p38 MAPK-induced MDM2 degradation confers paclitaxel resistance through p53-mediated regulation of EGFR in human lung cancer cells

Cancer chemoprevention: signaling pathways and strategic approaches

Although cancer chemopreventive agents have been confirmed to effectively protect high-risk populations from cancer invasion or recurrence, only over ten drugs have been approved by the U.S. Food and Drug Administration. Therefore, screening potent cancer chemopreventive agents is crucial to reduce the constantly increasing incidence and mortality rate of cancer. Considering the lengthy prevention process, an ideal chemopreventive agent should be nontoxic, inexpensive, and oral. Natural compounds have become a natural treasure reservoir for cancer chemoprevention because of their superior ease of availability, cost-effectiveness, and safety. The benefits of natural compounds as chemopreventive agents in cancer prevention have been confirmed in various studies. In light of this, the present review is intended to fully delineate the entire scope of cancer chemoprevention, and primarily focuses on various aspects of cancer chemoprevention based on natural compounds, specifically focusing on the mechanism of action of natural compounds in cancer prevention, and discussing in detail how they exert cancer prevention effects by affecting classical signaling pathways, immune checkpoints, and gut microbiome. We also introduce novel cancer chemoprevention strategies and summarize the role of natural compounds in improving chemotherapy regimens. Furthermore, we describe strategies for discovering anticancer compounds with low abundance and high activity, revealing the broad prospects of natural compounds in drug discovery for cancer chemoprevention. Moreover, we associate cancer chemoprevention with precision medicine, and discuss the challenges encountered in cancer chemoprevention. Finally, we emphasize the transformative potential of natural compounds in advancing the field of cancer chemoprevention and their ability to introduce more effective and less toxic preventive options for oncology.

The ubiquitin-proteasome system in the regulation of tumor dormancy and recurrence

Tumor recurrence is a mechanism triggered in sparse populations of cancer cells that usually remain in a quiescent state after strict stress and/or therapeutic factors, which is affected by a variety of autocrine and microenvironmental cues. Despite thorough investigations, the biology of dormant and/or cancer stem cells is still not fully elucidated, as for the mechanisms of their reawakening, while only the major molecular patterns driving the relapse process have been identified to date. These molecular patterns profoundly interfere with the elements of cellular proteostasis systems that support the efficiency of the recurrence process. As a major proteostasis machinery, we review the role of the ubiquitin-proteasome system (UPS) in tumor cell dormancy and reawakening, devoting particular attention to the functions of its components, E3 ligases, deubiquitinating enzymes and proteasomes in cancer recurrence. We demonstrate how UPS components functionally or mechanistically interact with the pivotal proteins implicated in the recurrence program and reveal that modulators of the UPS hold promise to become an efficient adjuvant therapy for eradicating refractory tumor cells to impede tumor relapse.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Resveratrol augments paclitaxel sensitivity by modulating miR-671-5p/STOML2/PINK1/Parkin-mediated autophagy signaling in A549 cell

BACKGROUND

Paclitaxel (PTX) resistance has become a notable clinical concern of Non-small cell lung cancer (NSCLC). Our study aim is to investigate the effects of Resveratrol (RES) on NSCLC cells that have developed resistance to PTX. The NSCLC cell line A549 was employed in this investigation to establish a PTX-resistant NSCLC cell line, denoted as A549/PTX, and established tumor transplantaton model. The presence of miR-671-5p, Stomatin-like protein 2 (STOML2), and mitophagy biomarkers was evaluated using quantitative teal-time PCR (qRT-PCR) and western blot, The assessment of cell proliferation and apoptosis was conducted through the utilisation of colony formation and flow cytometry assays. The investigation of mitochondrial autolysosomes was conducted using transmission electron microscopy (TEM). Our results showed that the application of RES therapy resulted in a substantial improvement in the sansitivity of A549/PTX cells. RES exhibited an augmentation of apoptosis and a suppression of mitophagy in A549/PTX cells. RES induced an upregulation in the expression of miR-671-5p. This, in turn, leaded to the inhibition of STOML2, a protein that directly interacts with PINK1. In summary, our research indicates that RES improved the susceptibility of A549/PTX cells to PTX through miR-671-5p-mediated STOML2 inhibition.

Gemcitabine: An Alternative Treatment for Oxaliplatin-Resistant Colorectal Cancer

Resistance to treatments is one of the leading causes of cancer therapy failure. Oxaliplatin is a standard chemotherapy used to treat metastatic colorectal cancer. However, its efficacy is greatly reduced by the development of resistances. In a previous study, we deciphered the mechanisms leading to oxaliplatin resistance and highlighted the roles played by ROS production and the p38 MAPK pathway in this phenomenon. In this report, we studied the effects of different chemotherapy molecules on our oxaliplatin-resistant cells to identify alternative treatments. Among all the studied molecules, gemcitabine was the only one to present a major cytotoxic effect on oxaliplatin-resistant cancer cells both in vivo and in vitro. However, the combination of oxaliplatin and gemcitabine did not present any major interest. Indeed, the study of combination efficiency using Chou and Talalay's method showed no synergy between oxaliplatin and gemcitabine. Using PamGene technology to decipher gemcitabine's effects on oxaliplatin-resistant cells, we were able to show that gemcitabine counteracts chemoresistance by strongly inhibiting the Akt and src/p38 MAPK pathways, leading to apoptosis induction and cell death. In view of these results, gemcitabine could be an interesting alternative therapy for patients with colorectal cancer not responding to oxaliplatin-based protocols such as FOLFOX.

Hydrogen gas post-conditioning alleviates cognitive dysfunction and anxiety-like behavior in a rat model of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) results in high rates of mortality and lasting disability. Hydrogen gas (H2) is an antioxidant with demonstrated neuroprotective efficacy. The present study examined the therapeutic efficacy of H2 inhalation on early brain injury following experimental SAH in rats and the potential underlying molecular mechanisms. The rats were randomly separated into three groups (n=36 per group): Sham, SAH and SAH + H2. Endovascular perforation of the right internal carotid artery was used to establish SAH. After perforation, rats in the SAH + H2 group inhaled 2.9% H2 with regular oxygen for 2 h. Then, 24 h post-SAH, TUNEL staining was used to detect apoptotic neurons, and both immunostaining and western blotting were conducted to examine changes in p38 MAPK activity and the expression levels of apoptotic regulators (Bcl-2, Bax and cleaved caspase-3) in the ventromedial prefrontal cortex. Then, 30 day post-SAH, Nissl staining was performed to detect neuronal injury, brain MRI was conducted to detect gross changes in brain structure and metabolism, the open field test was used to assess anxiety and the novel object recognition test was performed to assess memory. H2 inhalation following experimental SAH stabilized brain metabolites, improved recognition memory and reduced anxiety-like behavior, the neuronal apoptosis rate, phosphorylated p38 MAPK expression, cleaved caspase-3 expression and the Bax/Bcl-2 ratio. Collectively, the present results suggested that H2 inhalation can alleviate SAH-induced cognitive impairment, behavioral abnormalities and neuronal apoptosis in rats, possibly via inhibition of the p38 MAPK signal pathway.

Combination Therapy with KRAS and P38α siRNA Suppresses Colorectal Cancer Growth and Development in SW480 Cell Line

PURPOSE

Colorectal cancer (CRC) is one of the most prevalence malignancies in a different society with a high rate of death. The KRAS and p38α axes have critical roles in the development, migration, and growth of numerous tumors, such as colorectal malignancy. KRAS mutation acts as an oncogene in various cancers and is correlated with the poor prognosis in colorectal tumors. Also, p38α plays different roles and exhibits tissue-dependent activity. In some tissues act as an oncogene while in others act as a tumor suppressor. In this research, we try to understand the effect of the P38α and KRAS genes suppression by specific siRNAs on the SW480 cell line progression.

METHODS

We evaluate the impact of the P38α and KRAS gene knockdown by special siRNA on the growth and development of the SW480 cell line. SW480 cell line was treated with KRAS and P38α siRNAs, and the cell viability, gene expression, migration ability, and rate of apoptosis were evaluated with MTT assay, real-time PCR, scratch test, and flow cytometry.

RESULTS

After treatment of the cancer cell with KRAs and P38α siRNAs, cell viability reduced to 29.16%. Also, the expression levels of the KRAS and P38α genes reduced to 26.34% and 16.06%, respectively. Apoptosis rate after combination therapy with KRAS and P38α siRNAs increased to 72.1. Also, we found that these siRNAs suppress cell migration in SW480 cell lines.

CONCLUSION

The current study showed that combination therapy with p38α and KRAS siRNA may be considered a novel therapy for colorectal tumor in future.

Targeting microRNAs by curcumin: implication for cancer therapy

In spite of all the investigations in the past 20 years that established a great body of knowledge in cancer therapy, utilizing some elderly methods such as plant compound administration might still be useful. Curcumin is a bioactive polyphenol, which has many anticancer properties but its capability in modulating miRNA expression has opened new doors in the field of cancer-targeted therapy. MiRNAs are a class of small noncoding RNAs that are able to regulate gene expression and signaling. In addition, some other effects of these RNAs such as modulating cell differentiation and regulation of cell cycle have made miRNAs great candidates for personalized cancer treatment. In this review, we try to find some answers to the questions on how curcumin exerts its impacts on cancer hallmarks through miRNAs and whether chemotherapy can be replaced by this beneficial plant compound.

125I Seed Promotes Apoptosis in Non-small Lung Cancer Cells via the p38 MAPK-MDM2-p53 Signaling Pathway

Purpose: ¹²⁵I seeds were effective in the treatment of non-small cell lung cancer in previous research. However, the exact signaling pathway-mediated apoptosis mechanism is still unclear. The present study analyzed the effects and potential mechanisms of ¹²⁵I seed on the growth and migration of A549 cells. Methods: Lung cancer A549 cells were irradiated with ¹²⁵I seed for various times. MTT, invasion assay, and flow cytometry were used to detect the proliferation, invasion, and apoptosis of treated cells, respectively. A Nimblegen genome-wide expression profile chip was used to evaluate gene expression changes in ¹²⁵I seed-treated A549 cells. Validation studies were performed using phosphorylated protein chip technology, Western blot, nude mouse tumor xenograft assay, and immunohistochemical experiments. All statistical analyses were performed using unpaired Student's t tests and Kruskal-Wallis test. Results: Irradiation with ¹²⁵I seed inhibited A549 cell proliferation and invasion and induced apoptosis (primarily early apoptosis). Irradiation with ¹²⁵I seed also caused the downregulation of p38MAPK, degradation of mouse double-minute 2 homolog (MDM2), and higher expression of p53, which eventually resulted in non-small cell lung cancer cell apoptosis. Conclusion: ¹²⁵I seed irradiation activated the p38MAPK/MDM2/p53 signaling pathway and promoted non-small cell lung cancer cell apoptosis. Future clinical studies targeting this signal may provide a new potential therapeutic approach for non-small cell lung cancer.

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.

Mechanisms of resistance to chemotherapy in non-small cell lung cancer

Non-small cell lung cancer (NSCLC), which represents 80-85% of lung cancer cases, is one of the leading causes of human death worldwide. The majority of patients undergo an intensive and invasive treatment regimen, which may include radiotherapy, chemotherapy, targeted therapy, immunotherapy, or a combination of these, depending on disease stage and performance status. Despite advances in therapeutic regimens, the 5-year survival of NSCLC is approximately 20-30%, largely due to diagnosis at advanced stages. Conventional chemotherapy is still the standard treatment option for patients with NSCLC, especially those with advanced disease. However, the emergence of resistance to chemotherapeutic agents (chemoresistance) poses a significant obstacle to the management of patients with NSCLC. Therefore, to develop efficacious chemotherapeutic approaches for NSCLC, it is necessary to understand the mechanisms underlying chemoresistance. Several mechanisms are known to mediate chemoresistance. These include altered cellular targets for chemotherapy, decreased cellular drug concentrations, blockade of chemotherapy-induced cell cycle arrest and apoptosis, acquisition of epithelial-mesenchymal transition and cancer stem cell-like phenotypes, deregulated expression of microRNAs, epigenetic modulation, and the interaction with tumor microenvironments. In this review, we summarize the mechanisms underlying chemoresistance and tumor recurrence in NSCLC and discuss potential strategies to avoid or overcome chemoresistance.

Specific c-Jun N-Terminal Kinase Inhibitor, JNK-IN-8 Suppresses Mesenchymal Profile of PTX-Resistant MCF-7 Cells through Modulating PI3K/Akt, MAPK and Wnt Signaling Pathways

Paclitaxel (PTX) is a widely used chemotherapeutic agent in the treatment of breast cancer, and resistance to PTX is a common failure of breast cancer therapy. Therefore, understanding the effective molecular targets in PTX-resistance gains importance in identifying novel strategies in successful breast cancer therapy approaches. The aim of the study was to investigate the functional role of PTX resistance on MCF-7 cell survival and proliferation related to PI3K/Akt and MAPK pathways. The generated PTX-resistant (PTX-res) MCF-7 cells showed enhanced cell survival, proliferation, and colony formation potential with decreased cell death compared to wt MCF-7 cells. PTX-res MCF-7 cells exhibited increased motility profile with EMT, PI3K/Akt, and MAPK pathway induction. According to the significant SAPK/JNK activation in PTX-res MCF-7 cells, specific c-Jun N-terminal kinase inhibitor, JNK-IN-8 is shown to suppress the migration potential of cells. Treatment of JNK inhibitor suppressed the p38 and SAPK/JNK and Vimentin expression. However, the JNK inhibitor further downregulated Wnt signaling members in PTX-res MCF-7 cells. Therefore, the JNK inhibitor JNK-IN-8 might be used as a potential therapy model to reverse PTX-resistance related to Wnt signaling.

MicroRNA-92a Targets SERTAD3 and Regulates the Growth, Invasion, and Migration of Prostate Cancer Cells via the P53 Pathway

Background

The miR-17-92 cluster, consisting of six mature miRNAs including miR-17, miR-18a, miR-19a, miR-19b, miR-20a, and miR-92a, plays a key role in the tumorigenesis and development of various cancers. The dysregulation of the cluster correlates with the biological mechanism of tumor growth and metastasis in vivo. However, the relationship between miR-17-92 cluster and malignancy of prostate cancer remains unclear, and its regulatory mechanism is worth investigating for controlling the proliferation and invasion of prostate cancer.

Materials and Methods

The expressions of miR-17-92 cluster members were measured using real-time quantitative RT-PCR. WB and real-time quantitative RT-PCR were used to detect the expression of SERTAD3, p38, p21, p53 protein levels and transcription levels. Cell proliferation and apoptosis were evaluated using cell proliferation assay, EdU and Hoechst assay, colony formation experiment and flow cytometry analyses. Cell migration and invasion were determined via transwell assays. The TargetScan, miRDB, starBase databases and luciferase reporter assays were used to confirm the target gene of miR-92a.

Results

The relative expression of miR-92a was threefold higher in the metastatic PC-3 cells compared with the non-metastatic LNCaP cells. Down-regulation of miR-92a in PC-3 cells led to the inhibition of cell proliferation, migration, and invasion, while its overexpression in LNCaP cells resulted in the promotion of cell proliferation, migration, and invasion. The role of SERTAD3 in prostate cancer can be alleviated by miR-92a inhibitor.

Conclusion

SERTAD3 was the direct target gene of miR-92a in prostate cancer cells; inhibition of SERTAD3-dependent miR-92a alleviated the growth, invasion, and migration of prostate cancer cells by regulating the expression of the key genes of the p53 pathway, including p38, p53 and p21. These results suggested that targeting SERTAD3 by the induction of overexpression of miR-92a may be a treatment option in prostate cancer.

Targeting MAPK Signaling in Cancer: Mechanisms of Drug Resistance and Sensitivity

Mitogen-activated protein kinase (MAPK) pathways represent ubiquitous signal transduction pathways that regulate all aspects of life and are frequently altered in disease. Here, we focus on the role of MAPK pathways in modulating drug sensitivity and resistance in cancer. We briefly discuss new findings in the extracellular signaling-regulated kinase (ERK) pathway, but mainly focus on the mechanisms how stress activated MAPK pathways, such as p38 MAPK and the Jun N-terminal kinases (JNK), impact the response of cancer cells to chemotherapies and targeted therapies. In this context, we also discuss the role of metabolic and epigenetic aberrations and new therapeutic opportunities arising from these changes.

Unraveling the action mechanism of polygonum cuspidatum by a network pharmacology approach

As a popular Chinese herbal medicine (CHM), polygonum cuspidatum is widely used to treat various diseases in China. However, its biological function and action mechanism have yet to be systematically explored. In the present study, we first identified 14 potential active ingredients of polygonum cuspidatum using the TCMSP server and then conducted an in silico target prediction for these ingredients using PharmMapper. The subsequent KEGG pathway enrichment analysis of the 57 identified potential targets revealed that they were closely associated with cancer and gynecological disorders. Furthermore, a protein-protein interaction network of these targets was constructed using STRING and Cytoscape, through which 11 core targets were excavated according to degree, a key topological parameter. Meanwhile, we developed a novel formula, in which the "R value" is determined by average shortest path length and closeness centrality, two other key topological parameters, to evaluate the reliability of these predicted core targets. Intriguingly, among the top 10 core targets excavated using this new formula, 7 overlapped with the former 11 core targets, showing a good consistency in these core targets between the different prediction algorithms. Next, 7 ingredients were identified/validated from the crude extract of polygonum cuspidatum using UPLC-MS/MS. Noteworthy, 6 potential targets predicted for these 7 ingredients overlapped with the 7 core targets excavated from the previous in silico analyses. Further molecular docking and druggability analyses suggested that polydatin may play a pivotal role in manifesting the therapeutic effects of polygonum cuspidatum. Finally, we carried out a series of cell functional assays, which validated the anti-proliferative effects of polygonum cuspidatum on gynecological cancer cells, thus demonstrating our network pharmacology approach is reliable and powerful enough to guide the CHM mechanism study.

P38 Signal Transduction Pathway Has More Cofactors on Apoptosis of SGC-7901 Gastric Cancer Cells Induced by Combination of Rutin and Oxaliplatin

Currently, gastric cancer treatment is mainly based on first-line intervention with oxaliplatin (OXA) after surgical resection, but the application of OXA has been limited due to the toxic side effects caused by the cumulative dose. The toxicity of OXA mainly includes hepatotoxicity, nephrotoxicity, and ototoxicity, and there is an urgent clinical need to find alternatives that are less toxic and more effective. Rutin (RT) is a natural flavonoid with many biological activities. Studies have found that RT inhibits tumor cell growth and enhances their sensitivity toward certain drugs. As the underlying impact of RT on gastric cancer and its molecular mechanism remain poorly understood, we performed a series of experiments to determine whether RT has the effect of treating gastric cancer, and whether it can cooperate with OXA to treat gastric cancer and its related mechanisms. In the present study, we founded that RT suppressed cell viability, inhibited cell proliferation by causing G0/G1 arrest, and induced apoptosis in SGC 7901 cells. And RT can play as an antitumor agent together with OXA. The mechanism of RT-induced apoptosis may be associated with the activation of the p38/Caspase signal pathway. These results demonstrated the potential of RT as a promising therapeutic compound to treat gastric cancer. At the same time, RT can synergize with OXA to reduce the dose of OXA and reduce the toxicity.

A Novel Tanshinone Analog Exerts Anti-Cancer Effects in Prostate Cancer by Inducing Cell Apoptosis, Arresting Cell Cycle at G2 Phase and Blocking Metastatic Ability

Prostate cancer (PCa), an epithelial malignant tumor, is the second common cause of cancer death among males in western countries. Thus, the development of new strategies is urgently needed. Tanshinones isolated from Salvia miltiorrhiza and its synthetic analogs show various biological activities including anticancer effects. Among them, the tanshinone analog 2-((Glycine methyl ester)methyl)-naphtho (TC7) is the most effective, with better selectivity and lower toxicity. Therefore, in this work, the effect of TC7 against PCa was investigated through assessing the molecular mechanisms regulating the growth, metastasis, and invasion of PCa cells. Human PCa cells, PC3 and LNCAP, were used to evaluate TC7 mechanisms of action in vitro, while male BALB/c nude mice were used for in vivo experiments by subjecting each mouse to a subcutaneous injection of PC3 cells into the right flank to evaluate TC7 effects on tumor volume. Our in vitro results showed that TC7 inhibited cell proliferation by arresting the cell cycle at G2/M through the regulation of cyclin b1, p53, GADD45A, PLK1, and CDC2/cyclin b1. In addition, TC7 induced cell apoptosis by regulating apoptosis-associated genes such as p53, ERK1, BAX, p38, BCL-2, caspase-8, cleaved-caspase-8, PARP1, and the phosphorylation level of ERK1 and p38. Furthermore, it decreased DNA synthesis and inhibited the migration and invasion ability by regulating VEGF-1 and MMP-9 protein expression. Our in vivo evidence supports the conclusion that TC7 could be considered as a potential promising chemotherapeutic candidate in the treatment of PCa.

MAP3K1 rs889312 genotypes influence survival outcomes of Chinese gastric cancer patients who received adjuvant chemotherapy based on platinum and fluorouracil regimes

Background

For patients with gastric cancer (GC), adjuvant chemotherapy is a standard therapy. However, the responses to the treatment are quite different. Mitogen-activated protein kinase (MAPK) pathway is a core pathway that modulates the efficacy of anticancer drugs. The purpose of our study was to investigate the clinical significance of one pivotal functional gene polymorphism in the MAPK pathway – MAP3K1 rs889312 – in patients with stage II GC to stage III GC.

Methods

The genotypes of MAP3K1 rs889312 were analyzed in 591 GC patients enrolled in this study who had received radical gastrectomy. Among them, 204 patients accepted adjuvant chemotherapy based on platinum and fluorouracil (PF) regimens after an operation. Cox regression analysis, log-rank test and Kaplan–Meier method were used to explore the link between MAP3K1 rs889312 variant and overall survival (OS) of GC.

Results

Compared with the AA genotype (mean OS of 68.12 months), MAP3K1 rs889312 AC/CC significantly reduced the mean OS of 56.83 months in patients who received adjuvant chemotherapy only. In addition, AC/CC genotype had a negative impact on OS of patients who received oxaliplatin-based therapy (HR, 8.253; 95% CI: 1.119–60.853, log-rank p=0.013). Stratification analysis showed that MAP3K1 rs889312 AC/CC significantly reduced OS of patients with tumors smaller than or equal to 5 cm in size (HR, 3.706; 95% CI: 1.329–10.335, p=0.012), poorly differentiated tumors (HR, 3.002; 95% CI: 1.076–8.377, p=0.036) and intestinal tumors (HR, 4.780; 95% CI: 1.138–20.073, p=0.033).

Conclusion

Our findings suggested that MAP3K1 rs889312 single-nucleotide polymorphism may be considered as a biomarker for adjuvant chemotherapy reaction and can predict prognosis of GC patients who received PF-based therapy.

Synergistic Effect of Novel EGFR Inhibitor AZD8931 and p38α siRNA in Lung Adenocarcinoma Cancer Cells

Background:

Lung cancer is the leading cause of cancer-related death with less than 5-year survival rate for both men and women worldwide. EGFR and MAPK signaling pathways have a critical role in proliferation and progression of various cancers, including lung cancer. P38 map kinase plays different role in various tissue hence showing a tissue-dependent behavior. It acts as an oncogene in some tissues while plays as tumor suppressor in some other tissues. The aim of this study was to investigate the combined effect of P38 αspecific siRNA and EGFR inhibitor on apoptosis and proliferation of A549 lung cancer cell line.

Objective:

This article is dedicated to the synergistic effect of novel EGFR inhibitor AZD8931 and P38 α siRNA in lung adenocarcinoma cancer cells proliferation and apoptosis.

Methods and Materials:

The A549 lung cancer cells were treated with P38 α- siRNA and EGFR inhibitor alone or in combination. The cytotoxic effects of P38 α- siRNA and EGFR inhibitor were determined using MTT assay. Relative P38 α and EGFR mRNA levels were measured by QRT-PCR. Induction of apoptosis were measured by FACS analysis.

Results:

The expression of mRNA related to P38 α, EGFR, and Her2 genes was reduced to 23.4%, 52.4%, and 75, respectively, after treatment of their inhibitors. Also, MTT assay showed that the cell viability after treatment with p38 α SiRNA, EGFR inhibitor and their combination was reduced to 51.02%, 48.9%, and 25.11%, respectively. FACS results indicated that p38 α siRNA, EGFR inhibitor and their combination, reduced the population of live cells to 49.5%, 32.2% and 14.3% in comparison to the population of untreated control cells (99.5%).

Conclusion:

The results of this study indicated that p38 α and EGFR might play an important role in the development and growth of lung cancer and might be a potential therapeutic target for the treatment of lung cancer.

Plastin 3 down-regulation augments the sensitivity of MDA-MB-231 cells to paclitaxel via the p38 MAPK signalling pathway

Plastin 3 (PLS3) overexpression may serve as a marker for predicting chemotherapeutic outcomes in drug-resistant cancer cells, but the mechanism is unclear. Herein, we show that the down-regulation of PLS3 by PLS3 gene silencing augments the sensitivity of MDA-MB-231 triple-negative breast cancer cells to paclitaxel. Interestingly, a low concentration of paclitaxel was able to induce strong apoptosis in the PLS3-silenced cells. Further study revealed that p38 MAPK signalling was responsible for the increased sensitivity to paclitaxel in these cells, as the p38 MAPK inhibitor SB203580 impaired the changes mediated by PLS3 down-regulation in response to paclitaxel. Therefore, our study identifies PLS3 as a potential target for enhancing the p38 MAPK-mediated apoptosis induced by paclitaxel. Unlike paclitaxel, Abraxane was unable to induce strong apoptosis in the PLS3-silenced cells. As PLS3 was found to be involved in the process of endocytosis in breast cancer cells, the reliance of cellular Abraxane uptake on this process may render it not as efficient as paclitaxel in PLS3-depleted tumour cells. The finding that PLS3 could be a critical regulator of paclitaxel sensitivity may have important implications for breast cancer chemotherapy.

Stability of blueberry anthocyanin, anthocyanidin and pyranoanthocyanidin pigments and their inhibitory effects and mechanisms in human cervical cancer HeLa cells

Anthocyan-rich foods have attracted lots of attention because of their potential biological and pharmacological applications. Anthocyanins richly exist in blueberry fruits and have been proved to possess various bioactive properties. Despite the potential application of anthocyanins in the food, pharmaceutical and cosmetic industries, their use is limited because of their relative instability. Recently, much attention has been given to a particular family of anthocyanin derivatives, the pyranoanthocyanins that have been indicated to have higher stability than the original anthocyanins. However, the anti-cancer activity of pyranoanthocyanins is largely unknown. The objective of this study was to conduct a comparative analysis on the stability and anti-cancer activities of anthocyanins, anthocyanidins and pyranoanthocyanidins. Pyranoanthocyanidins exhibited the highest stability in the pH range 3.0-9.0, while anthocyanidins had the strongest inhibition on HeLa cells among the three anthocyan pigments. All the anthocyan pigments could effectively induce cell cycle arrest at the G2/M phase in conjunction with a marked increase in the expression of the p53 protein. Exposure of HeLa cells to three anthocyan pigments caused pronounced late apoptosis that might be involved in the activation of the p38 MAPK/p53 signaling pathway. These findings suggest that anthocyanidins and pyranoanthocyanidins might be more promising anti-cancer agents than anthocyanins and warrant further evaluation regarding the molecular mechanisms.

Astragalus Polysaccharide RAP Selectively Attenuates Paclitaxel-Induced Cytotoxicity Toward RAW 264.7 Cells by Reversing Cell Cycle Arrest and Apoptosis

Purpose: The purpose of this study was to determine if an Astragalus polysaccharide (RAP) can protect immune cells from the toxic side effects of paclitaxel (Taxol), a powerful anti-tumor drug whose equally powerful side effects limit its clinical use. Methods: We hypothesized that RAP can reduce the toxic effects induced by Taxol. To test this hypothesis, we conducted a series of studies in vivo and in vitro. First, we confirmed RAP's effects in vivo utilizing BALB/c mice inoculated with 4T1 mouse breast cancer cells as the tumor model. Mice were treated with RAP and/or Taxol, and the differences in the life spans were recorded. Second, a co-culture cell model was used to study the protective effect of RAP on cells vis-a-vis Taxol. The cell cycle and apoptosis of RAW 264.7 cells that were treated with RAP with/without Taxol were checked by flow cytometry and Hoechst staining. Proteins involved in the cell cycle and apoptosis were also tested by Western blot to reveal the probable mechanism. Results: RAP prolonged the life span of tumor-bearing mice treated with Taxol. The in vitro experiments showed that Taxol suppressed the proliferation of RAW 264.7 cells while RAP protected the RAW 264.7 cells from Taxol-induced suppression. The protection is selective because RAP had no effect on 4T1 cells. Furthermore, Taxol clearly led to cell cycle arrest mainly at the G2/M phase and generated cytotoxicity against RAW 264.7 cells, while RAP blocked cell cycle arrest and protected cells from apoptosis. Taxol up-regulated the protein levels of P-H2A, PARP, Chk1, p53, and p21 and down-regulated Bcl-Xl and Mcl-1, and RAP reversed the expression of all these proteins. Conclusion: These results suggested that RAP can protect immune cells from Taxol-induced toxicity, by changing the cell cycle and apoptosis.

Targeting the KRAS, p38α, and NF-κB in lung adenocarcinoma cancer cells: The effect of combining RNA interferences with a chemical inhibitor

BACKGROUND

Lung cancer is the leading cause of cancer-related death with less than 5-year survival rate for both men and women worldwide. KRAS (Kirsten rat sarcoma), nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways have a critical role in the proliferation and progression of various cancers, including lung cancer. The p38 MAPK plays a different role in various tissue hence show a tissue-dependent behavior. It acts as an oncogene in some tissues while plays as a tumor suppressor in some other tissues. Also, KRAS and NF-κB act as an oncogene in various cancer. This study was dedicated to analyzing the combined effect of NF-κB inhibitor, specific KRAS, and p38α small interfering RNA (siRNA) in A549 cell line.

MATERIALS AND METHODS

The cytotoxic effects of p38α siRNA, KRAS siRNA, and NF-κB inhibitor were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) assay. Relative p38α, KRAS, and NF-κB messenger RNA (mRNA) levels were measured by quantitative reverse-transcription polymerase chain reaction. Induction of apoptosis by treatments was measured by fluorescence-activated cell sorting (FACS) analysis.

RESULTS

The expression of mRNA related to p38α and KRAS genes was reduced to 23.4% and 26.7%, respectively, after treatment with specific siRNAs. Also, MTT assay showed that the cell viability after treatment with p38α siRNA, KRAS siRNA, NF-κB inhibitor and their combination was reduced. FACS results indicated that p38α siRNA, KRAS siRNA, and NF-κB inhibitor, and their combination, reduced the population of live cells in comparison with the population of untreated control cells (99.5%). The results are expressed as mean ± SD (n = 3); *P < 0.05; ** P < 0.01; *** P < 0.001; **** P < 0.0001 vs control group.

CONCLUSION

The results of this study indicated that p38α, KRAS, and NF-κB signaling pathways might play an important role in the development and growth of lung cancer and might be a potential therapeutic target for treatment of lung cancer.

Interaction with AEG-1 and MDM2 is associated with glioma development and progression and correlates with poor prognosis

Glioma is the most common central nervous system tumor with poor prognosis. The AEG-1 (Astrocyte Elevated Gene 1) gene displays oncogenic characteristics, including proliferation, metastasis, chemoresistance, invasion, and evasion of apoptosis, and is strongly linked to the occurrence of glioma. Here, we elucidated the potential contribution of AEG-1 in human glioma pathogenesis. In glioma cells, AEG-1 could directly interact with Murine Double Minute-2 (MDM2) protein resulting in MDM2-p53-mediated cell proliferation and apoptosis. MDM2 is being revealed as an oncoprotein, which is involved in many human cancers progression. By immunohistochemical and a multivariate analysis, expressions of AEG-1 and MDM2 were elevated in glioma and high AEG-1 and MDM2 expressions were showed to be correlated with poor prognosis. AEG-1-MDM2 interaction prolonged stabilization of MDM2 where AEG-1 inhibited ubiquitination and subsequent proteasome-mediated degradation of MDM2 protein. Moreover, slicing AEG-1 blocked MDM2 expression and then impacted MDM2-p53 pathway that influenced cell proliferation and apoptosis. These findings uncover a novel AEG-1-MDM2 interplay by which AEG-1 augments glioma progression and reveal a viable potential therapy for the treatment of glioma patients.

Alteration of microRNA profiling in sphere-cultured ovarian carcinoma cells

Ovarian cancer is an aggressive and lethal cancer, which in part, can be attributed to complications in the effective detection of this disease during early stages of progression. Frequently, epithelial ovarian cancer is disseminated to the abdominal cavity and forms multicellular aggregates. This unique early metastatic event, and formation of the multicellular aggregate is implicated to provide a basis for understanding the underlying molecular mechanisms of metastasis in ovarian cancer. Therefore, a 3-dimensional (3D) sphere culture system was established in the present study to mimic the later stages of ovarian cancer. The aim of the present study was to investigate whether microRNAs (miRNAs), which have functions in metastasis and chemoresistance in various cancer models, are altered in ovarian cancer cells by 3-dimensional (3D) culture. A multicellular aggregate of SKOV3ip1 ovarian carcinoma cells was generated using a 3D sphere culture system. Cell viability analysis demonstrated that the sphere-cultured SKOV3ip1 cells exhibited chemoresistance compared with those in a conventional 2-dimensional (2D) monolayer cultured SKOV3ip1 system. Under the same experimental conditions, 71 upregulated miRNAs and 63 downregulated miRNAs were identified in the 3D sphere-cultured SKOV3ip1 cells. The predicted targets of the 3D sphere-culture specific miRNAs were further identified using PITA, microRNAorg and TargetScan. Compared with the target gene pool and Kyoto Encyclopedia of Genes and Genomes pathway, the present study provides evidence that the 3D sphere culture-specific miRNAs regulated sphere formation and chemoresistance in 3D sphere-cultured SKOV3ip1 cells. Overall, the results of the present study demonstrated that miRNA-mediated regulation is implicated to provoke features of SKOV3ip1 multicellular aggregation, including sphere formation and chemoresistance.

FGFR3, as a receptor tyrosine kinase, is associated with differentiated biological functions and improved survival of glioma patients

Background

Activation of receptor tyrosine kinases is common in Malignancies. FGFR3 fusion with TACC3 has been reported to have transforming effects in primary glioblastoma and display oncogenic activity in vitro and in vivo. We set out to investigate the role of FGFR3 in glioma through transcriptomic analysis.

Results

FGFR3 increased in Classical subtype and Neural subtype consistently in CGGA and TCGA cohort. Similar patterns of FGFR3 distribution through subtypes were observed in CGGA and TCGA samples. Gene ontology analysis was performed with genes that were significantly correlated with FGFR3 expression. We found that positively associated biological processes of FGFR3 were focused on differentiated cellular functions and neuronal activities, while negatively correlated biological processes focused on mitosis and cell cycle phase. Clinical investigation showed that higher FGFR3 expression predicted improved survival for glioma patients, especially in Proneural subtype. Moreover, FGFR3 showed very limited relevance with other receptor tyrosine kinases in glioma at transcriptome level.

Materials and Methods

FGFR3 expression data of glioma was obtained from Chinese Glioma Genome Atlas (CGGA) and TCGA (The Cancer Genome Atlas). In total, RNA sequencing data of 325 glioma samples and mRNA microarray data of 301 samples from CGGA dataset were enrolled into this study. To consolidate the findings that we have revealed in CGGA dataset, RNA-seq data of 672 glioma samples from TCGA dataset were used as a validation cohort. R language was used as the main tool to perform statistical analysis and graphical work.

Conclusions

FGFR3 expression increased in classical and neural subtypes and was associated with differentiated cellular functions. FGFR3 showed very limited correlation with other common receptor tyrosine kinases, and predicted improved survival for glioma patients.

Systems Biology Analysis to Understand Regulatory miRNA Networks in Lung Cancer

Lung cancer has currently the highest cancer-related mortality rate worldwide. MicroRNAs (miRNAs) are small noncoding RNAs that play a fundamental role in gene expression and are linked to disease progression of different cancer types such as lung cancer. However, functional characterization is made difficult by the fact that miRNAs generally regulate several mRNA interaction partners, resulting in complex regulatory networks. Thus, analysis of the network biology of miRNAs is essential for comprehensive understanding of their regulatory effects in lung cancer. A deeper understanding of miRNA networks in cancer could finally serve as a basis for the development of new therapeutic interventions. Here, we present a systems biology approach to analyze regulatory miRNA interaction networks to get better insight into their function.

Panaxynol, a natural Hsp90 inhibitor, effectively targets both lung cancer stem and non-stem cells

Cancer stem-like cells (CSCs) contribute to tumor recurrence and chemoresistance. Hence, strategies targeting CSCs are crucial for effective anticancer therapies. Here, we demonstrate the capacities of the non-saponin fraction of Panax ginseng and its active principle panaxynol to inhibit Hsp90 function and viability of both non-CSC and CSC populations of NSCLC in vitro and in vivo. Panaxynol inhibited the sphere forming ability of NSCLC CSCs at nanomolar concentrations, and micromolar concentrations of panaxynol suppressed the viability of NSCLC cells (non-CSCs) and their sublines carrying acquired chemoresistance with minimal effect on normal cells derived from various organs. Orally administered panaxynol significantly reduced lung tumorigenesis in Kras^G12D/+ transgenic mice and mice carrying NSCLC xenografts without detectable toxicity. Mechanistically, panaxynol disrupted Hsp90 function by binding to the N-terminal and C-terminal ATP-binding pockets of Hsp90 without increasing Hsp70 expression. These data suggest the potential of panaxynol as a natural Hsp90 inhibitor targeting both the N-terminal and C-terminal of Hsp90 with limited toxicities.

Glioma targeting peptide in combination with the P53 C terminus inhibits glioma cell proliferation in vitro

Glioma is a prevalent malignant primary brain tumor in adults, the treatment for which remains a challenge due to its high infiltration and recurrence. Hence, treatments that lead to the suppression of glioma cell migration and invasion may be used in addition to surgery to increase the therapeutic outcome. In this study, we aimed to construct a multifunctional protein that would exert an effect on glioma cell proliferation and migration. The protein is named GL1-P53C-11R and it consists of the glioma-targeting peptide GL1 (G), the P53 C terminus (Pc) and the cell-penetrating peptide arginine (R). GL1-P53C-R was expressed with the fusion protein ZZ and immunofluorescence analysis showed effective delivery of the fused ZZ-GL1-P53C-R protein represented as ZZ-GPcR. The ZZ-GPcR exhibited an inhibitory effect on the proliferation, migration and invasion of U87ΔEGFR cells. Western blotting results indicated that it caused significant changes in the expression levels of cell cycle and apoptotic proteins. Flow cytometric analysis showed increase apoptosis. Our findings suggest that the P53C in the fusion protein ZZ-GPcR can enter into glioma cells to exert its inhibitory effect.

TMPYP4 exerted antitumor effects in human cervical cancer cells through activation of p38 mitogen-activated protein kinase

Background

The aim of the present study was to investigate the potential effects of the 5,10,15,20-tetrakis (1-methylpyridinium-4-yl) porphyrin (TMPyP4) on the proliferation and apoptosis of human cervical cancer cells and the underlying mechanisms by which TMPyP4 exerted its actions.

Results

After human cervical cancer cells were treated with different doses of TMPyP4, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method, the apoptosis was observed by flow cytometry (FCM), and the expression of p38 mitogen-activated protein kinase (MAPK), phosphated p38 MAPK (p-p38 MAPK), capase-3, MAPKAPK2 (MK-2) and poly ADP-ribose polymerase (PARP) was measured by Western blot analysis. The analysis revealed that TMPyP4 potently suppressed cell viability and induced the apoptosis of human cervical cancer cells in a dose-dependent manner. In addition, the up-regulation of p-p38 MAPK expression levels was detected in TMPyP4-treated human cervical cancer cells. However, followed by the block of p38 MAPK signaling pathway using the inhibitor SB203580, the effects of TMPyP4 on proliferation and apoptosis of human cervical cancer cells were significantly changed.

Conclusions

It was indicated that TMPyP4-inhibited proliferation and -induced apoptosis in human cervical cancer cells was accompanied by activating the p38 MAPK signaling pathway. Taken together, our study demonstrates that TMPyP4 may represent a potential therapeutic method for the treatment of cervical carcinoma.

Curcumin increases the sensitivity of Paclitaxel-resistant NSCLC cells to Paclitaxel through microRNA-30c-mediated MTA1 reduction

Non-small-cell lung cancer is one of the most lethal cancers in the worldwide. Although Paclitaxel-based combinational therapies have long been used as a standard treatment in aggressive non-small-cell lung cancers, Paclitaxel resistance emerges as a major clinical problem. It has been demonstrated that Curcumin from Curcuma longa as a traditional Chinese medicine can inhibit cancer cell proliferation. However, the role of Curcumin in Paclitaxel-resistant non-small-cell lung cancer cells is not clear. In this study, we investigated the effect of Curcumin on the Paclitaxel-resistant non-small-cell lung cancer cells and found that Curcumin treatment markedly increased the sensitivity of Paclitaxel-resistant non-small-cell lung cancer cells to Paclitaxel. Mechanically, the study revealed that Curcumin could reduce the expression of metastasis-associated gene 1 (MTA1) gene through upregulation of microRNA-30c in Paclitaxel-resistant non-small-cell lung cancer cells. During the course, MTA1 reduction sensitized Paclitaxel-resistant non-small-cell lung cancer cells and enhanced the effect of Paclitaxel. Taken together, our studies indicate that Curcumin increases the sensitivity of Paclitaxel-resistant non-small-cell lung cancer cells to Paclitaxel through microRNA-30c-mediated MTA1 reduction. Curcumin might be a potential adjuvant for non-small-cell lung cancer patients during Paclitaxel treatment.

Molecular mechanism underlying the pharmacological interactions of the protein kinase C-β inhibitor enzastaurin and erlotinib in non-small cell lung cancer cells

Erlotinib is commonly used as a second line treatment in non-small cell lung cancer patients with sensitizing EGFR mutations. In EGFR-wild type patients, however the results are limited. Therefore we evaluated whether the combination of the Protein kinase C-β inhibitor enzastaurin with erlotinib could enhance the effect in the A549 and H1650 cell lines. Cytotoxicity of erlotinib, enzastaurin and their 72-h simultaneous combination was assessed with the MTT assay. The pharmacologic interaction was studied using the method of Chou and Talalay, cell cycle perturbations were assessed by flow cytometry and modulation of ERK1/2 and AKT phosphorylation was determined with ELISA. For protein phosphorylation of GSK3β we performed Western Blot analysis and a Pamgene phosphorylation array, while RT-PCR was used to investigate VEGF and VEGFR-2 expression before and after drug treatments. A synergistic interaction was found in both cell lines with mean CI of 0.58 and 0.63 in A549 and H1650 cells, respectively. Enzastaurin alone and in combination with erlotinib increased the percentage of cells in S and G2M phase, mostly in H1650 cells, while AKT, ERK1/2 and GSK3β phosphorylation were reduced in both cell lines. VEGF expression decreased 5.0 and 6.9 fold in A549 cells after enzastaurin alone and with erlotinib, respectively, while in H1650 only enzastaurin caused a relevant reduction in VEGF expression. The array showed differential phosphorylation of EGFR, GSK3β, EphA1 and MK14. In conclusion, enzastaurin is a protein kinase Cβ inhibitor, working on several cellular signaling pathways that are involved in proliferation, apoptosis and angiogenesis. These features make it a good compound for combination therapy. In the present study the combination of enzastaurin and erlotinib gives synergistic results, warranting further investigation.

Tyrosine Kinase Receptor Landscape in Lung Cancer: Therapeutical Implications

Lung cancer is a heterogeneous disease responsible for the most cases of cancer-related deaths. The majority of patients are clinically diagnosed at advanced stages, with a poor survival rate. For this reason, the identification of oncodrivers and novel biomarkers is decisive for the future clinical management of this pathology. The rise of high throughput technologies popularly referred to as “omics” has accelerated the discovery of new biomarkers and drivers for this pathology. Within them, tyrosine kinase receptors (TKRs) have proven to be of importance as diagnostic, prognostic, and predictive tools and, due to their molecular nature, as therapeutic targets. Along this review, the role of TKRs in the different lung cancer histologies, research on improvement of anti-TKR therapy, and the current approaches to manage anti-TKR resistance will be discussed.