDAC). Downstream effectors of KRAS signal pathways are crucial to the development of PDAC. The purpose of this study was to investigate the relationship between KRAS mutation and transgelin-2. Transgelin-2 is highly expressed in PDAC tissues compared with adjacent normal tissues. The underlying mechanism for upregulating transgelin-2 is largely unknown.

Methods

Expression of transgelin-2 was analyzed by microarray data and qRT-PCR. The effect of KRAS signaling on transgelin-2 expression was examined in PDAC cells in the presence or absence of the ERK inhibitor. The interaction of transgelin-2 with ERK was confirmed by immunoprecipitation. ERK-mediated Phosphorylation of transglein-2 was detected by in vivo and in vitro kinase assays. The gain-of-function and loss-of-function approaches were used to examine the role of phosphorylation of transgelin-2 on cell proliferation. Phosphorylation of transgelin-2 was detected by immunohistochemistry in PDAC tissues.

Results

Here we found transgelin-2 expression was induced by KRAS mutation. In the case of KRAS mutation, ERK2 interacted with 29–31 amino acids of transgelin-2 and subsequently phosphorylated the S145 residue of transgelin-2. S145 phosphorylation of transgelin-2 played important roles in cell proliferation and tumorigenesis of PDAC. In addition, S145 phosphorylation of transgelin-2 was associated with a poor prognosis in patients with PDAC.

Conclusions

This study indicated that KRAS-ERK-mediated transeglin-2 phosphorylation played an important role in the development of PDAC. Inhibition of transgelin-2 phosphorylation may be a potential therapeutic strategy for targeting PDAC with KRAS mutation.

Reversal of doxorubicin-resistance by Salvia miltiorrhiza ligustrazine in the SHG44/doxorubicin glioma drug-resistant cell line

The multidrug resistance of glioma impedes chemo-radiotherapy and leads to adverse outcomes. In the present study, the doxorubicin (DOX)-resistant glioma SHG44/DOX cell line was established to investigate the effects and mechanisms of Salvia miltiorrhiza ligustrazine (SML), a traditional Chinese medicine, on the reversal of DOX-resistance. The SHG44/DOX cells grew continually in 0.1 µg/ml DOX and expressed increased levels of mRNA of multidrug resistance genes [multidrug resistance 1 (MDR1), multidrug resistance-associated protein 1 (MRP1) and lung resistance protein (LRP)] compared with the parental SHG44 cells. Treatment with DOX plus SML suppressed proliferation and promoted early apoptotic rates in SHG44/DOX cells, although treatment with DOX alone failed to inhibit SHG44/DOX cells. In addition, the levels of MDR1, MRP1 and LRP were downregulated by this traditional Chinese medicine, coupled with increased intracellular DOX concentrations. Tumor-bearing nude mouse models were also established using SHG44/DOX cells, and it was demonstrated that the tumor volumes and proliferation indexes were lower in the DOX plus SML group compared with the DOX alone group. The present data demonstrated that treatment with SML was able to reverse the DOX resistance of SHG44/DOX cells, which suggests that SML may be a potential adjuvant agent for glioma chemo-radiotherapy.

Phytotherapy and Nutritional Supplements on Breast Cancer

Breast cancer is the most frequent type of nonskin malignancy among women worldwide. In general, conventional cancer treatment options (i.e., surgery, radiotherapy, chemotherapy, biological therapy, and hormone therapy) are not completely effective. Recurrence and other pathologic situations are still an issue in breast cancer patients due to side effects, toxicity of drugs in normal cells, and aggressive behaviour of the tumours. From this point of view, breast cancer therapy and adjuvant methods represent a promising and challenging field for researchers. In the last few years, the use of some types of complementary medicines by women with a history of breast cancer has significantly increased such as phytotherapeutic products and nutritional supplements. Despite this, the use of such approaches in oncologic processes may be problematic and patient's health risks can arise such as interference with the efficacy of standard cancer treatment. The present review gives an overview of the most usual phytotherapeutic products and nutritional supplements with application in breast cancer patients as adjuvant approach. Regardless of the contradictory results of scientific evidence, we demonstrated the need to perform additional investigation, mainly well-designed clinical trials in order to establish correlations and allow for further validated outcomes concerning the efficacy, safety, and clinical evidence-based recommendation of these products.

Transgelin-2: A potential oncogenic factor

Actin-binding proteins are proteins that could bind to actin or actin fibers. As a member of actin-binding proteins, Transgelin-2 is expressed in smooth muscle cells and non-smooth muscle cells, and its gene, TAGLN2, is differently expressed in all cells and tissues. The deregulation of Transgelin-2 is considered to be correlated with progression of many kinds of diseases, especially the development of malignant tumors, such as invasion, metastasis, and resistance, yet the function and mechanism of action of Transgelin-2 remain elusive. Therefore, we reviewed the basic characteristics and function of Transgelin-2 and its biological role in various types of diseases in order to provide the theoretical basis for further research and new perspectives on cancer development.

Systematic Understanding of the Mechanism of Salvianolic Acid A via Computational Target Fishing

Salvianolic acid A (SAA) is one of the most abundant water-soluble and potent anti-oxidative compounds isolated from Danshen, a traditional Chinese medicine. A systematic overview of its mechanism of action is yet to be performed. In the present study, the druggability of SAA was measured using the TCMSP server, and potential targets of SAA were identified by PharmMapper and DRAR-CPI. Intersecting targets were then assessed by GeneMANIA and GO pathway analysis, and drug-target-pathway networks were constructed to give a visual view. The results showed that SAA has good druggability, and 13 putative protein targets were identified. Network analysis showed that these targets were associated with cancer, metabolism and other physiological processes. In summary, SAA is predicted to target multiple proteins and pathways to form a network that exerts systematic pharmacological effects.

Salvia miltiorrhiza Roots against Cardiovascular Disease: Consideration of Herb-Drug Interactions

Salvia miltiorrhiza root (Danshen) is widely used in Asia for its cardiovascular benefits and contains both hydrophilic phenolic acids and lipophilic tanshinones, which are believed to be responsible for its therapeutic efficacy. This review summarized the effects of these bioactive components from S. miltiorrhiza roots on pharmacokinetics of comedicated drugs with mechanic insights regarding alterations of protein binding, enzyme activity, and transporter activity based on the published data stemming from both in vitro and in vivo human studies. In vitro studies indicated that cytochrome P450 (CYP450), carboxylesterase enzyme, catechol-O-methyltransferase, organic anion transporter 1 (OAT1) and OAT3, and P-glycoprotein were the major targets involved in S. miltiorrhiza-drug interactions. Lipophilic tanshinones had much more potent inhibitory effects towards CYPs activities compared to hydrophilic phenolic acids, evidenced by much lower K_i values of the former. Clinical S. miltiorrhiza-drug interaction studies were mainly conducted using CYP1A2 and CYP3A4 probe substrates. In addition, the effects of coexisting components on the pharmacokinetic behaviors of those noted bioactive compounds were also included herein.

Systematic evaluation of multifunctional paclitaxel-loaded polymeric mixed micelles as a potential anticancer remedy to overcome multidrug resistance

Multidrug resistance (MDR) of tumor cells is becoming the main reason for the failure of chemotherapy and P-glycoprotein (P-gp) mediated drug efflux has demonstrated to be the key factor for MDR. To address this issue, a novel pH-responsive mixed micelles drug delivery system composed of dextran-g-poly(lactide-co-glycolide)-g-histidine (HDP) and folate acid-D-α-tocopheryl polyethylene glycol 2000 (FA-TPGS2K) copolymers has been designed for the delivery of antitumor agent, paclitaxel (PTX) via FA-receptor mediated cell endocytosis, into PTX-resistant breast cancer MCF-7 cells (MCF-7/PTX). PTX-loaded FA-TPGS2K/HDP mixed micelles were characterized to have a small size distribution, high loading content and excellent pH-responsive drug release profiles. Compared with HDP micelles, FA-TPGS2K/HDP mixed micelles showed a higher cytotoxicity against MCF-7 and MCF-7/PTX cells due to the synergistic effect of FA-receptor mediated cell endocytosis, pH-responsive drug release and TPGS mediated P-gp inhibition. P-gp expression level, ATP content and mitochondrial membrane potential change have been measured, the results indicated blank FA-TPGS2K/HDP mixed micelles could inhibit the P-gp activity by reducing the mitochondrial membrane potential and depleting ATP content but not down-regulating the P-gp expression. In vivo antitumor activities demonstrated FA-TPGS2K/HDP mixed micelles could reach higher antitumor activity compared with HDP micelles for MCF-7/PTX tumor cells. Histological assay also indicated that FA-TPGS2K/HDP mixed micelles showed strongly apoptosis inducing effect, anti-proliferation effect and anti-angiogenesis effect. All these evidences demonstrated this pH-sensitive FA-TPGS2K/HDP micelle-based drug delivery system is a promising approach for overcoming MDR.

STATEMENT OF SIGNIFICANCE

In this work, a novel FA-TPGS2K copolymer has been synthesized and used it to construct mixed micelles with HDP copolymer to overcome MDR effect. Furthermore, a series in vitro and in vivo evaluations have been made, which supported enough evidences for the efficient delivery of antitumor drug to MDR cells.

SB-T-121205, a next-generation taxane, enhances apoptosis and inhibits migration/invasion in MCF-7/PTX cells

Breast cancer is the leading cause of cancer death among women. Paclitaxel, a mitotic inhibitor, is highly effective in the treatment of breast cancer. However, development of resistance to paclitaxel limits its clinical use. Identifying new compounds and new strategies that are effective against breast cancer, in particular drug-resistant cancer, is of great importance. The aim of the present study was to explore the potential of a next-generation taxoid, SB-T-121205, in modulating the proliferation, migration and invasion of paclitaxel-resistant human breast cancer cells (MCF-7/PTX) and further evaluate the underlying molecular mechanisms. The results of MTT assay showed that SB-T-121205 has much higher potency to human breast cancer cells (MCF-7/S, MCF-7/PTX and MDA-MB-453 cells) than paclitaxel, while that the non-tumorigenic human bronchial epithelial cells (BEAS-2B) were slightly less sensitive to SB-T-121205 than paclitaxel. Flow cytometry and western blot methods revealed that SB-T-121205 induced cell cycle arrest at the G2/M phase and apoptosis in MCF-7/PTX cells through accelerating mitochondrial apoptotic pathway, resulting in reduction of Bcl-2/Bax ratio, as well as elevation of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP) levels. Moreover, SB-T-121205 changed epithelial-mesenchymal transition (EMT) property, and suppressed migration and invasion abilities of MCF-7/PTX cells. Additionally, SB-T-121205 exerted antitumor activity by inhibiting the transgelin 2 and PI3K/Akt pathway. These findings indicate that SB-T-121205 is a potent antitumor agent that promotes apoptosis and also recedes migration/invasion abilities of MCF-7/PTX cells by restraining the activity of transgelin 2 and PI3K/Akt, as well as mitochondrial apoptotic pathway. Such results suggest a potential clinical value of SB-T-121205 in breast cancer treatment.

Salvianolic Acid A, as a Novel ETA Receptor Antagonist, Shows Inhibitory Effects on Tumor in Vitro

Endothelin-1 (ET-1) autocrine and paracrine signaling modulate cell proliferation of tumor cells by activating its receptors, endothelin A receptor (ET_AR) and endothelin B receptor (ET_BR). Dysregulation of ET_AR activation promotes tumor development and progression. The potential of ET_AR antagonists and the dual-ET_AR and ET_BR antagonists as therapeutic approaches are under preclinical and clinical studies. Salvianolic acid A (Sal A) is a hydrophilic polyphenolic derivative isolated from Salvia miltiorrhiza Bunge (Danshen), which has been reported as an anti-cancer and cardio-protective herbal medicine. In this study, we demonstrate that Sal A inhibits ET_AR activation induced by ET-1 in both recombinant and endogenous ET_AR expression cell lines. The IC₅₀ values were determined as 5.7 µM in the HEK293/ET_AR cell line and 3.14 µM in HeLa cells, respectively. Furthermore, our results showed that Sal A suppressed cell proliferation and extended the doubling times of multiple cancer cells, including HeLa, DU145, H1975, and A549 cell lines. In addition, Sal A inhibited proliferation of DU145 cell lines stimulated by exogenous ET-1 treatment. Moreover, the cytotoxicity and cardio-toxicity of Sal A were assessed in human umbilical vein endothelial cells (HUVEC) and Human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs), which proved that Sal A demonstrates no cytotoxicity or cardiotoxicity. Collectively, our findings indicate that Sal A is a novel anti-cancer candidate through targeting ET_AR.

Next generation deep sequencing identified a novel lncRNA n375709 associated with paclitaxel resistance in nasopharyngeal carcinoma

Paclitaxel chemoresistance restricts the therapeutic efficacy and prognosis of patients with nasopharyngeal carcinoma (NPC). Accumulating evidence suggests that aberrant expression of long non-coding RNAs (lncRNAs) contributes to cancer progression. Therefore, we aimed to identify lncRNAs associated with paclitaxel resistance in NPC. First, paclitaxel-resistant CNE-2 cells (CNE-2-Pr) were successfully established and confirmed to be 33.26±8.70 times more resistant than parental CNE-2 cells. Then, differential expression profile of lncRNAs associated with NPC paclitaxel resistance, which contained a total of 2,670 known lncRNAs and 4,820 novel lncRNAs, was constructed via next generation sequencing technology. Our qRT-PCR confirmed that 7 of the top 8 lncRNAs were expressed with the same trend as the prediction, including 4 known lncRNAs (n375709, n377806, n369241 and n335785) and 3 novel lncRNAs (Unigene6646, Unigene6644 and Unigene1654). Our group initially focused on lncRNA n375709, which was the most significantly overexpressed lncRNA of the known lncRNAs. CCK-8 assays demonstrated that further inhibition of lncRNA n375709 increased the paclitaxel sensitivity in NPC 5-8F and 6-10B cells. In conclusion, the present study provided an overview of the expression profiles of lncRNAs correlated with paclitaxel resistance. lncRNA n375709 was identified to be involved in the regulation of NPC paclitaxel resistance.

Salvianolic acid A reverses the paclitaxel resistance and inhibits the migration and invasion abilities of human breast cancer cells by inactivating transgelin 2

Multidrug resistance and tumor migration and invasion are the major obstacles to effective breast cancer chemotherapy, but the underlying molecular mechanisms remain unclear. This study investigated the potential of transgelin 2 and salvianolic acid A to modulate the resistance and the migration and invasion abilities of paclitaxel-resistant human breast cancer cells (MCF-7/PTX). MCF-7/PTX cells were found to exhibit not only a high degree of resistance to paclitaxel, but also strong migration and invasion abilities. Small interfering RNA-mediated knockdown of TAGLN2 sensitized the MCF-7/PTX cells to paclitaxel, and inhibited their migration and invasion abilities. In addition, we also observed that combined salvianolic acid A and paclitaxel treatment could reverse paclitaxel resistance, markedly inhibit tumor migration and invasion, and suppress the expression of transgelin 2 in MCF-7/PTX cells. These findings indicate that salvianolic acid A can reverse the paclitaxel resistance and inhibit the migration and invasion abilities of human breast cancer cells by down-regulating the expression of transgelin 2, and hence could be useful in breast cancer treatments.

HDACI regulates the PI3K/Akt signaling pathway to reverse MCF-7/PTX resistance by inhibiting SET

The occurrence of chemoresistance greatly restricts the efficacy of antitumor drugs, and so novel agents are urgently needed to abrogate resistant phenotypes.

Medicarpin and millepurpan, two flavonoids isolated from Medicago sativa, induce apoptosis and overcome multidrug resistance in leukemia P388 cells

BACKGROUND

High consumption of flavonoids has been associated with a decrease risk of cancer. Alfalfa (Medicago sativa) leaves have been widely used in traditional medicine and is currently used as a dietary supplement because of their high nutrient content. We previously reported the cytotoxic activity of alfalfa leaf extracts against several sensitive and multidrug resistant tumor cell lines.

HYPOTHESIS/PURPOSE

We aimed to determine whether medicarpin and millepurpan, two isoflavonoids isolated from alfalfa leaves, may have pro-apoptotic effects against drug-sensitive (P388) and multidrug resistant P388 leukemia cells (P388/DOX).

STUDY DESIGN/METHODS

Cells were incubated with medicarpin or millepurpan for the appropriate time. Cell viability was assessed by the MTT assay. DNA fragmentation was analyzed by agarose gel electrophoresis. Cell cycle analysis was realized by flow cytometry technics. Caspases 3 and 9 activities were measured using Promega caspACE assay kits. Proteins and genes expression were visualized respectively by western-blot using specific antibodies and RT-PCR assay.

RESULTS

P-glycoprotein-expressing P388/DOX cells did not show resistance to medicarpin (IC50 ≈ 90 µM for P388 and P388/DOX cells) and millepurpan (IC50 = 54 µM and 69 µM for P388 and P388/DOX cells, respectively). Treatment with medicarpin or millepurpan triggered apoptosis in sensitive as well as multidrug resistant P388 cells. These effects were mediated through the mitochondrial pathway by modifying the balance pro/anti-apoptotic proteins. While 3 µM doxorubicin alone could not induce cell death in P388/DOX cells, concomitant treatment with doxorubicin and subtoxic concentration of medicarpin or millepurpan restored the pro-apoptotic cascade. Each compound increased sensitivity of P388/DOX cells to doxorubicin whereas they had no effect in sensitive P388 cells. Vinblastine cytotoxicity was also enhanced in P388/DOX cells (IC50 = 210 nM to 23 and 25 nM with medicarpin and millepurpan, respectively). This improved sensitivity was mediated by an increased uptake of doxorubicin in P388/DOX cells expressing P-gp. P-gp expression was not altered by exposure to medicarpin and millepurpan.

CONCLUSION

These data indicate that medicarpin and millepurpan possess pro-apoptotic properties and potentiate the cytotoxicity of chemotherapy drugs in multidrug resistant P388 leukemia cells by modulating P-gp-mediated efflux of drugs. These flavonoids may be used as chemopreventive agents or as sensitizer to enhance cytotoxicity of chemotherapy drugs in multidrug resistant cancer cells.

Expression of Cofilin-1 and Transgelin in Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has attracted much research attention around the world, and the number of ESCC cases has increased gradually in recent years. Identifying the specific biomarkers of ESCC is an effective approach for the early diagnosis of tumors.

MATERIAL AND METHODS

Immunohistochemical streptavidin-peroxidase method was used to determine the expressions of Cofilin-1 and transgelin in 68 patients with esophageal squamous cell carcinoma (ESCC) and 48 individuals with normal esophageal tissues. In addition to the relationships between the expression of Cofilin-1 and transgelin, the clinicopathologic features of ESCC were also discussed. The correlation between Cofilin-1 and transgelin protein expression in ESCC was analyzed.

RESULTS

(1) The positive expression rates of Cofilin-1 and transgelin were 60.3% (41/68) and 54.4% (37/68) in esophageal carcinoma tissue, respectively. The positive expression rates of Cofilin-1 and transgelin in normal esophageal tissue were 27.1% (13/48) and 29.1% (14/48), respectively. The differences were statistically significant (P<0.05). (2) The positive expression rate of Cofilin-1 did not differ significantly (P>0.05) with sex, age, ethnicity, tumor size, or infiltration depth; but did have a statistically significant (P<0.05) difference with various degrees of tumor differentiation, lymph node metastasis, and clinical stages. (3) The positive expression rate of transgelin did not differ significantly (P>0.05) with sex, age, ethnicity, tumor size, infiltration depth, and clinical stage, but did significantly (P<0.05) differ with degree of tumor differentiation and lymph node metastasis.

CONCLUSIONS

Cofilin-1 and transgelin may play roles in the carcinogenesis and development of esophageal squamous cell carcinoma. Cofilin-1 may be useful as an important biomarker for indicating the degree of malignancy of esophageal squamous cell carcinoma, and the detection of transgelin is valuable in early diagnosis of esophageal squamous cell carcinoma.

Paclitaxel resistance in MCF-7/PTX cells is reversed by paeonol through suppression of the SET/phosphatidylinositol 3-kinase/Akt pathway

Breast cancer is one of the most prevalent types of malignant tumor. Paclitaxel is widely used in the treatment of breast cancer; however, the major problem contributing to the failure of chemotherapy in breast cancer is the development of drug resistance. Therefore, it is necessary to identify novel therapeutic targets and reversal agents for breast cancer. In the present study, the protein expression levels of SET, protein phosphatase 2A (PP2A) and phosphatidylinositol 3-kinase (PI3K)/Akt pathway were determined in MCF-7/PTX human breast carcinoma paclitaxel-resistant cells using western blot analysis. Small interference RNAs (siRNAs) were used to knock down the gene expression of SET in MCF-7/PTX cells and the cell viability was assessed following treatment with paclitaxel, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays and flow cytometry. In addition, western blot analysis was used to determined PI3K/Akt pathway activity following SET knockdown. Furthermore, the reversal effects of paeonol on paclitaxel, and its underlying mechanisms of action, were investigated using western blot analysis and reverse transcription-quantitative polymerase chain reaction. The results demonstrated that increased levels of SET and PI3K/Akt pathway proteins were present in the MCF-7/PTX cells, compared with normal MCF-7 cells. Knockdown of SET significantly sensitized MCF-7/PTX cells to paclitaxel and induced cell apoptosis. In addition, the expression levels of the adenosine triphosphate binding cassette (ABC) transporter proteins were significantly reduced in the MCF-7/PTX cells compared with the normal MCF-7 cells. SET-induced paclitaxel resistance was found to be associated with the activation of the PI3K/Akt pathway. Paeonol significantly reduced the mRNA and protein expression levels of SET in the MCF-7/PTX cells. Furthermore, paeonol significantly sensitized the MCF-7/PTX to paclitaxel via regulation of ABC transporters, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein. In addition, paeonol inhibited SET-mediated paclitaxel resistance by attenuating PI3K/Akt pathway activity in the MCF-7/PTX cells. In conclusion, the results of the present study demonstrated that SET was associated with paclitaxel resistance in MCF-7/PTX cells, and that paeonol reversed paclitaxel resistance in MCF-7/PTX cells by downregulating the activity of the SET/PP2A/Akt pathway.