Overexpression of survivin via activation of ERK1/2, Akt, and NF-κB plays a central role in vincristine resistance in multiple myeloma cells

Engineering redirected NF-κB/OIP5 expression programs to enhance tumor responses to chemotherapy in bladder cancer

Nuclear factor kappa-B (NF-κB), a pivotal transcriptional regulator, plays a crucial role in modulating downstream genes implicated in tumor drug resistance. We establish a programmable system within bladder cancer cells to tailor drug responses by employing a synthetic clustered regularly interspaced short palindromic repeats (CRISPR)-based expression strategy that emulates natural transcriptional regulators. Our investigation uncovers the functional significance of Opa-interacting protein 5 (OIP5), upregulated upon NF-κB activation, as a key regulator governing drug-resistance to vincristine (VCR) treatment in bladder cancer. Through engineered guide RNAs (sgRNAs) targeting OIP5 to integrate NF-κB aptamers, we construct a modular scaffold RNA that encodes both the target locus and regulatory functionality. This engineered CRISPR scaffold RNA effectively responds to VCR stimulus by binding with activated NF-κB. Intriguingly, it redirects NF-κB to attenuate OIP5 expression-a reversal of its original role-while concurrently obstructing multiple NF-κB-mediated drug resistance pathways. This dual action thwarts drug resistance development. Further enhancing therapeutic potential, we develop a versatile nanoparticle system capable of co-delivering CRISPR scaffold RNAs and VCR. This synergistic approach demonstrates potent anti-tumor effects in both in vitro and in vivo settings. Our nanoparticle-mediated combination presents a compelling proof-of-concept, showcasing the utility of engineered CRISPR-based synthetic expression programs to reconfigure cellular drug responses and heighten tumor cell susceptibility to chemotherapy.

Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment

How to effectively transform the pro-oncogenic tumor microenvironments (TME) surrounding a tumor into an anti-tumoral never fails to attract people to study. Small interfering RNA (siRNA) is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference (RNAi). The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years. Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions. However, the manufacture of a siRNA delivery system faces three major obstacles, i.e., appropriate cargo protection, accurately targeted delivery, and site-specific cargo release. In the following review, we summarized the pharmacological actions of siRNA drugs in remolding TME. In addition, the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed. In the meanwhile, the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented. Ultimately, we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy. This summary offers a thorough analysis and roadmap for general readers working in the field.

LINC00511 promotes cervical cancer progression by regulating the miR-497-5p/MAPK1 axis

BACKGROUND

Long non-coding RNA (lncRNA) exhibits a crucial role in multiple human malignancies. The expression of lncRNA LINC00511, reportedly, is aberrantly up-regulated in several types of tumors. Our research was aimed at deciphering the role and mechanism of LINC00511 in the progression of cervical cancer (CC).

METHOD

Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to quantify the expression levels of LINC00511, miR-497-5p and MAPK1 mRNA in CC tissues and cell lines. Cell counting kit-8 (CCK-8), 5-bromo-2'-deoxyuridine (BrdU) and Transwell assays were conducted for detecting the proliferation, migration and invasion of CC cells. Dual-luciferase reporter gene experiments were performed to verify the targeting relationships amongst LINC00511, miR-497-5p and MAPK1. Besides, MAPK1 expression in CC cells was detected via Western blot after LINC00511 and miR-497-5p were selectively regulated.

RESULTS

Up-regulation of LINC00511 expression in CC tissues and cell lines was observed, which was in association with tumor size, clinical stage and lymph node metastasis of the patients. LINC00511 overexpression facilitated the proliferation, migration and invasion of CC cells, while opposite effects were observed after knockdown of LINC00511. Mechanistically, LINC00511 was capable of targeting miR-497-5p and up-regulating MAPK1 expression.

CONCLUSION

LINC00511/miR-497-5p/MAPK1 axis regulates CC progression.

An engineered abcb4 expression model reveals the central role of NF-κB in the regulation of drug resistance in zebrafish

Multi-drug resistance (MDR) is a phenomenon that tumor cells are exposed to a chemotherapeutic drug for a long time and then develop resistance to a variety of other anticancer drugs with different structures and different mechanisms. The in vitro studies of tumor cell lines cannot systematically reflect the role of MDR gene in vivo, and the cost of in vivo studies of transgenic mice as animal models is high. Given the myriad merits of zebrafish relative to other animal models, we aimed to establish a screening system using zebrafish stably expressing ATP-binding cassette (ATP-cassette) superfamily transporters and unveil the potential regulatory mechanism. We first used the Tol2-mediated approach to construct a Tg (abcb4:EGFP) transgenic zebrafish line with ATP-binding cassette (ABC) subfamily B member 4 (abcb4) gene promoter to drive EGFP expression. The expression levels of abcb4 and EGFP were significantly increased when Tg(abcb4:EGFP) transgenic zebrafish embryos were exposed to doxorubicin (DOX) or vincristine (VCR), and the increases were accompanied by a marked decreased accumulation of rhodamine B (RhB) in embryos, indicating a remarkable increase in DOX or VCR efflux. Mechanistically, Akt and Erk signalings were activated upon the treatment with DOX or VCR. With the application of Akt and Erk inhibitors, drug resistance was reversed with differing responsive effects. Notably, downstream NF-κB played a central role in the regulation of abcb4-mediated drug resistance. Taken together, the data indicate that the engineered Tg(abcb4:EGFP) transgenic zebrafish model is a new platform for screening drug resistance in vivo, which may facilitate and accelerate the process of drug development.

The abnormal expression of chromosomal region maintenance 1 (CRM1)-survivin axis in ovarian cancer and its related mechanisms regulating proliferation and apoptosis of ovarian cancer cells

Ovarian cancer (OC) is the main type of cancer that affects the female reproductive system and has a high morbidity and mortality rate. This study aimed to explore the regulatory effect of the chromosomal region maintenance 1 (CRM1)-survivin axis on the progression of OC. Ovarian cancer cells were transfected with pcDNA3.1-survivin and short hairpin RNA (sh)-CRM1. Cell proliferation was analyzed by cell counting kit-8 (CCK8), 5-ethynyl-2´-deoxyuridine (EdU) staining, and colony formation assays. Apoptosis was detected using flow cytometry. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed to analyze the expression of RNA and protein, respectively. qRT-PCR and prognostic correlation analyses revealed that CRM1 is highly expressed in OC cells and related to survival. The results of qRT-PCR, CCK8, colony formation test, EdU staining, flow cytometry, and Western blotting showed that CRM1 silencing inhibited the proliferation and colony formation of OVCAR 3 and SKOV3 cells and promoted cell apoptosis by promoting Caspase-3 activation. Survivin was positively regulated by CRM1 and promoted the development of OC. The results of the rescue experiment showed that overexpression of survivin reversed the inhibitory effect of CRM1 knockdown on the proliferation of ovarian cancer cells and its inhibitory effect on apoptosis. Our findings confirm the role of the CRM1-survivin signal transduction axis in OC by regulating the proliferation and apoptosis of OC cells, and may thus serve as a potential therapeutic target for OC.

Crosstalk between endoplasmic reticulum stress and oxidative stress: a dynamic duo in multiple myeloma

Under physiological and pathological conditions, cells activate the unfolded protein response (UPR) to deal with the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum. Multiple myeloma (MM) is a hematological malignancy arising from immunoglobulin-secreting plasma cells. MM cells are subject to continual ER stress and highly dependent on the UPR signaling activation due to overproduction of paraproteins. Mounting evidence suggests the close linkage between ER stress and oxidative stress, demonstrated by overlapping signaling pathways and inter-organelle communication pivotal to cell fate decision. Imbalance of intracellular homeostasis can lead to deranged control of cellular functions and engage apoptosis due to mutual activation between ER stress and reactive oxygen species generation through a self-perpetuating cycle. Here, we present accumulating evidence showing the interactive roles of redox homeostasis and proteostasis in MM pathogenesis and drug resistance, which would be helpful in elucidating the still underdefined molecular pathways linking ER stress and oxidative stress in MM. Lastly, we highlight future research directions in the development of anti-myeloma therapy, focusing particularly on targeting redox signaling and ER stress responses.

Anlotinib suppresses metastasis and multidrug resistance via dual blockade of MET/ABCB1 in colorectal carcinoma cells

Anlotinib, a highly selective multi-targeted tyrosine kinase inhibitor (TKI) has therapeutic effects on non-small-cell lung cancer (NSCLC). In this study, the anti-tumor activity and molecular mechanism of anlotinib in metastatic colorectal cancer (mCRC) was explored. The anti-angiogenesis, anti-metastasis, anti-proliferative, and anti-multidrug resistance efficacy of anlotinib were analyzed by using in vitro and in vivo models of human CRC cells. The results indicated that anlotinib boosted chemo-sensitivity of CRC cells, and restrained its proliferation. Besides the suppression of the MET signaling pathway, anlotinib also inhibited invasion and migration of CRC cells. Furthermore, anlotinib prevented VEGF-induced angiogenesis, N-cadherin (CDH2)-induced cell migration, and reversed ATP-binding cassette subfamily B member 1 (ABCB1) -mediated CRC multidrug resistance in CRC. The CRC liver metastasis and subcutaneously implanted xenograft model testified that anlotinib could inhibit proliferation and liver metastasis in CRC cells. Such an observation suggested that a combination of anlotinib with anti-cancer drugs could attenuate angiogenesis, metastasis, proliferative, and multidrug resistance, which constitutes a novel treatment strategy for CRC patients with metastasis.

Activation of Serum/Glucocorticoid Regulated Kinase 1/Nuclear Factor-κB Pathway Are Correlated with Low Sensitivity to Bortezomib and Ixazomib in Resistant Multiple Myeloma Cells

Multiple myeloma (MM) is an incurable malignancy often associated with primary and acquired resistance to therapeutic agents, such as proteasome inhibitors. However, the mechanisms underlying the proteasome inhibitor resistance are poorly understood. Here, we elucidate the mechanism of primary resistance to bortezomib and ixazomib in the MM cell lines, KMS-20, KMS-26, and KMS-28BM. We find that low bortezomib and ixazomib concentrations induce cell death in KMS-26 and KMS-28BM cells. However, high bortezomib and ixazomib concentrations induce cell death only in KMS-20 cells. During Gene Expression Omnibus analysis, KMS-20 cells exhibit high levels of expression of various genes, including anti-phospho-fibroblast growth factor receptor 1 (FGFR1), chemokine receptor type (CCR2), and serum and glucocorticoid regulated kinase (SGK)1. The SGK1 inhibitor enhances the cytotoxic effects of bortezomib and ixazomib; however, FGFR1 and CCR2 inhibitors do not show such effect in KMS-20 cells. Moreover, SGK1 activation induces the phosphorylation of NF-κB p65, and an NF-κB inhibitor enhances the sensitivity of KMS-20 cells to bortezomib and ixazomib. Additionally, high levels of expression of SGK1 and NF-κB p65 is associated with a low sensitivity to bortezomib and a poor prognosis in MM patients. These results indicate that the activation of the SGK1/NF-κB pathway correlates with a low sensitivity to bortezomib and ixazomib, and a combination of bortezomib and ixazomib with an SGK1 or NF-κB inhibitor may be involved in the treatment of MM via activation of the SGK1/NF-κB pathway.

Mutant Kras as a Biomarker Plays a Favorable Role in FL118-Induced Apoptosis, Reactive Oxygen Species (ROS) Production and Modulation of Survivin, Mcl-1 and XIAP in Human Bladder Cancer

Simple Summary

FL118 is a novel orally available small molecule anticancer drug. We found that bladder cancer cells with a mutant Kras is highly sensitive to FL118-induced cell growth inhibition and cell death induction through inhibiting the anti-cancer cell death and drug resistance factors (survivin, Mcl-1, XIAP). In the Kras-mutation bladder cancer cells, FL118 can stimulate the reactive oxygen species (ROS) over-production for killing bladder cancer cells and inhibiting bladder cancer cell-established tumor growth. Elimination of mutant Kras by Kras-specific shRNA technology in mutant Kras-containing bladder cancer cell-established tumor decreased FL118 effectiveness to inhibit bladder cancer tumor growth. In this regard, mutant Kras is a potential favorable biomarker for FL118. This finding is significant because mutant Kras is known to be a formidable challenge treatment resistant factor in various types of cancer. Thus, FL118 could use mutant Kras as favorable biomarker for patient selection to carry out precision medicine.

Abstract

Tumor heterogeneity in key gene mutations in bladder cancer (BC) is a major hurdle for the development of effective treatments. Using molecular, cellular, proteomics and animal models, we demonstrated that FL118, an innovative small molecule, is highly effective at killing T24 and UMUC3 high-grade BC cells, which have Hras and Kras mutations, respectively. In contrast, HT1376 BC cells with wild-type Ras are insensitive to FL118. This concept was further demonstrated in additional BC and colorectal cancer cells with mutant Kras versus those with wild-type Kras. FL118 strongly induced PARP cleavage (apoptosis hallmark) and inhibited survivin, XIAP and/or Mcl-1 in both T24 and UMUC3 cells, but not in the HT1376 cells. Silencing mutant Kras reduced both FL118-induced PARP cleavage and downregulation of survivin, XIAP and Mcl-1 in UMUC3 cells, suggesting mutant Kras is required for FL118 to exhibit higher anticancer efficacy. FL118 increased reactive oxygen species (ROS) production in T24 and UMUC3 cells, but not in HT1376 cells. Silencing mutant Kras in UMUC3 cells reduced FL118-mediated ROS generation. Proteomics analysis revealed that a profound and opposing Kras-relevant signaling protein is changed in UMUC3 cells and not in HT1376 cells. Consistently, in vivo studies indicated that UMUC3 tumors are highly sensitive to FL118 treatment, while HT1376 tumors are highly resistant to this agent. Silencing mutant Kras in UMUC3 cell-derived tumors decreases UMUC3 tumor sensitivity to FL118 treatment. Together, our studies revealed that mutant Kras is a favorable biomarker for FL118 targeted treatment.

Dasatinib reverses drug resistance by downregulating MDR1 and Survivin in Burkitt lymphoma cells

Background

Current chemotherapies for Burkitt lymphoma (BL) have dramatically improved its clinical outcome. However, chemoresistance can lead to chemotherapy failure and very poor prognosis; thus, novel strategies are urgently required for patients with drug-resistant BL. To investigate the mechanisms underlying drug resistance in BL, we established drug-resistant BL cell lines: HS-Sultan/ADM (adriamycin-resistant), HS-Sultan/VCR (vincristine-resistant), HS-Sultan/DEX (dexamethasone-resistant), and HS-Sultan/L-PAM (melphalan-resistant).

Methods

Drug transporter and survival factor expression were investigated the using western blotting and real time polymerase chain reaction. Cell survival was analyzed by trypan blue dye exclusion method.

Results

The established cell lines acquired cross-resistance to adriamycin, vincristine, dexamethasone, and melphalan and exhibited 50% inhibitory concentration values 106-, 40-, 81-, and 45-fold higher than the parental cell lines, respectively. We found that protein and mRNA expression of MDR1 and Survivin were higher in drug-resistant BL cells than in the parent cells. Treatment with verapamil, an MDR1 inhibitor, or Survivin siRNA alongside each anti-cancer drug suppressed the proliferation of all drug-resistant BL cells. Src kinase activity was higher in all resistant cell lines than the parental cells; suppressing Src with dasatinib restored drug sensitivity by reducing MDR1 and Survivin expression.

Conclusions

MDR1 and Survivin upregulation are responsible for resistance to conventional drugs and dasatinib can restore drug sensitivity by reducing MDR1 and Survivin expression in drug-resistant BL cells. Src inhibitors could therefore be a novel treatment strategy for patients with drug resistant BL.

The role of deubiquitinating enzymes in cancer drug resistance

Drug resistance is a well-known phenomenon leading to a reduction in the effectiveness of pharmaceutical treatments. Resistance to chemotherapeutic agents can involve various intrinsic cellular processes including drug efflux, increased resistance to apoptosis, increased DNA damage repair capabilities in response to platinum salts or other DNA-damaging drugs, drug inactivation, drug target alteration, epithelial-mesenchymal transition (EMT), inherent cell heterogeneity, epigenetic effects, or any combination of these mechanisms. Deubiquitinating enzymes (DUBs) reverse ubiquitination of target proteins, maintaining a balance between ubiquitination and deubiquitination of proteins to maintain cell homeostasis. Increasing evidence supports an association of altered DUB activity with development of several cancers. Thus, DUBs are promising candidates for targeted drug development. In this review, we outline the involvement of DUBs, particularly ubiquitin-specific proteases, and their roles in drug resistance in different types of cancer. We also review potential small molecule DUB inhibitors that can be used as drugs for cancer treatment.

Overactivation of Akt Contributes to MEK Inhibitor Primary and Acquired Resistance in Colorectal Cancer Cells

RAS and BRAF-mutated colorectal cancers are associated with resistance to chemotherapy and poor prognosis, highlighting the need for new therapeutic strategies. Although these cancers sometimes respond to mitogen activated protein kinase kinase (MEK) inhibitor treatment, they often acquire resistance via mechanisms, which are poorly understood. Here, we investigated the mechanism of MEK inhibitor resistance in primary- and acquired-resistant cells. Cell viability was examined using the trypan blue dye exclusion assay. Protein expression was analyzed by western blotting. Somatic mutations in colorectal cancer cells were investigated using the polymerase chain reaction array. PD0325901 and trametinib induced cell death in LoVo and Colo-205 cells but not in DLD-1 and HT-29 cells, which have a PIK3CA mutation constitutively activating Akt and NF-κB. Treatment with PD0325901 and trametinib suppressed ERK1/2 activation in all four cell lines but only induced Akt and NF-κB activation in DLD-1 and HT-29 cells. Inhibition of Akt but not NF-κB, overcame MEK inhibitor resistance in DLD-1 and HT-29 cells. Acquired-resistant LoVo/PR, Colo-205/PR and LoVo/TR cells have constitutively active Akt due to a M1043V mutation in the kinase activation loop of PIK3CA and Akt inhibitor resensitized these cells to MEK inhibitor. These results demonstrate that the overactivation of Akt plays a critical role in MEK inhibitor primary and acquired resistance and implicate combined Akt/MEK inhibition as a potentially useful treatment for RAS/BRAF-mutated colorectal cancer.

MicroRNA-675 directly targets MAPK1 to suppress the oncogenicity of papillary thyroid cancer and is sponged by long non-coding RNA RMRP

Background

MicroRNA-675-5p (miR-675-5p) is dysregulated in multiple human cancers, but its involvement in papillary thyroid cancer (PTC) remains to be investigated. This study aimed to examine the expression pattern of miR-675 in PTC, determine the effects of miR-675 on regulating the progression of PTC, and to explore the underlying molecular mechanisms.

Methods

The expression profile of miR-675 in PTC tissues and cell lines was determined using RT-qPCR. CCK-8, transwell migration and invasion assays, and xenograft tumors in nude mice were employed to analyze proliferation, in vitro migration and invasion, and in vivo tumor growth of PTC cells, respectively. The putative target of miR-675 was predicted using bioinformatic algorithms and was confirmed using luciferase reporter assays, RT-qPCR, and Western blotting.

Results

miR-675 expression was decreased in PTC tissues and cell lines. A low level of miR-675 expression was significantly correlated with lymphatic metastasis and TNM stage in PTC patients. Ectopic miR-675 expression suppressed PTC cell proliferation, migration, and invasion in vitro and hindered tumor growth in vivo. Mitogen-activated protein kinase 1 (MAPK1) was found to be the direct target gene of miR-675 in PTC cells. MAPK1 reintroduction negated the tumor-suppressing effect of miR-675 overexpression in PTC cells. Furthermore, the lncRNA mitochondrial RNA processing endoribonuclease (RMRP) functioned as a ceRNA of miR-675 in PTC cells. Silencing RMRP expression inhibited the growth and metastasis of PTC cells by sponging miR-675 and regulating MAPK1.

Conclusion

These findings revealed that miR-675 directly targets MAPK1 and is sponged by lncRNA RMRP to inhibit the oncogenicity of PTC, suggesting the RMRP-miR-675-MAPK1 pathway is an effective target for the treatment of PTC patients.

Response prediction to oxaliplatin plus 5-fluorouracil chemotherapy in patients with colorectal cancer using a four-protein immunohistochemical model

The response of cancer patients to oxaliplatin combined with 5-fluorouracil (5-FU) is difficult to predict. It has been reported that carcinoma-associated fibroblasts (CAFs) could induce AKT and ERK phosphorylation, and upregulate survivin expression in colorectal cancer (CRC) cells, which could lead to oxaliplatin plus 5-FU resistance. A total of 71 patients with advanced CRC (aCRC) treated with oxaliplatin plus 5-FU were included in the present study. These patients comprised 46 chemotherapy responders and 25 non-responders. The expression levels of α-smooth muscle actin (α-SMA), phosphorylated (p)-AKT, p-ERK and survivin were determined by immunohistochemical evaluation of paraffin-embedded samples from patients. A predictive model was established using a Probabilistic Neural Network model. The high expression of α-SMA, p-AKT and survivin in patients with aCRC were associated with oxaliplatin plus 5-FU resistance (P<0.001, P=0.023 and P=0.001, respectively). Furthermore, patients with stage IV CRC exhibiting high expression levels of α-SMA and survivin experienced a reduced progression-free survival time compared with patients with low expressions of α-SMA and survivin (5.5 vs. 15.0 months; 5.5 vs. 15.0 months; P=0.005 and P=0.001, respectively). Stage IV CRC and high survivin expression predicted a reduced overall survival time compared with that for patients with stage IV CRC and low survivin expression (50.0 vs. 15.0 months; P<0.001). Patients with α-SMA, p-AKT, p-ERK and survivin overexpression were more likely to present with intrinsic resistance to the oxaliplatin plus 5-FU regimen (the accuracies of modeling, validation and prediction were 83.7, 92.9 and 85.7%, respectively). In conclusion, the multifactorial predictive biomarker model of α-SMA, p-AKT, p-ERK and survivin expression for patients with aCRC to predict intrinsic resistance to oxaliplatin plus 5-FU regimens is of great efficiency and accuracy. Patients with high expression of this predictive model may be intrinsically resistant to the oxaliplatin and 5-FU regimen.

Nonsteroidal Anti-Inflammatory Drugs Prevent Vincristine-Dependent Cancer-Associated Fibroblasts Formation

Vincristine is used in the clinical treatment of colon cancer, especially in patients diagnosed in the advanced phase of cancer development. Unfortunately, similar to other agents used during antitumor therapy, vincristine might induce chemoresistance. Studies of this process focus mainly on the analysis of the molecular mechanisms within cancer, usually ignoring the role of stromal cells. Our present findings confirm that vincristine stimulates the secretion of tumor growth factors class beta and interleukin-6 from cancer-associated fibroblasts as a result of paracrine stimulation by cancer cells. Based on alterations in morphology, modulation of capillary formation, and changes in endothelial and mesenchymal marker profile, our findings demonstrate that higher levels of tumor growth factor-βs and interleukin-6 enhance cancer-associated fibroblast-like cell formation through endothelial–mesenchymal transition and that nonsteroidal anti-inflammatory drug treatment (aspirin and ibuprofen) is able to inhibit this phenomenon. The process appears to be regulated by the rate of microtubule polymerization, depending on β-tubulin composition. While higher levels of tubulin-β2 and tubulin-β4 caused slowed polymerization and reduced the level of factors secreted to the extracellular matrix, tubulin-β3 induced the opposite effect. We conclude that nonsteroidal anti-inflammatory drugs should be considered for use during vincristine monotherapy in the treatment of patients diagnosed with colorectal cancer.

Chinese Herbal Medicine Wenxia Changfu Formula Reverses Cell Adhesion-Mediated Drug Resistance via the Integrin β1-PI3K-AKT Pathway in Lung Cancer

In the treatment of lung cancer, the multidrug resistance to chemotherapeutic drugs is one of the reasons of low rates for cure and treatment failure, the combination of chemotherapeutic drugs and traditional Chinese medicine can increase the sensitivity of chemotherapy and reduce its adverse effects. Our previous study has proved that Chinese herbal medicine (CHM) Wenxia Changfu Formula (WCF for short) effectively enhances chemotherapeutic efficacy in lung cancer treatment and reverses multidrug resistance in lung cancer cells in vitro. The present study aims to investigate the effect and mechanism of WCF in reversing cell adhesion-mediated drug resistance of lung cancer by using A549 three-dimensional cell culture and nude mouse model of the A549 cell line with Integrin β1 overexpression. We show that the combination of WCF with DDP can decrease proliferation of lung cancer cells by inducing cell cycle arrest and apoptosis. Moreover, we find that the combination of WCF with DDP suppresses the expression of certain molecules which regulate cell cycle and apoptosis. Mechanistically, we show that the Integrin β1, FAK, PI3K, and AKT protein expressions are suppressed by DDP and even more responses are observed when DDP and WCF are combined, showing WCF treatment enhances the effect of commonly used anticancer drugs. In line with the above findings, our results confirm that WCF reverses cell adhesion-mediated drug resistance of lung cancer via inactivating Integrin β1/PI3K/AKT and apoptosis induction.

Up-regulation of microRNA-497 inhibits the proliferation, migration and invasion but increases the apoptosis of multiple myeloma cells through the MAPK/ERK signaling pathway by targeting Raf-1

Multiple myeloma (MM) is a cancer that occurs in plasma cells, which fall under the category of white blood cells that are in charge of antibody production. According to previous studies, microRNA-497 (miR-497) functions as a tumor suppressor in several types of cancer, including gastric cancer and colorectal cancer. Therefore, the present study aims to investigate the effects of miR-497 on cellular function of human MM cells through the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway by targeting Raf-1. The differentially expressed genes and miRs in MM, and the relationship between the miR and gene were verified. It was found that Raf-1 was a target gene of miR-497. The data obtained from MM tissues showed increased Raf-1 level and decreased miR-497 level. MM cells were treated with mimic, inhibitor and siRNA in order to evaluate the role of miR-497, Raf-1 and MAPK/ERK in MM. The expression pattern of miR-497, Raf-1, ERK1/2, survivin, B-cell lymphoma-2 (Bcl-2) and BCL2-Associated X (Bax) as well as the extent of ERK1/2 phosphorylation were determined. Retored miR-497 and si-Raf-1 resulted in increases in the Bax expression and cell apoptosis and decreases in the expressions of Raf-1, MEK-2, survivin, Bcl-2, along with the extent of ERK1/2 phosphorylation. In addition, the biological function evaluations of MM cells revealed that miR-497 mimic or si-Raf-1 led to suppression in cell proliferation, invasion and migration. In conclusion, our results have demonstrated that miR-497 targets Raf-1 in order to inhibit the progression of MM by blocking the MAPK/ERK signaling pathway.

Montelukast enhances cytocidal effects of carfilzomib in multiple myeloma by inhibiting mTOR pathway

Montelukast is an anti-asthmatic medication, and has recently showed its inhibitory effects on the proliferation of cancers. The purpose of this study was to identify the cytotoxic effects of montelukast on multiple myeloma (MM) cells and the combination effects of montelukast and carfilzomib in the treatment of MM. Results revealed that montelukast induced a dose- and time-dependent cytotoxicity in MM cells lines and significantly suppressed the colony formation of myeloma cells. Furthermore, montelukast enhanced the cytotoxicity of carfilzomib in MM cell lines. This anti-tumor effect was associated with decreased c-Myc via the inhibition of mTOR signaling pathway. Moreover, the combination of montelukast and carfilzomib induced apoptosis of myeloma cells effectively, even in the presence of bone marrow stromal cells (BMSCs). It is more important to note that the co-treatment exhibited similar cytocidal effects in carfilzomib-resistant cell lines (U266R and 8226R). In addition, the combined effects were noted in two MM xenograft mice models and 7 cases of human CD138⁺ myeloma cells (4 newly diagnosed cases and 3 relapsed cases) with no cytotoxicity on peripheral blood mononuclear cells (PBMCs) from 5 healthy donors. Our data suggested that montelukast enhanced the cytotoxicity of carfilzomib in both carfilzomib-sensitive and carfilzomib-resistant MM cell lines. These findings may facilitate the development of therapeutic strategies and provide a promising therapeutic combination regimen for the treatment of refractory myeloma.

Survivin expression modulates the sensitivity of A549 lung cancer cells resistance to vincristine

Lung cancer is the leading cause of cancer-associated mortalities worldwide. Chemotherapeutic drug vincristine is widely used to treat lung cancer; however, the acquisition of drug resistance is the major limitation of chemotherapy, and it is thus important to determine the mechanism underlying vincristine resistance in lung cancer. Survivin has been reported to be associated with the development of drug resistance and be involved in the progression of non-small cell lung cancer. In the present study, a vincristine-resistant lung cancer cell line, A549/VCR, was used to investigate the possible involvement of survivin in the acquisition of vincristine resistance. Western blot analysis demonstrated that survivin protein expression level was markedly higher in A549/VCR cells compared with in control A549 cells, whereas p53 expression level was lower in A549/VCR cells compared with in A549 cells. Thus, wild-type p53 was overexpressed in A549/VCR cells and it reversed vincristine resistance of A549/VCR cells via the inhibition of survivin expression. Furthermore, survivin was knocked down by small interfering RNA technology and the effects on viability and apoptosis of resistant cells were investigated. MTT, Annexin V-fluorescein isothiocyanate/propidium iodide and caspase-3 activity assays indicated that survivin silencing significantly inhibited cell viability and enhanced apoptosis induced by vincristine treatment in A549/VCR cells compared with non-silenced A549/VCR cells. These results suggested that survivin expression regulated by p53 may serve an important role in drug resistance in A549/VCR cells and may be a potential target for enhancing vincristine sensitivity in A549 lung cancer cells. Additionally, the present study revealed that A549/VCR cells exhibited cross resistance to methotrexate (MTX) and survivin silencing re-sensitized A549/VCR cells to MTX, indicating the crucial role of survivin in regulating A549 cells sensitivity to anticancer drugs. The results of the present study are significant for determining the underlying mechanism of vincristine resistance in lung cancer.

Growth inhibition and chemo-radiosensitization of esophageal squamous cell carcinoma by survivin-shRNA lentivirus transfection

Esophageal cancer is one of the most common types of cancer worldwide, and it has a poor prognosis. Chemo-radiotherapy resistance and cancer relapse are among the most difficult issues in its treatment. Identifying the underlying molecular mechanisms is critical for developing novel therapies. Survivin has been previously suggested to be overexpressed in esophageal cancer cells. The present study identified that down-regulation of survivin sensitized esophageal cancer cells to chemo-radiotherapy. Consistent with previous studies, the present study indicated that survivin was overexpressed in 4 esophageal squamous carcinoma cell lines. Short hairpin RNA delivered by lentivirus successfully knocked down survivin in these cancer cell lines. Consequently, down-regulation of survivin impaired their colony-forming, migratory and invasive capabilities, while the overexpression of survivin in normal human esophagus epithelial cells improved their resistance to cisplatin, paclitaxel and radiation. Survivin knockdown induced apoptosis in esophageal cancer KYSE-150 and ECA-109 cell lines when exposed to the aforementioned chemo-radiotherapy treatments. These results indicate that survivin expression sustains growth in esophageal cancer cells, and confers resistance to chemo-radiotherapy. Targeted survivin ablation may be a promising strategy against esophageal tumor relapse and chemo-radioresistance.

The Lipid Side of Bone Marrow Adipocytes: How Tumor Cells Adapt and Survive in Bone

PURPOSE OF REVIEW

Bone marrow adipocytes have emerged in recent years as key contributors to metastatic progression in bone. In this review, we focus specifically on their role as the suppliers of lipids and discuss pro-survival pathways that are closely linked to lipid metabolism, affected by the adipocyte-tumor cell interactions, and likely impacting the ability of the tumor cell to thrive in bone marrow space and evade therapy.

RECENT FINDINGS

The combined in silico, pre-clinical, and clinical evidence shows that in adipocyte-rich tissues such as bone marrow, tumor cells rely on exogenous lipids for regulation of cellular energetics and adaptation to harsh metabolic conditions of the metastatic niche. Adipocyte-supplied lipids have a potential to alter the cell's metabolic decisions by regulating glycolysis and respiration, fatty acid oxidation, lipid desaturation, and PPAR signaling. The downstream effects of lipid signaling on mitochondrial homeostasis ultimately control life vs. death decisions, providing a mechanism for gaining survival advantage and reduced sensitivity to treatment. There is a need for future research directed towards identifying the key metabolic and signaling pathways that regulate tumor dependence on exogenous lipids and consequently drive the pro-survival behavior in the bone marrow niche.

Inhibitors of apoptosis: clinical implications in cancer

Inhibitor of apoptosis (IAP) family comprises a group of endogenous proteins that function as main regulators of caspase activity and cell death. They are considered the main culprits in evasion of apoptosis, which is a fundamental hallmark of carcinogenesis. Overexpression of IAP proteins has been documented in various solid and hematological malignancies, rendering them resistant to standard chemotherapeutics and radiation therapy and conferring poor prognosis. This observation has urged their exploitation as therapeutic targets in cancer with promising pre-clinical outcomes. This review describes the structural and functional features of IAP proteins to elucidate the mechanism of their anti-apoptotic activity. We also provide an update on patterns of IAP expression in different tumors, their impact on treatment response and prognosis, as well as the emerging investigational drugs targeting them. This aims at shedding the light on the advances in IAP targeting achieved to date, and encourage further development of clinically applicable therapeutic approaches.

The novel compound STK405759 is a microtubule-targeting agent with potent and selective cytotoxicity against multiple myeloma in vitro and in vivo

Despite advances in treatment, multiple myeloma (MM) remains incurable. Here we propose the use of STK405759, a novel microtubule targeting agent (MTA) and member of the furan metotica family for MM therapy.

STK405759 inhibited tubulin polymerization in a cell-free system and in myeloma cells. This molecule had potent cytotoxic activity against several MM cell lines and patient-derived MM cells. Moreover, STK405759 demonstrated cytotoxicity against drug-resistant myeloma cells that overexpressed the P-glycoprotein drug-efflux pump. STK405759 was not cytotoxic to peripheral blood mononuclear cells, including activated B and T lymphocytes. This compound caused mitotic arrest and apoptosis of myeloma cells characterized by cleavage of poly (ADP-ribose) polymerase-1 and caspase-8, as well as decreased protein expression of mcl-1. The combination of STK405759 with bortezomib, lenalidomide or dexamethasone had synergistic cytotoxic activity. In in vivo studies, STK405759-treated mice had significantly decreased MM tumor burden and prolonged survival compared to vehicle treated- mice.

These results provide a rationale for further evaluation of STK405759 as monotherapy or part of combination therapy for treating patients with MM.

Bavachin induces the apoptosis of multiple myeloma cell lines by inhibiting the activation of nuclear factor kappa B and signal transducer and activator of transcription 3

Bavachin is a phytoestrogen purified from natural herbal plants such as Psoralea corylifolia. In this study, we examined the effect of bavachin in multiple myeloma (MM) cell lines. We found that bavachin decreased the viability of MM cell lines, but was not cytotoxic towards normal cells. It inhibited the activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3). Furthermore, bavachin increased the expression of p53 and NOXA, and decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, B cell lymphoma-extra large (Bcl-xL), and Bcl-2. Additionally, bavachin induced apoptosis by the activation of caspase-3 and caspase-9, implicating the involvement of the mitochondrial pathway. Our results suggest that bavachin induces apoptosis through the inhibition of NF-κB and STAT3 activation in MM cell lines. Most importantly, few NF-κB and STAT3 inhibitors with high efficiency, specificity, and safety are currently available for clinical cancer therapy. Hence, bavachin, which targets NF-κB and STAT3, is a potential anticancer agent for the treatment of MM.

Modeling multiple myeloma-bone marrow interactions and response to drugs in a 3D surrogate microenvironment

Multiple myeloma develops primarily inside the bone marrow microenvironment, that confers pro-survival signals and drug resistance. 3D cultures that reproduce multiple myeloma-bone marrow interactions are needed to fully investigate multiple myeloma pathogenesis and response to drugs. To this purpose, we exploited the 3D Rotary Cell Culture System bioreactor technology for myeloma-bone marrow co-cultures in gelatin scaffolds. The model was validated with myeloma cell lines that, as assessed by histochemical and electron-microscopic analyses, engaged contacts with stromal cells and endothelial cells. Consistently, pro-survival signaling and also cell adhesion-mediated drug resistance were significantly higher in 3D than in 2D parallel co-cultures. The contribution of the VLA-4/VCAM1 pathway to resistance to bortezomib was modeled by the use of VCAM1 transfectants. Soluble factor-mediated drug resistance could be also demonstrated in both 2D and 3D co-cultures. The system was then successfully applied to co-cultures of primary myeloma cells-primary myeloma bone marrow stromal cells from patients and endothelial cells, allowing the development of functional myeloma-stroma interactions and MM cell long-term survival. Significantly, genomic analysis performed in a high-risk myeloma patient demonstrated that culture in bioreactor paralleled the expansion of the clone that ultimately dominated in vivo. Finally, the impact of bortezomib on myeloma cells and on specialized functions of the microenvironment could be evaluated. Our findings indicate that 3D dynamic culture of reconstructed human multiple myeloma microenvironments in bioreactor may represent a useful platform for drug testing and for studying tumor-stroma molecular interactions.

MicroRNA‑320 targets mitogen‑activated protein kinase 1 to inhibit cell proliferation and invasion in epithelial ovarian cancer

Ovarian cancer is the second most frequently occurring cancer and the most fatal gynecological malignancy of all gynecological cancers worldwide. MicroRNAs (miR) have been reported to be downregulated or upregulated in a variety of human malignancies, and involved in the formation and progression of the majority of human cancers, including epithelial ovarian cancer (EOC). miR‑320 has been identified as a tumor suppressor in multiple human cancers. However, the expression levels, biological role and underlying mechanisms of miR‑320 in EOC remain to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑320 expression in EOC tissues and cell lines. Following transfection with miR‑320 mimics, Cell Counting Kit 8 and cell invasion assays were utilized to investigate the effects of miR‑320 on EOC cell proliferation and invasion. Bioinformatic analysis, luciferase reporter assay, RT‑qPCR and western blotting were used to explore the underlying mechanism of how miR‑320 affects cell proliferation and invasion in EOC. Mitogen‑activated protein kinase (MAPK) 1 expression and its association with the miR‑320 expression level was examined in EOC tissues. The role of MAPK1 in EOC cells was additionally evaluated by using a loss‑of‑function assay. The results demonstrated that miR‑320 was markedly downregulated in EOC tissues and cell lines. A decreased miR‑320 expression was significantly correlated with the Federation of Gynecology and Obstetrics stage and lymph node metastasis of EOC patients. Additionally, reintroduction of miR‑320 expression suppressed cell proliferation and invasion in EOC. Furthermore, it was verified that MAPK1 is a direct target gene of miR‑320 in EOC. MAPK1 expression was markedly upregulated in EOC tissues and inversely correlated with miR‑320 expression. Furthermore, silencing of MAPK1 by RNA interference inhibited cell proliferation and invasion of EOC cells. Overall, the present study demonstrated that miR‑320 may act as a useful diagnostic and therapeutic target in the treatment of EOC.

The MIP-1α autocrine loop contributes to decreased sensitivity to anticancer drugs

Several autocrine soluble factors, including macrophage inflammatory protein-1α (MIP-1α), tumor necrosis factor-α, and hepatocyte growth factor, promote cell survival and growth in multiple myeloma (MM) cells. We hypothesized that inhibition of the MIP-1α autocrine loop may enhance the cytotoxic effect of anticancer drugs in MM cell lines. In the present study, an MIP-1α neutralizing antibody suppressed cell proliferation and enhanced the cytotoxic effect of melphalan or bortezomib on MM cells. In addition, melphalan resistance cells (RPMI8226/L-PAM and HS-sultan/L-PAM cells) secreted MIP-1α and neutralizing antibody of MIP-1α partially overcame melphalan resistance. Moreover, combination treatment with MIP-1α neutralizing antibody and melphalan or bortezomib inhibited extracellular signal regulated kinase 1/2 (ERK1/2), Akt, and mammalian target of rapamycin (mTOR) activation, Bcl-2, Bcl-xL, and Survivin expression, and upregulated the expression of Bim and cleaved Poly (ADP-ribose) polymerase (PARP). Treatment of IM9 cells with MIP-1α siRNA suppressed the activation of ERK1/2, Akt, and mTOR, and enhanced the cytotoxic effect of melphalan and bortezomib. These results indicate that MIP-1α neutralizing antibodies or MIP-1α siRNA enhance the cytotoxic effect of melphalan and bortezomib by suppressing the chemokine receptor/ERK and chemokine receptor/Akt/mTOR pathways. The inhibition of MIP-1α may thus provide a new therapeutic approach to control tumor progression and bone destruction in patients with MM.

Targeting phosphorylation of STAT3 delays tumor growth in HPV-negative anal squamous cell carcinoma mouse model

Although conventional chemoradiotherapy is effective for most anal squamous cell carcinoma (ASCC) patients, HPV-negative ASCC patients respond poorly to this treatment and new therapeutic approach is required. Our group has previously established an HPV-negative ASCC mouse model and demonstrated that signal transducer and activation of transcription 3 (STAT3) is hyper-activated in the model. Here, we show that in vivo inhibition of STAT3 by S3I-201 effectively delays tumor growth in ASCC mouse model indicated by significantly smaller tumor size and burden in the treatment group compared with control group at the same point. Further analysis shows that survivin and Ki67, important biomarkers for tumor cell survival and proliferation, are significantly reduced after S3I-201 treatment. Additionally, flow cytometry and immunohistofluorescent assays reveal decreased Myeloid-derived suppressor cell (MDSC) and tumor-associated macrophage (TAM) populations in the S3I-201 treatment group, which indicates a reversion of the immunosuppressive environment, unraveling the potential role for S3I-201 in immunosuppression in ASCC. Together these results for the first time demonstrated the anti-tumor effects of STAT3 inhibitor S3I-201 in HPV-negative ASCC mouse model and its multiple effects on cancer cells and immune system. Thus we conclude that S3I-201 may be a novel therapeutic approach for HPV-negative ASCC patients.

BRCA1 expression serves a role in vincristine resistance in colon cancer cells

The present study aimed to investigate the association between breast cancer susceptibility gene 1 (BRCA1) expression and drug resistance in colon cancer, with the specific aim of elucidating the underlying molecular mechanisms of vincristine (VCR) resistance in tumor cells. The HCT-8 human colon cancer cell line was used to establish the VCR-resistant HCT-8/V line by gradually increasing the concentration of VCR during cell culture. The relative mRNA and protein expression levels of BRCA1 in these colon cancer cell lines was assessed by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) analysis and western blotting, respectively. Resistance to VCR was established in the HCT-8/V colon cancer cells, and RT-qPCR and western blot analysis revealed the expression of BRCA1 to be significantly higher in the VCR-resistant cells compared with their drug-sensitive counterparts (P<0.05). The decreased BRCA1 expression in these VCR-resistant cells may be associated with the drug resistance frequently observed in colon cancer.

MicroRNA-329-3p targets MAPK1 to suppress cell proliferation, migration and invasion in cervical cancer

Cervical cancer is the second most common gynecological cancer worldwide and remains as one of the leading causes of cancer-related death among women. Despite great progress in the treatment of cervical cancer, the 5-year overall survival rate for patients with this disease remains unsatisfactory. Over the past decade, an increasing number of studies indicate a central role for microRNAs in the initiation and progression of cervical cancer. microRNA‑329-3p (miR-329-3p) has been studied in many types of human cancer; however, the expression level, biological role and the underlying mechanism of miR-329-3p in cervical cancer has not yet been investigated. In the present study, we found that the expression levels of miR-329-3p were reduced in both cervical cancer tissues and cell lines. Low miR-329-3p expression was negatively correlated with histological grade, International Federation of Gynecology and Obstetrics (FIGO) stage, and lymph node metastasis of cervical cancer patients. In addition, upregulation of miR‑329-3p suppressed cell proliferation, migration and invasion of cervical cancer. Furthermore, MAPK1 was identified as a direct target gene of miR-329-3p. MAPK1 was significantly upregulated in cervical cancer tissues and was inversely correlated with miR-329-3p expression in the cervical cancer tissues. Silencing of MAPK1 by RNA interference mimicked the effects of miR-329-3p overexpression on cell proliferation, migration and invasion in cervical cancer. Moreover, rescue experiments showed that restoration of the expression of MAPK1 reversed the effects of miR‑329-3p overexpression in cervical cancer cells. Taken together, these findings suggest that miR-329-3p has a critical tumor-suppressive roles by directly targeting MAPK1 in cervical cancer, and it may be investigated as a novel therapeutic target for the treatment of patients with this disease.

Synthesis and Antiproliferative Activity of Novel All-Trans-Retinoic Acid-Podophyllotoxin Conjugate towards Human Gastric Cancer Cells

With the purpose of creating a multifunctional drug for gastric cancer treatment, a novel all-trans-retinoic acid (ATRA) conjugate with podophyllotoxin (PPT) was designed and synthesized, and its in vitro antiproliferative activity was evaluated against human gastric cancer cell lines using CCK-8 assay. The conjugate, P-A, exhibited significant anticancer activity against MKN-45 and BGC-823 cells with IC₅₀ values of 0.419 ± 0.032 and 0.202 ± 0.055 μM, respectively. Moreover, P-A efficiently triggered cell cycle arrest and induced apoptosis in MKN-45 and BGC-823 cells due to modulation of cell cycle arrest- (CDK1, CDK2, CyclinA and CyclinB1) and apoptosis- (cleaved caspase-3, -8 and -9) related proteins, respectively. Further mechanism studies revealed that P-A could increase the expression levels of RARα and RARβ, and decrease the level of RARγ in MKN-45 and BGC-823 cells. Finally, P-A inhibited the ERK1/2 and AKT signaling in the above two cancer cell lines. More importantly, the underlying mechanisms of P-A were similar to those of precursor PPT but different with the other precursor ATRA. Together, the conjugate P-A was a promising candidate for the potential treatment of human gastric cancer.

Meta-analysis of gene expression in relapsed childhood B-acute lymphoblastic leukemia

Background

Relapsed pediatric B-acute lymphoblastic leukemia (B-ALL) remains as the leading cause of cancer death among children. Other than stem cell transplantation and intensified chemotherapy, no other improved treatment strategies have been approved clinically. Gene expression profiling represents a powerful approach to identify potential biomarkers and new therapeutic targets for various diseases including leukemias. However, inadequate sample size in many individual experiments has failed to provide adequate study power to yield translatable findings. With the hope of getting new insights into the biological mechanisms underpinning relapsed ALL and identifying more promising biomarkers or therapeutic targets, we conducted a meta-analysis of gene expression studies involving ALL from 3 separate studies.

Method

By using the keywords “acute lymphoblastic leukemia”, and “microarray”, a total of 280 and 275 microarray datasets were found listed in Gene Expression Omnibus database GEO and ArrayExpress database respectively. Further manual inspection found that only three studies (GSE18497, GSE28460, GSE3910) were focused on gene expression profiling of paired diagnosis-relapsed pediatric B-ALL. These three datasets which comprised of a total of 108 matched diagnosis-relapsed pediatric B-ALL samples were then included for this meta-analysis using RankProd approach.

Results

Our analysis identified a total of 1795 upregulated probes which corresponded to 1527 genes (pfp < 0.01; FC > 1), and 1493 downregulated probes which corresponded to 1214 genes (pfp < 0.01; FC < 1) respectively. S100A8 appeared as the top most overexpressed gene (pfp < 0.01, FC = 1.8) and is a potential target for further validation. Based on gene ontology biological process annotation, the upregulated genes were most enriched in cell cycle processes (enrichment score = 15.3), whilst the downregulated genes were clustered in transcription regulation (enrichment score = 12.6). Elevated expression of cell cycle regulators (e.g kinesins, AURKA, CDKs) was the key genetic defect implicated in relapsed ALL, and serve as attractive targets for therapeutic intervention.

Conclusion

We identified S100A8 as the most overexpressed gene, and the cell cycle pathway as the most promising biomarker and therapeutic target for relapsed childhood B-ALL. The validity of the results warrants further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3103-1) contains supplementary material, which is available to authorized users.

MicroRNA-141 enhances anoikis resistance in metastatic progression of ovarian cancer through targeting KLF12/Sp1/survivin axis

BACKGROUND

Cancer metastasis is determined by the formation of the metastatic niche and the ability of cancer cells to adapt to microenvironmental stresses. Anoikis resistance is a fundamental feature of metastatic cancer cell survival during metastatic cancer progression. However, the mechanisms underlying anoikis resistance in ovarian cancer are still unclear.

METHODS

Expressions of miRNA-141 and its downstream targets were evaluated by qPCR, Western blotting, Immunohistochemical (IHC) and in situ hybridization (ISH) assays. The luciferase assays were used to prove KLF12 as the downstream target of miR-141. The cDNA microarray and apoptotic protein arrays were used to identify the targets of miR-141 and KLF12. The competition of KLF12 and Sp1 on survivin promoter was examined by ChIP assay. IHC analysis on ovarian cancer tissue array was used to evaluate the expressions of KLF12 and miR-141 and to show the clinical relevance. The functional studies were performed by in vitro and in vivo tumorigenic assays.

RESULTS

Enforced expression of miR-141 promotes, while knockdown of miR-141 expression inhibits, cell proliferation, anchorage-independent capacity, anoikis resistance, tumor growth and peritoneal metastases of ovarian cancer cells. Bioinformatics and functional analysis identified that Kruppel-related zinc finger protein AP-2rep (KLF12) is directly targeted by miR-141. Consistent with this finding, knockdown of KLF12 phenocopied the effects of miR-141 overexpression in ovarian cancer cells. In contrast, restoration of KLF12 in miR-141-expressing cells significantly attenuated anoikis resistance in ovarian cancer cells via interfering with Sp1-mediated survivin transcription, which inhibits the intrinsic apoptotic pathway and is crucial for ovarian cancer cell survival, anoikis resistance and peritoneal metastases. Immunohistochemical (IHC) and in situ hybridization (ISH) assays confirmed that miRNA-141 expression is inversely correlated with KLF12 expression and significantly associated with advanced ovarian cancers accompanied with distal metastases, underscoring the clinical relevance of our findings.

CONCLUSIONS

Our data identify a novel signaling axis of miR-141/KLF12/Sp1/survivin in enhancing anoikis resistance and likely serves as a potential therapeutic target for metastatic ovarian cancer.

Chikusetsusaponin IVa methyl ester induces G1 cell cycle arrest, triggers apoptosis and inhibits migration and invasion in ovarian cancer cells

BACKGROUND

Panacis Japonici Rhizoma (PJR) is one of the most famous Chinese medical herbs that is known for exhibiting potential anti-cancer effects.

PURPOSE

This study aims to isolate and investigate the anti-cancer potential of saponins from PJR in ovarian cancer cells.

METHODS

The compounds were separated by comprehensive chromatographic methods. By comparison of the 1H- and 13C NMR data, as well as the HR-ESI-MS data, with the corresponding references, the structures of compounds were determined. MTT assay was performed to evaluate cell viability, along with flow cytometry for cell cycle analysis. JC-1 staining, Annexin V-PI double staining as well as Hoechst 33; 342 staining were used for detecting cell apoptosis. Western blot analysis was conducted to determine the relative protein level. Transwell assays were performed to investigate the effect of the saponin on cell migration and invasion and zymography experiments were used to detect the enzymatic activities.

RESULTS

Eleven saponins were isolated from PJR and their anti-proliferative effects were evaluated in human ovarian cancer cells. Chikusetsusaponin IVa methyl ester (1) exhibited the highest anti-proliferative potential among these isolates with the IC50 values at less than 10 µM in both ovarian cancer A2780 and HEY cell lines. Compound 1 induced G1 cell cycle arrest accompanied with an S phase decrease, and down-regulated the expression of cyclin D1, CDK2, and CDK6. Further study showed that compound 1 effectively decreased the cell mitochondrial membrane potential, increased the annexin V positive cells and nuclear chromatin condensation, as well as enhanced the expression of cleaved PARP, Bax and cleaved-caspase 3 while decreasing that of Bcl-2. Moreover, compound 1 suppressed the migration and invasion of HEY and A2780 cells, down-regulated the expression of Cdc42, Rac, RohA, MMP2 and MMP9, and decreased the enzymatic activities of MMP2 and MMP9.

CONCLUSION

These results provide a comprehensive evaluation of compound 1 as a potential agent for the treatment of ovarian cancer.

Autophagy and its implication in human oral diseases

Macroautophagy/autophagy is a conserved lysosomal degradation process essential for cell physiology and human health. By regulating apoptosis, inflammation, pathogen clearance, immune response and other cellular processes, autophagy acts as a modulator of pathogenesis and is a potential therapeutic target in diverse diseases. With regard to oral disease, autophagy can be problematic either when it is activated or impaired, because this process is involved in diverse functions, depending on the specific disease and its level of progression. In particular, activated autophagy functions as a cytoprotective mechanism under environmental stress conditions, which regulates tumor growth and mediates resistance to anticancer treatment in established tumors. During infections and inflammation, activated autophagy selectively delivers microbial antigens to the immune systems, and is therefore connected to the elimination of intracellular pathogens. Impaired autophagy contributes to oxidative stress, genomic instability, chronic tissue damage, inflammation and tumorigenesis, and is involved in aberrant bacterial clearance and immune priming. Hence, substantial progress in the study of autophagy provides new insights into the pathogenesis of oral diseases. This review outlines the mechanisms of autophagy, and highlights the emerging roles of this process in oral cancer, periapical lesions, periodontal diseases, and oral candidiasis.

Overexpression of suppressor of IKBKE 1 is associated with vincristine resistance in colon cancer cells

In a previous study, the suppressor of IKBKE 1 expression level was confirmed to be higher in vincristine (VCR)-resistant HCT-8 (HCT-8/V) colon cancer cells than in non-VCR-resistant HCT-8 cells. In the current study, IKBKE 1 expression in VCR-resistant colon cancer cells was investigated further. HCT-8 and HCT-8/V human colon cancer cells were used, and polymerase chain reaction (PCR) primers were designed to amplify the IKBKE 1 gene. Fluorescence reverse transcription-quantitative PCR (RT-qPCR) was performed to detect differences in IKBKE 1 expression between sensitive and drug-resistant colon cancer cell lines. Western blotting was performed to further observe IKBKE 1 expression. Based on the RT-qPCR and western blot results, IKBKE 1 expression was observed to be markedly higher in the HCT-8/V cells, and this difference was significant (P<0.05). Thus, IKBKE 1 expression was identified to be associated with the resistance of colon cancer cells to VCR.

MiR-34a and miR-203 Inhibit Survivin Expression to Control Cell Proliferation and Survival in Human Osteosarcoma Cells

Elevated expression of survivin is observed in a number of cancer types, including human osteosarcoma. Few studies have demonstrated that survivin expression levels can be considered an independent predictor of survival for human osteosarcoma patients. However, the underlying molecular mechanisms of survivin in the process of human osteosarcoma carcinogenesis remain unclear. In the current study, we evaluated the biological effects of survivin knockdown on osteosarcoma cell proliferation, colony formation rate, and sensitivity to the chemotherapeutic agent cisplatin. We found that two different osteosarcoma cell lines, U2OS and Saos-2, have relatively higher expression levels of survivin, and specific knockdown of survivin resulted in a number of effects, such as inhibition of cell proliferation, decreased colony formation rate, cell cycle arrest at G2/M phase, induction of apoptosis, and increased sensitivity to cisplatin. In addition, we identified two microRNAs, miR-34a and miR-203, that are aberrantly expressed in human osteosarcoma cells and specifically target survivin by inhibiting its expression, therefore repressing osteosarcoma cell maintenance and proliferation.

Mangiferin enhances the sensitivity of human multiple myeloma cells to anticancer drugs through suppression of the nuclear factor κB pathway

Multiple myeloma (MM) is still an incurable hematological malignancy with a 5-year survival rate of ~35%, despite the use of various treatment options. The nuclear factor κB (NF-κB) pathway plays a crucial role in the pathogenesis of MM. Thus, inhibition of the NF-κB pathway is a potential target for the treatment of MM. In a previous study, we showed that mangiferin suppressed the nuclear translocation of NF-κB. However, the treatment of MM involves a combination of two or three drugs. In this study, we examined the effect of the combination of mangiferin and conventional anticancer drugs in an MM cell line. We showed that the combination of mangiferin and an anticancer drug decreased the viability of MM cell lines in comparison with each drug used separately. The decrease in the combination of mangiferin and an anticancer drug induced cell viability was attributed to increase the expression of p53 and Noxa and decreases the expression of XIAP, survivin, and Bcl-xL proteins via inhibition of NF-κB pathway. In addition, the combination treatment caused the induction of apoptosis, activation of caspase-3 and the accumulation of the cells in the sub-G1 phase of the cell cycle. Our findings suggest that the combination of mangiferin and an anticancer drug could be used as a new regime for the treatment of MM.

Mangiferin induces apoptosis in multiple myeloma cell lines by suppressing the activation of nuclear factor kappa B-inducing kinase

Mangiferin is a naturally occurring glucosyl xanthone, which induces apoptosis in various cancer cells. However, the molecular mechanism underlying mangiferin-induced apoptosis has not been clarified thus far. Therefore, we examined the molecular mechanism underlying mangiferin-induced apoptosis in multiple myeloma (MM) cell lines. We found that mangiferin decreased the viability of MM cell lines in a concentration-dependent manner. We also observed an increased number of apoptotic cells, caspase-3 activation, and a decrease in the mitochondrial membrane potential. In addition, mangiferin inhibited the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated inhibitor kappa B (IκB) and increased the expression of IκB protein, whereas no changes were observed in the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase 1/2 (JNK1/2), and mammalian target of rapamycin (mTOR). The molecular mechanism responsible for mangiferin-induced inhibition of nuclear translocation of NF-κB was a decrease in the expression of phosphorylated NF-κB-inducing kinase (NIK). Moreover, mangiferin decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, and Bcl-xL proteins. Knockdown of NIK expression showed results similar to those observed with mangiferin treatment. Our results suggest that mangiferin induces apoptosis through the inhibition of nuclear translocation of NF-κB by suppressing NIK activation in MM cell lines. Our results provide a new insight into the molecular mechanism of mangiferin-induced apoptosis. Importantly, since the number of reported NIK inhibitors is limited, mangiferin, which targets NIK, may be a potential anticancer agent for the treatment of MM.

Discovery of New Monocarbonyl Ligustrazine-Curcumin Hybrids for Intervention of Drug-Sensitive and Drug-Resistant Lung Cancer

The elevation of oxidative stress preferentially in cancer cells by inhibiting thioredoxin reductase (TrxR) and/or enhancing reactive oxygen species (ROS) production has emerged as an effective strategy for selectively targeting cancer cells. In this study, we designed and synthesized 21 ligustrazine-curcumin hybrids (10a-u). Biological evaluation indicated that the most active compound 10d significantly inhibited the proliferation of drug-sensitive (A549, SPC-A-1, LTEP-G-2) and drug-resistant (A549/DDP) lung cancer cells but had little effect on nontumor lung epithelial-like cells (HBE). Furthermore, 10d suppressed the TrxR/Trx system and promoted intracellular ROS accumulation and cancer cell apoptosis. Additionally, 10d inhibited the NF-κB, AKT, and ERK signaling, P-gp-mediated efflux of rhodamine 123, P-gp ATPase activity, and P-gp expression in A549/DDP cells. Finally, 10d repressed the growth of implanted human drug-resistant lung cancer in mice. Together, 10d acts a novel TrxR inhibitor and may be a promising candidate for intervention of lung cancer.