Regulation of AKT phosphorylation by GSK3β and PTEN to control chemoresistance in breast cancer

A New Strategy for Adult T-Cell Leukemia Treatment Targeting Glycogen Synthase Kinase-3β

OBJECTIVES

The role of glycogen synthase kinase (GSK)-3β in adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type 1 (HTLV-1) is paradoxical and enigmatic. Here, we investigated the role of GSK-3β and its potential as a therapeutic target for ATL.

METHODS

Cell proliferation/survival, cell cycle, apoptosis, and reactive oxygen species (ROS) generation were examined using the WST-8 assay, flow cytometry, and Hoechst 33342 staining, respectively. Expression of GSK-3β and cell cycle/death-related proteins, and survival signals was analyzed using RT-PCR, immunofluorescence staining, and immunoblotting.

RESULTS

HTLV-1-infected T-cell lines showed nuclear accumulation of GSK-3β. GSK-3β knockdown and its inhibition with 9-ING-41 and LY2090314 suppressed cell proliferation/survival. 9-ING-41 induced G2/M arrest by enhancing the expression of γH2AX, p53, p21, and p27, and suppressing the expression of CDK1, cyclin A/B, and c-Myc. It induced caspase-mediated apoptosis by decreasing the expression of Bcl-xL, Mcl-1, XIAP, c-IAP1/2, and survivin, and increasing the expression of Bak and Bax. 9-ING-41 also induced ferroptosis and necroptosis, promoted JNK phosphorylation, and suppressed IKKγ and JunB expression. It inhibited the phosphorylation of IκBα, Akt, and STAT3/5, induced ROS production, and reduced glycolysis-derived lactate levels.

CONCLUSION

GSK-3β functions as an oncogene in ATL and could be a potential therapeutic target.

Pharmacological and biochemical insights into lead-induced hepatotoxicity: Pathway interplay and the protective effects of arbutin via the oral and intraperitoneal routes in silico and in vivo

INTRODUCTION

Lead acetate (PbAc), a hazardous heavy metal, poses significant threats to human health and the environment because of widespread industrial exposure. PbAc exposure leads to liver injury primarily through oxidative stress and the disruption of key regulatory pathways. Understanding these mechanisms and exploring protective agents are vital for mitigating PbAc-induced hepatotoxicity. Therefore, we aimed to investigate the molecular pathways implicated in PbAc-induced liver damage, focusing on Sirt-1, Nrf2 (HO-1, NQO1, and SOD), Akt-1/GSK3β, m-TOR, and P53. Additionally, we aimed to assess the hepatoprotective effects of arbutin, which is administered orally and intraperitoneally, to determine the most effective delivery method.

METHODOLOGY

In silico analyses were conducted to identify relevant protein networks associated with Sirt-1 and AKT-1/GSK-3B pathways. The pharmacodynamic properties of arbutin were examined, followed by molecular docking studies to elucidate its interactions with the selected protein network. In vivo preclinical studies were carried out on adult male rats randomly assigned to 6 different treatment groups, including PbAc exposure and PbAc exposure treated with arbutin either orally or intraperitoneally.

RESULTS

PbAc exposure led to hepatic oxidative stress, as evidenced by elevated MDA levels and SIRT-1 inhibition, disrupting antioxidant pathways and activating antiautophagic and proapoptotic pathways, ultimately resulting in hepatocyte necrosis. Both oral and intraperitoneal arbutin administration effectively modifed these effects, with intraperitoneal delivery showing superior efficacy in mitigating PbAc-induced histological, immunological, and biochemical alterations.

CONCLUSION

This study provides insights into the molecular mechanisms underlying PbAc-induced liver injury and highlights the hepatoprotective potential of arbutin. These findings suggest that arbutin, particularly when administered intraperitoneally, holds promise as a therapeutic agent for combating PbAc-induced hepatotoxicity.

PFKFB3 facilitates cell proliferation and migration in anaplastic thyroid carcinoma via the WNT/β-catenin signaling pathway

PURPOSE

Despite the involvement of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase3 (PFKFB3) in the proliferation and metastasis of diverse tumor types, its biological functions and related molecular mechanisms in anaplastic thyroid carcinoma (ATC) remain largely unclear.

METHODS

Datasets from the Gene Expression Omnibus, the Cancer Genome Atlas and immunohistochemistry (IHC) analyses were employed to measure the expression level of PFKFB3 in ATC. A series of assays were performed to analyze the role of PFKFB3 and its inhibitor KAN0438757 in ATC cell proliferation and migration. Furthermore, Western blotting (WB), IHC and luciferase reporter assay were conducted to investigate the potential mechanisms underlying the involvement of PFKFB3 and KAN0438757 in ATC. Additionally, we established a subcutaneous xenograft tumor model in nude mice to evaluate the in vivo tumor growth.

RESULTS

PFKFB3 exhibited a significant increase in its expression level in ATC tissues. The overexpression of PFKFB3 resulted in the stimulation of ATC cell proliferation and migration. Furthermore, this overexpression was associated with the elevated expression levels of p-AKT (ser473), p-GSK3α/β (ser21/9), nuclear β-catenin, fibronectin1 (FN1), matrix metallopeptidase 9 (MMP-9) and cyclin D1. It also promoted the nuclear translocation of β-catenin and the transcription of downstream molecules. Conversely, contrasting results were observed with the downregulation or KAN0438757-mediated inhibition of PFKFB3 in ATC cells. The selective AKT inhibitor MK2206 was noted to reverse the increased expression of p-AKT (ser473) and p-GSK3α/β (ser21/9) induced by PFKFB3 overexpression. The level of lactate was increased in PFKFB3-overexpressing ATC cells, while the presence of KAN0438757 inhibited lactate production. Moreover, the simultaneous use of PFKFB3 downregulation and KAN0438757 was found to suppress subcutaneous tumor growth in vivo.

CONCLUSION

PFKFB3 can enhance ATC cell proliferation and migration via the WNT/β-catenin signaling pathway and plays a crucial role in the regulation of aerobic glycolysis in ATC cells.

GSK3β: A ray of hope for the treatment of diabetic kidney disease

Diabetic kidney disease (DKD), a major microvascular complication of diabetes, is characterized by its complex pathogenesis, high risk of chronic renal failure, and lack of effective diagnosis and treatment methods. GSK3β (glycogen synthase kinase 3β), a highly conserved threonine/serine kinase, was found to activate glycogen synthase. As a key molecule of the glucose metabolism pathway, GSK3β participates in a variety of cellular activities and plays a pivotal role in multiple diseases. However, these effects are not only mediated by affecting glucose metabolism. This review elaborates on the role of GSK3β in DKD and its damage mechanism in different intrinsic renal cells. GSK3β is also a biomarker indicating the progression of DKD. Finally, the protective effects of GSK3β inhibitors on DKD are also discussed.

Molecular Targeting of the Phosphoinositide-3-Protein Kinase (PI3K) Pathway across Various Cancers

The dysregulation of the phosphatidylinositol-3-kinase (PI3K) pathway can lead to uncontrolled cellular growth and tumorigenesis. Targeting PI3K and its downstream substrates has been shown to be effective in preclinical studies and phase III trials with the approval of several PI3K pathway inhibitors by the Food and Drug Administration (FDA) over the past decade. However, the limited clinical efficacy of these inhibitors, intolerable toxicities, and acquired resistances limit the clinical application of PI3K inhibitors. This review discusses the PI3K signaling pathway, alterations in the PI3K pathway causing carcinogenesis, current and novel PI3K pathway inhibitors, adverse effects, resistance mechanisms, challenging issues, and future directions of PI3K pathway inhibitors.

Histone acetylation: a key determinant of acquired cisplatin resistance in cancer

Cisplatin is an alkylating class of chemotherapeutic drugs used to treat cancer patients. However, cisplatin fails in long-term treatment, and drug resistance is the primary reason for tumor recurrence. Hence, understanding the mechanism of acquirement of chemoresistance is essential for developing novel combination therapeutic approaches. In this study, in vitro cisplatin-resistant cancer cell line models were developed. Gene ontology and GSEA of differentially expressed genes between parental and resistant cells suggest that PI3K-AKT signaling, central carbon metabolism, and epigenetic-associated phenomenon alter in cisplatin-resistant cells. Further, the data showed that increased glucose transport, alteration in the activity of histone-modifying enzymes, and acetyl-CoA levels in resistant cells paralleled an increase in global histone acetylation. Enrichment of histone acetylation on effectors of PI3K-AKT and glycolysis pathway provides evidence of epigenetic regulation of the key molecules in drug resistance. Moreover, cisplatin treatment to resistant cells showed no significant changes in histone acetylation marks since drug treatment alters cell epigenome. In continuation, targeting PI3K-AKT signaling and glycolysis leads to alteration in histone acetylation levels and re-sensitization of resistant cells to chemo-drug. The data provide evidence of histone acetylation's importance in regulating pathways and cisplatin-resistant cells' cell survival. Our study paves the way for new approaches for developing personalized therapies in affecting metabolic pathways and epigenetic changes to achieve better outcomes for targeting drug-resistant cells.

Anti-Gene IGF-I Vaccines in Cancer Gene Therapy: A Review of a Case of Glioblastoma

OBJECTIVE

Vaccines for the deadliest brain tumor - glioblastoma (GBM) - are generally based on targeting growth factors or their receptors, often using antibodies. The vaccines described in the review were prepared to suppress the principal cancer growth factor - IGF-I, using anti-gene approaches either of antisense (AS) or of triple helix (TH) type. Our objective was to increase the median survival of patients treated with AS and TH cell vaccines.

METHODOLOGY

The cells were transfected in vitro by both constructed IGF-I AS and IGF-I TH expression episomal vectors; part of these cells was co-cultured with plant phytochemicals, modulating IGF-I expression. Both AS and TH approaches completely suppressed IGF-I expression and induced MHC-1 / B7 immunogenicity related to the IGF-I receptor signal.

RESULTS

This immunogenicity proved to be stronger in IGF-I TH than in IGF-I AS-prepared cell vaccines, especially in TH / phytochemical cells. The AS and TH vaccines generated an important TCD8+ and TCD8+CD11b- immune response in treated GBM patients and increased the median survival of patients up to 17-18 months, particularly using TH vaccines; in some cases, 2- and 3-year survival was reported. These clinical results were compared with those obtained in therapies targeting other growth factors.

CONCLUSION

The anti-gene IGF-I vaccines continue to be applied in current GBM personalized medicine. Technical improvements in the preparation of AS and TH vaccines to increase MHC-1 and B7 immunogenicity have, in parallel, allowed to increase in the median survival of patients.

Progress in investigating the relationship between Schlafen5 genes and malignant tumors

The Schlafen5(SLFN5)gene belongs to the third group of the Schlafen protein family. As a tumor suppressor gene, SLFN5 plays a pivotal role in inhibiting tumor growth, orchestrating cell cycle regulation, and modulating the extent of cancer cell infiltration and metastasis in various malignancies. However, the high expression of SLFN 5 in some tumors was positively correlated with lymph node metastasis, tumor stage, and tumor grade. This article endeavors to elucidate the reciprocal relationship between the SLFN5 gene and malignant tumors, thereby enhancing our comprehension of the intricate mechanisms underlying the SLFN5 gene and its implications for the progression, invasive potential, and metastatic behavior of malignant tumors. At the same time, this paper summarizes the basis of SLFN 5 as a new biomarker of tumor diagnosis and prognosis, and provides new ideas for the target treatment of tumor.

Predictive miRNAs Patterns in Blood of Breast Cancer Patients Demonstrating Resistance Towards Neoadjuvant Chemotherapy

Objective

The effect of chemotherapy in patients with breast cancer (BC) is uncertain. This study attempted to analyze serum microRNAs (miRNAs) in NAC resistant and sensitive BC patients and develop a miRNA-based nomogram model. To further help clinicians make treatment decisions for hormone receptor-positive patients.

Methods

A total of 110 BC patients with NAC were recruited and assigned in sensitive and resistant group, and 4 sensitive patients and 3 resistant patients were subjected to high-throughput sequencing. The functions of their target genes were analyzed by GO and KEGG. Five BC-related reported miRNAs were selected for expression pattern measurement by RT-qPCR and multivariate logistic analysis. The nomogram model was developed using R 4.0.1, and its predictive efficacy, consistency and clinical application value in development and validation groups were evaluated using ROC, calibration and decision curves.

Results

There were 44 differentially-expressed miRNAs in resistant BC patients. miR-3646, miR-4741, miR-6730-3p, miR-6831-5p and miR-8485 were candidate for resistance diagnosis in BC. Logistic multiple regression analysis showed that miR-4741 (or = 0.30, 95% CI = 0.08-0.63, P = 0.02) and miR-6831-5p (or = 0.48, 95% CI = 0.24-0.78, P = 0.01) were protective factors of BC resistance. The ROC curves showed a sensitivity of 0.884 and 0.750 for miR-4741 and miR-6831-5P as markers of resistance, suggesting that they can be used as independent risk factors for BC resistance. The other 3 miRNAs can be used as calibration factors to establish the risk prediction model of resistance in BC. In risk model, the prediction accuracy of resistance of BC is about 78%. 5-miRNA signature diagnostic models can help clinicians provide personalized treatment for NAC resistance BC patients to improve patient survival.

Conclusion

MiR-4741 and miR-6831-5p are independent risk factors for breast cancer resistance. This study constructed a nomogram model of NAC resistance in BC based on 5 differentially-expressed serum miRNAs.

Cancer resistance via the downregulation of the tumor suppressors RKIP and PTEN expressions: therapeutic implications

The Raf kinase inhibitor protein (RKIP) has been reported to be underexpressed in many cancers and plays a role in the regulation of tumor cells' survival, proliferation, invasion, and metastasis, hence, a tumor suppressor. RKIP also regulates tumor cell resistance to cytotoxic drugs/cells. Likewise, the tumor suppressor, phosphatase and tensin homolog (PTEN), which inhibits the phosphatidylinositol 3 kinase (PI3K)/AKT pathway, is either mutated, underexpressed, or deleted in many cancers and shares with RKIP its anti-tumor properties and its regulation in resistance. The transcriptional and posttranscriptional regulations of RKIP and PTEN expressions and their roles in resistance were reviewed. The underlying mechanism of the interrelationship between the signaling expressions of RKIP and PTEN in cancer is not clear. Several pathways are regulated by RKIP and PTEN and the transcriptional and post-transcriptional regulations of RKIP and PTEN is significantly altered in cancers. In addition, RKIP and PTEN play a key role in the regulation of tumor cells response to chemotherapy and immunotherapy. In addition, molecular and bioinformatic data revealed crosstalk signaling networks that regulate the expressions of both RKIP and PTEN. These crosstalks involved the mitogen-activated protein kinase (MAPK)/PI3K pathways and the dysregulated nuclear factor-kappaB (NF-κB)/Snail/Yin Yang 1 (YY1)/RKIP/PTEN loop in many cancers. Furthermore, further bioinformatic analyses were performed to investigate the correlations (positive or negative) and the prognostic significance of the expressions of RKIP or PTEN in 31 different human cancers. These analyses were not uniform and only revealed that there was a positive correlation between the expression of RKIP and PTEN only in few cancers. These findings demonstrated the existence of signaling cross-talks between RKIP and PTEN and both regulate resistance. Targeting either RKIP or PTEN (alone or in combination with other therapies) may be sufficient to therapeutically inhibit tumor growth and reverse the tumor resistance to cytotoxic therapies.

Comparison of PIK3CA Mutation Prevalence in Breast Cancer Across Predicted Ancestry Populations

PURPOSE

Understanding the differences in biomarker prevalence that may exist among diverse populations is invaluable to accurately forecast biomarker-driven clinical trial enrollment metrics and to advance inclusive research and health equity. This study evaluated the frequency and types of PIK3CA mutations (PIK3CAmut) detected in predicted genetic ancestry subgroups across breast cancer (BC) subtypes.

METHODS

Analyses were conducted using real-world genomic data from adult patients with BC treated in an academic or community setting in the United States and whose tumor tissue was submitted for comprehensive genomic profiling.

RESULTS

Of 36,151 patients with BC (median age, 58 years; 99% female), the breakdown by predicted genetic ancestry was 75% European, 14% African, 6% Central/South American, 3% East Asian, and 1% South Asian. We demonstrated that patients of African ancestry are less likely to have tumors that harbor PIK3CAmut compared with patients of European ancestry with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) BC (37% [949/2,593] v 44% [7,706/17,637]; q = 4.39E-11) and triple-negative breast cancer (8% [179/2,199] v 14% [991/7,072]; q = 6.07E-13). Moreover, we found that PIK3CAmut were predominantly composed of hotspot mutations, of which mutations at H1047 were the most prevalent across BC subtypes (35%-41% ER+/HER2- BC; 43%-61% HER2+ BC; 40%-59% triple-negative breast cancer).

CONCLUSION

This analysis established that tumor PIK3CAmut prevalence can differ among predicted genetic ancestries across BC subtypes on the basis of the largest comprehensive genomic profiling data set of patients with cancer treated in the United States. This study highlights the need for equitable representation in research studies, which is imperative to ensuring better health outcomes for all.

The Drosha-Independent MicroRNA6778-5p/GSK3β Axis Mediates the Proliferation of Gastric Cancer Cells

Background

Gastric cancer (GC) is a primary cause of cancer death around the world. Previous studies have found that Drosha plays a significant role in the development of tumor cells. Soon after, we unexpectedly found that the expression of microRNA6778-5p (miR6778-5p) is unconventionally high in the gastric cancer cells low-expressing Drosha. So, we designed the Drosha interference sequence and recombined it into a lentiviral vector to construct Drosha knockdown lentivirus and transfected the Drosha knockdown lentivirus into gastric cancer cells to establish Drosha knockdown gastric cancer cell lines. We aimed to explore the effect of microRNA6778-5p on the proliferation of gastric cancer cells with Drosha knockdown and its intrinsic mechanism.

Methods

We designed the Drosha interference sequence and recombined it into a lentiviral vector to construct Drosha knockdown lentivirus and transfected the Drosha knockdown lentivirus into gastric cancer cells to establish Drosha knockdown gastric cancer cell lines. After transfecting miR6778-5p mimics and inhibitor into gastric cancer cell lines with Drosha knockdown, the expression levels of miR6778-5p mimics in Drosha low-expressing gastric cancer cells increased, while miR6778-5p inhibitor decreased the expression levels of miR6778-5p. The Cell Counting Kit-8 (CCK-8) experiment was used to detect the proliferation ability of gastric cancer cells after overexpression or knockdown of miR6778-5p and bioinformatics predicted the relationship between miR6778-5p and glycogen synthase kinase-3β (GSK3β).

Results

After infection with the Drosha knockdown lentivirus, Drosha's mRNA and protein levels were significantly downregulated in gastric cancer cells. The expression levels of miR6778-5p mimics in Drosha low-expressing gastric cancer cells increased, while miR6778-5p inhibitor decreased the expression levels of miR6778-5p. Overexpression of miR6778-5p significantly enhanced the proliferation ability of Drosha low-expression gastric cancer cells; on the contrary, knocking down miR6778-5p weakened the proliferation ability of Drosha low-expression gastric cancer cells. Bioinformatics predicted that miR6778-5p targeted glycogen synthase kinase-3β (GSK3β) and the mRNA and protein levels of GSK3β decreased significantly after overexpression of miR6778-5p.

Conclusion

miR6778-5p promotes the proliferation of Drosha low-expressing gastric cancer cells by targeting GSK3β.

Decrypting a path based approach for identifying the interplay between PI3K and GSK3 signaling cascade from the perspective of cancer

Cancer is one of those leading diseases worldwide, which takes millions of lives every year. Researchers are continuously looking for specific approaches to eradicate the deadly disease, ensuring minimal adverse effects along with more therapeutic significance. Targeting of different aberrantly regulated signaling pathways, involved in cancer, is surely one of the revolutionary chemotherapeutic approach. In this instance, GSK3 and PI3K signaling cascades are considered as important role player for both the oncogenic activation and inactivation which further leads to cancer proliferation and metastasis. In this review, we have discussed the potential role of GSK3 and PI3K signaling in cancer, and we further established the crosstalk between PI3K and GSK3 signaling, through showcasing their cross activation, cross inhibition and convergence pathways in association with cancer. We also exhibited the effect of GSK3 on the efficacy of PI3K inhibitors to overcome the drug resistance and preventing the cell proliferation, metastasis in a combinatorial way with GSK3 inhibitors for a better treatment strategy in clinical settings.

Expert consensus on the clinical application of PI3K/AKT/mTOR inhibitors in the treatment of advanced breast cancer

Phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB or AKT)/mammalian target of rapamycin (mTOR) signaling pathway (PAM pathway) plays an important role in the development of breast cancer and are closely associated with the resistance to endocrine therapy in advanced breast cancer. Therefore, anticancer treatment targeting key molecules in this signaling pathway has become a research hotspot in recent years. Randomized clinical trials have demonstrated that PI3K/AKT/mTOR inhibitors bring significant clinical benefit to patients with advanced breast cancer, especially to those with hormone receptor (HR)-positive, human epidermal growth factor receptor (HER) 2-negative advanced breast cancer. Alpelisib, a PI3K inhibitor, and everolimus, an mTOR inhibitor, have been approved by FDA. Based on their high efficacy and relatively good safety profile, an expanded indication of everolimus in breast cancer has been approved by National Medical Products Administration (NMPA). Alpelisib is expected to be approved in China in the near future. The members of the consensus expert panel reached this consensus to comprehensively define the role of PI3K/AKT/mTOR signaling pathway in breast cancer, efficacy and clinical applications of PI3K/AKT/mTOR inhibitors, management of adverse reactions, and PIK3CA mutation detection, to promote the understanding of PI3K/AKT/mTOR inhibitors for Chinese oncologists, improve clinical decision-making, and prolong the survival of target patient population.

miR-107 is involved in the regulation of NEDD9-mediated invasion and metastasis in breast cancer

Background

As a metastasis-related protein, NEDD9 has been reported in breast cancer (BC) metastasis research. However, there are few studies on the upstream regulators of NEDD9, especially involving the potential role of miRNAs. The purpose of this study was to explain whether miR-107 potentially regulates NEDD9, which may lead to invasion and metastasis of BC.

Methods

MCF-7 and MDA-MB-231 cells were transduced with lentiviruses to construct stably transduced cells with miR-107 overexpression, miR-107 silencing or empty vectors. A luciferase reporter assay was performed to verify the binding of miR-107 and NEDD9. The scratch test and Transwell assay were used to measure cell migration and invasion ability, respectively. For the study of metastasis in vivo, we injected MDA-MB-231 cells into the fat pad of nude mice to develop an orthotopic breast cancer model.

Results

We found that NEDD9 expression correlates with the prognosis of BC patients. In BC cell lines, NEDD9 was positively correlated with cell migration ability. Further research revealed that miR-107 inhibited NEDD9 expression by targeting the 3′-untranslated region of NEDD9. Overexpression of miR-107 suppressed the expression of NEDD9, thereby inhibiting the invasion, migration and proliferation of BC cells, but interference with miR-107 promoted the expression of NEDD9 as well as invasion, migration and proliferation. In an in vivo model, overexpression of miR-107 decreased the expression of NEDD9 and inhibited tumour growth, invasion and metastasis; however, these effects were reversed by inhibiting miR-107.

Conclusions

These findings indicated the potential role of miR-107 in regulating NEDD9 in the invasion, migration and proliferation of BC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09603-3.

Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Solamargine Inhibits Prostate Cancer Cell Growth and Enhances the Therapeutic Efficacy of Docetaxel via Akt Signaling

Prostate cancer (PCa) has become a leading cause of cancer-associated incidence and mortality in men worldwide. However, most primary PCas relapse to castration-resistant PCa (CRPC) after androgen deprivation treatment. The current treatment for CRPC is based on chemotherapeutic drugs such as docetaxel, while the development of chemoresistance and severe side effects limit the therapeutic benefit. Solamargine, a natural alkaloid isolated from a traditional Chinese herbal medicine known as Solanum nigrum, exhibits antitumor activity in various human cancers. In this study, we demonstrated that solamargine substantially inhibited CRPC cell growth in a dose-dependent manner through the suppression of phosphoinositide 3-kinase (PI3K)/Akt signaling. Moreover, solamargine exhibited significant antitumor effects in mouse xenograft models. Bioinformatics analysis of docetaxel-resistant PCa cells indicated that the PI3K/Akt pathway mediated the chemoresistance of CRPC. Furthermore, solamargine significantly enhanced the efficacy of docetaxel in PCa cells. These results reveal the therapeutic potential of solamargine against human PCa.

Protein Kinase A Downregulation Delays the Development and Progression of Polycystic Kidney Disease

Background: Upregulation of cAMP-dependent and -independent PKA signaling is thought to promote cystogenesis in polycystic kidney disease (PKD). PKA-I regulatory subunit RIα is increased in kidneys of orthologous mouse models. Kidney-specific knockout of RIα upregulates PKA activity, induces cystic disease in wild-type mice, and aggravates it in Pkd1 ^RC/RC mice. Methods: PKA-I activation or inhibition was compared to EPAC activation or PKA-II inhibition using Pkd1 ^RC/RC metanephric organ cultures. The effect of constitutive PKA (preferentially PKA-I) downregulation in vivo was ascertained by kidney-specific expression of a dominant negative RIαB allele in Pkd1 ^RC/RC mice obtained by crossing Prkar1α ^R1αB/WT, Pkd1 ^RC/RC, and Pkhd1-Cre mice (C57BL/6 background). The effect of pharmacologic PKA inhibition using a novel, selective PRKACA inhibitor (BLU2864) was tested in mIMCD3 3D cultures, metanephric organ cultures, and Pkd1 ^RC/RC mice on a C57BL/6 x 129S6/Sv F1 background. Mice were sacrificed at 16 weeks of age. Results: PKA-I activation promoted and inhibition prevented ex vivo P-Ser133 CREB expression and cystogenesis. EPAC activation or PKA-II inhibition had no or only minor effects. BLU2864 inhibited in vitro mIMCD3 cystogenesis and ex vivo P-Ser133 CREB expression and cystogenesis. Genetic downregulation of PKA activity and BLU2864 directly and/or indirectly inhibited many pro-proliferative pathways and were both protective in vivo BLU2864 had no detectable on- or off-target adverse effects. Conclusions: PKA-I is the main PKA isozyme promoting cystogenesis. Direct PKA inhibition may be an effective strategy to treat PKD and other conditions where PKA signaling is upregulated. By acting directly on PKA, the inhibition may be more effective than or substantially increase the efficacy of treatments that only affect PKA activity by lowering cAMP.

Inhibition of Musashi-1 enhances chemotherapeutic sensitivity in gastric cancer patient-derived xenografts

Musashi-1 (MSI1), a neural RNA-binding protein, is considered a gastric and intestinal stem cell marker. Although the function of MSI1 in gastric cancer has attracted increasing interest, it is not known whether MSI1 can be used as a biomarker to monitor gastric cancer development and response to treatment. Here, the role of MSI1 in the chemotherapeutic sensitivity of gastric cancer was investigated. Patients with high MSI1 levels had poor outcomes, implicating the gene in the development and progression of the disease. We overexpressed and silenced MSI1 in the human gastric cancer cell lines MKN45 and HGC27, finding that knockdown reduced proliferation, invasion, and migration, while promoting apoptosis. A patient-derived xenograft gastric cancer model was constructed in which mice received chemical drugs, si-MSI1, or a drug-si-MSI1 combination. It was found that blocking MSI1 expression reduced gastric cancer drug tolerance. The combination treatment with si-MSI1 was superior to 5F-dUMP and cisplatin, either separately or in combination, indicating that including si-MSI1 was better than drug therapy alone. Transcriptome sequencing analysis showed that MSI1 altered cell cycle regulation and growth signal transduction, including that of blood vessel epicardial substance (BVES). These results suggest that MSI1 reduces the tolerance of gastric cancer to chemical drugs through modulation of MSI1/BVES signaling.

Shedding New Light on Methylmercury-induced Neurotoxicity Through the Crosstalk Between Autophagy and Apoptosis

Methylmercury (MeHg) is a bio-accumulative global environmental contaminant present in fish and seafood. MeHg accumulates in the aquatic environment and eventually reaches the human system via the food chain by bio-magnification. The central nervous system is the primary target of toxicity and is particularly vulnerable during development. It is well documented that developmental MeHg exposure can lead to neurological alterations, including cognitive and motor dysfunction. Apoptosis is a primary characteristic of MeHg-induced neurotoxicity, and may be regulated by autophagic activity. However, mechanisms mediating the interaction between apoptosis and autophagy remains to be explored. Autophagy is an adaptive response under stressful conditions, and the basal level of autophagy ensures the physiological turnover of old and damaged organelles. Autophagy can regulate cell fate through different crosstalk signaling pathways. A complex interplay between autophagy and apoptosis determines the degree of apoptosis and the progression of MeHg-induced neurotoxicity as demonstrated by pre-clinical models and clinical trials. This review summarizes recent advances in the roles of autophagy and apoptosis in MeHg neurotoxicity and thoroughly explores the relationship between them. The autophagic pathway may be a potential therapeutic target in MeHg neurotoxicity through modulation of apoptosis.

The E3 Ubiquitin Ligase HOIP inhibits Cancer Cell Apoptosis via modulating PTEN stability

Chemotherapy is widely used in a variety of solid tumors, such as lung cancer, gastric cancer and breast cancer. The genotoxic drugs, such as cisplatin, suppress cancer progression either by inhibition cell proliferation or facilitating apoptosis. However, the chemotherapy resistance remains an urgent challenge in cancer therapy, especially in advanced stages. Several studies showed that the activation of pro-survival pathways, such as PI3K-AKT, participated in mediating chemotherapy resistance. The insights into the molecular mechanisms for underlying chemotherapy resistance are of great importance to improve cancer patient survival in advanced stages. The HOIP protein belongs to the RING family E3 ubiquitin ligases and modulates several atypical ubiquitination processes in cellular signaling. Previous studies showed that HOIP might be an important effector in modulating cancer cell death under genotoxic drugs. Here, we report that HOIP associates with PTEN and facilitates PTEN degradation in cancer cells. Depletion of HOIP causes cell cycle arrest and apoptosis, which effects could be rescued by PTEN silencing. Besides, the survival data from public available database show that HOIP expression correlates with poor survival in several types of chemotherapy-treated cancer patients. In conclusion, our study establishes a novel mechanism by which HOIP modulates PTEN stability and facilitates chemotherapy resistance in malignancies.

O2-(2,4-dinitrophenyl) diazeniumdiolate derivative induces G2/M arrest via PTEN-mediated inhibition of PI3K/Akt pathway in hepatocellular carcinoma cells

OBJECTIVES

The study aimed to investigate whether G2/M arrest caused by O2-(2,4-dinitrophenyl) diazeniumdiolate derivative (JS-K) was related to PTEN-mediated inhibition of PI3K/Akt pathway in hepatocellular carcinoma cells.

METHODS

The cell apoptosis was detected by DAPI staining and Annexin V-FITC/PI dual staining. The cell cycle was analysed by PI staining. The expressions of cell cycle-related proteins, PTEN and PI3K/AKT pathway were measured by Western blot. The rat model of primary hepatic carcinoma was established with diethylnitrosamine to verify the antitumour effects of JS-K.

KEY FINDINGS

The morphological features of apoptosis were obviously reversed when the cells were pre-treated with bpv(pic), followed by treatment with JS-K. JS-K mediated G2/M arrest and down-regulated expressions of cyclin B1. Meanwhile, it up-regulated the expression of p-Cdk1, p-Chk2 and p-CDC25C while down-regulated that of Cdk1 and CDC25C. Furthermore, JS-K also enhanced the expressions of p21 and p27, PTEN and p53 while decreased the expressions of p-PTEN, PI3K and p-AKT. However, bpv(pic) and Carboxy-PTIO could reverse JS-K-induced G2/M cell arrest and PTEN-mediated inhibition of the PI3K/AKT pathway. The same results were also testified in the rat model of primary hepatic carcinoma.

CONCLUSIONS

JS-K caused G2/M arrest through PTEN-mediated inhibition of the PI3K/AKT pathway involving Chk2/CDC25C/Cdk1 checkpoint.

Integrative cBioPortal Analysis Revealed Molecular Mechanisms That Regulate EGFR-PI3K-AKT-mTOR Pathway in Diffuse Gliomas of the Brain

Simple Summary

The current classification of central nervous system tumors has incorporated molecular changes that have clarified biological behavior and categorized gliomas into different types and malignancy grades. The most malignant type—glioblastoma, represents one of the most therapeutically challenging tumors, with a median survival of only 12–14 months despite trimodal therapy. In our integrative large-scale study, we used genomics, transcriptomics, epigenomics, and proteomics to investigate and make sense of the molecular changes that activate or inhibit the EGFR-PI3K-AKT-mTOR signaling pathway. Different pathohistological types of diffuse brain gliomas harbored distinct changes. A better understanding of signaling pathway regulation helps to the discovery of new targets for glioma therapies. Our results have potential for diagnostics improvement and tailored therapies.

Abstract

Diffuse gliomas are a heterogeneous group of tumors with aggressive biological behavior and a lack of effective treatment methods. Despite new molecular findings, the differences between pathohistological types still require better understanding. In this in silico analysis, we investigated AKT1, AKT2, AKT3, CHUK, GSK3β, EGFR, PTEN, and PIK3AP1 as participants of EGFR-PI3K-AKT-mTOR signaling using data from the publicly available cBioPortal platform. Integrative large-scale analyses investigated changes in copy number aberrations (CNA), methylation, mRNA transcription and protein expression within 751 samples of diffuse astrocytomas, anaplastic astrocytomas and glioblastomas. The study showed a significant percentage of CNA in PTEN (76%), PIK3AP1 and CHUK (75% each), EGFR (74%), AKT2 (39%), AKT1 (32%), AKT3 (19%) and GSK3β (18%) in the total sample. Comprehensive statistical analyses show how genomics and epigenomics affect the expression of examined genes differently across various pathohistological types and grades, suggesting that genes AKT3, CHUK and PTEN behave like tumor suppressors, while AKT1, AKT2, EGFR, and PIK3AP1 show oncogenic behavior and are involved in enhanced activity of the EGFR-PI3K-AKT-mTOR signaling pathway. Our findings contribute to the knowledge of the molecular differences between pathohistological types and ultimately offer the possibility of new treatment targets and personalized therapies in patients with diffuse gliomas.

A pharmacophore-based classification better predicts the outcomes of HER2-negative breast cancer patients receiving the anthracycline- and/or taxane-based neoadjuvant chemotherapy

AIMS

Prognosis of patients for human epidermal growth factor receptor 2 (HER2)-negative breast cancer post neoadjuvant chemotherapy is not well understood. The aim of this study was to develop a novel pharmacophore-based signature to better classify and predict the risk of HER2-negative patients after anthracycline-and/or taxane-based neoadjuvant chemotherapy (NACT).

MAIN METHODS

Anthracycline and taxane pharmacophore-based genes were obtained from PharmMapper. Drug-targeted genes (DTG) related clinical and bioinformatic analyses were undertaken in four GEO datasets.

KEY FINDINGS

We used 12 genes from the pharmacophore to develop a DTG score (DTG-S). The DTG-S classification exhibited significant prognostic ability with respect to disease free survival (DFS) for HER2-negative patients who receive at least one type of neoadjuvant chemotherapy that included anthracycline and/or taxane. DTG-S associated with a high predictive ability for pathological complete response (pCR) as well as for prognosis of breast cancer. Using the DTG-S classification in other prediction models may improve the reclassification accuracy for DFS. Combining the DTG-S with other clinicopathological factors may further improve its predictive ability of patients' outcomes. Gene ontology and KEGG pathway analysis showed that the biological processes of DTG-S high group were associated with the cell cycle, cell migration, and cell signal transduction pathways. Targeted drug analysis shows that some CDK inhibitors and PI3K-AKT pathway inhibitors may be useful for high DTG-S patients.

SIGNIFICANCE

The DTG-S classification adds prognostic and predictive information to classical parameters for HER2-negative patients who receive anthracycline-and/or taxane-based NACT, which could improve the patients' risk stratification and may help guide adjuvant treatment.

TASP1 Promotes Proliferation and Migration in Gastric Cancer via EMT and AKT/P-AKT Pathway

Threonine aspartase 1 (TASP1) was reported to function in the development of cancer. However, the regulatory mechanism of TASP1 in gastric cancer (GC) remains unclear. In this study, we determined the expression of TASP1 in tissues of GC patients, GC cells by qRT-PCR, and western blot and assessed the relationship between TASP1 and GC cell proliferation and migration via CCK-8 and transwell assay. It was found that the expression of TASP1 in GC tissues or GC cell lines was significantly higher than that in normal adjacent tissues or normal cells. The proliferation and migration of GC cells were inhibited upon TASP1 knockdown. Mechanism investigation revealed that TASP1 promoted GC cell proliferation and migration through upregulating the p-AKT/AKT expression. TASP1 induced GC cell migration via the epithelial -mesenchymal transition (EMT) pathway. In conclusion, TASP1 promotes GC progression through the EMT and AKT/p-AKT pathway, and it may serve as a new potential biomarker and therapeutic target for GC.

Activation of PI3K/AKT/mTOR Pathway Causes Drug Resistance in Breast Cancer

Although chemotherapy, targeted therapy and endocrine therapy decrease rate of disease recurrence in most breast cancer patients, many patients exhibit acquired resistance. Hyperactivation of the PI3K/AKT/mTOR pathway is associated with drug resistance and cancer progression. Currently, a number of drugs targeting PI3K/AKT/mTOR are being investigated in clinical trials by combining them with standard therapies to overcome acquired resistance in breast cancer. In this review, we summarize the critical role of the PI3K/AKT/mTOR pathway in drug resistance, the development of PI3K/AKT/mTOR inhibitors, and strategies to overcome acquired resistance to standard therapies in breast cancer.

Kinase GSK3β functions as a suppressor in colorectal carcinoma through the FTO-mediated MZF1/c-Myc axis

Colorectal carcinoma (CRC) poses heavy burden to human health and has an increasing incidence. Currently, the existing biomarkers for CRC bring about restrained clinical benefits. GSK3β is reported to be a novel therapeutic target for this disease but with undefined molecular mechanisms. Thus, we aimed to investigate the regulatory effect of GSK3β on CRC progression via FTO/MZF1/c-Myc axis. Firstly, the expression patterns of GSK3β, FTO, MZF1 and c-Myc were determined after sample collection. Lowly expressed GSK3β but highly expressed FTO, MZF1 and c-Myc were found in CRC. After transfection of different overexpressed and interference plasmids, the underlying mechanisms concerning GSK3β in CRC cell functions were analysed. Additionally, the effect of GSK3β on FTO protein stability was assessed followed by detection of MZF1 m6A modification and MZF1-FTO interaction. Mechanistically, GSK3β mediated ubiquitination of demethylase FTO to reduce FTO expression. Besides, GSK3β inhibited MZF1 expression by mediating FTO-regulated m6A modification of MZF1 and then decreased the proto-oncogene c-Myc expression, thus hampering CRC cell proliferation. We also carried out in vivo experiment to verify the regulatory effect of GSK3β on CRC via FTO-mediated MZF1/c-Myc axis. It was found that GSK3β inhibited CRC growth in vivo which was reversed by overexpressing c-Myc. Taken together, our findings indicate that GSK3β suppresses the progression of CRC through FTO-regulated MZF1/c-Myc axis, shedding light onto a new possible pathway by which GSK3β regulates CRC.

Identification of an antitumor effect of demethylzeylasteral on human gastric cancer cells

Gastric cancer is a common malignancy in China, with the second highest mortality rate worldwide. Advanced gastric cancer usually exhibits a poor prognosis with a low 5-year survival rate. Therefore, developing novel drugs for the treatment of this cancer will be beneficial for patients. Demethylzeylasteral, an extract of tripterygium wilfordii, has shown positive anticancer activities. However, the possible antitumor effect of demethylzeylasteral on gastric cancer cells and its underlying molecular mechanism remain to be determined. In the present study, the Cell Counting Kit-8 and colony formation assays revealed that demethylzeylasteral impeded the proliferation of human gastric cancer cells in a dose-dependent manner. Furthermore, the Transwell assay identified an inhibitory effect of demethylzeylasteral on the migration of MKN-45 cells, while flow cytometry found that treatment with demethylzeylasteral induced apoptosis and decreased the mitochondrial membrane potential in the cancer cells. Further investigation revealed that demethylzeylasteral downregulated the phosphorylation of ERK1/2, AKT, and GSK-3β in MKN-45 cells. Notably, decreased expression of Bcl-2 and increased expression of Bax, cleaved caspase-3, cleaved caspase-9 and cleaved PARP were detected in the cancer cells treated with demethylzeylasteral. The present study demonstrated that demethylzeylasteral exhibits therapeutic potential for gastric cancer.

Paired‑related homeobox 1 overexpression promotes multidrug resistance via PTEN/PI3K/AKT signaling in MCF‑7 breast cancer cells

Multidrug resistance (MDR) is a major cause of disease relapse and mortality in breast cancer. Paired‑related homeobox 1 (PRRX1) is associated with the epithelial‑mesenchymal transition (EMT), which is involved in tumor development, including cell invasion and MDR. However, the effect of PRRX1 on MDR had not clearly established. The present study investigated the influence of PRRX1 on MDR and the underlying molecular mechanisms in MCF‑7 breast cancer cells. MCF‑7 cells were divided into PRRX1+ group (cells transfected with a recombinant plasmid carrying the PRRX1 gene), negative control group (cells transfected with a blank vector) and blank group (untreated cells). It was found that the relative protein and mRNA expression levels of PRRX1, N‑cadherin, vimentin and P‑glycoprotein were significantly higher in PRRX1‑overexpressing MCF‑7 cells compared with those in control cells. The half‑maximal inhibitory concentration of three groups after treatment with docetaxel and cis‑platinum complexes were significantly higher in PRRX1‑overexpressing MCF‑7 cells compared with those in control cells. Furthermore, relative PTEN expression decreased significantly and levels of phosphorylated PI3K and AKT increased substantially in PRRX1‑overexpressing MCF‑7 cells. These results indicated that PRRX1 overexpression may induce MDR via PTEN/PI3K/AKT signaling in breast cancer. It is highly recommended that PRRX1 gene expression detection should be performed in patients with breast cancer to aid the selection of more appropriate treatments, which will lead to an improved prognosis in clinical practice.

Molecular Mechanism of Helicobacter pylori-Induced Gastric Cancer

Introduction

Various types of cancers threaten human life. The role of bacteria in causing cancer is controversial, but it has been determined that the Helicobacter pylori infection is one of the identified risk factors for gastric cancer. Helicobacter pylori infection is highly prevalent, and about half of the world^,s population is infected with it.

Objective

The aim of this study was the role of Helicobacter pylori in the development of gastric cancer.

Method

We obtained information from previously published articles.

Results and Conclusion

The bacterium has various virulence factors, including cytotoxin- associated gene A, vacuolating cytotoxin A, and the different outer membrane proteins that cause cancer by different mechanisms. These virulence factors activate cell signaling pathways such as PI3-kinase/Akt, JAK/STAT and Ras, Raf, and ERK signaling that control cell proliferation. Uncontrolled proliferation can lead to cancer.

Glycogen Synthase Kinase 3β in Cancer Biology and Treatment

Glycogen synthase kinase (GSK)3β is a multifunctional serine/threonine protein kinase with more than 100 substrates and interacting molecules. GSK3β is normally active in cells and negative regulation of GSK3β activity via phosphorylation of its serine 9 residue is required for most normal cells to maintain homeostasis. Aberrant expression and activity of GSK3β contributes to the pathogenesis and progression of common recalcitrant diseases such as glucose intolerance, neurodegenerative disorders and cancer. Despite recognized roles against several proto-oncoproteins and mediators of the epithelial–mesenchymal transition, deregulated GSK3β also participates in tumor cell survival, evasion of apoptosis, proliferation and invasion, as well as sustaining cancer stemness and inducing therapy resistance. A therapeutic effect from GSK3β inhibition has been demonstrated in 25 different cancer types. Moreover, there is increasing evidence that GSK3β inhibition protects normal cells and tissues from the harmful effects associated with conventional cancer therapies. Here, we review the evidence supporting aberrant GSK3β as a hallmark property of cancer and highlight the beneficial effects of GSK3β inhibition on normal cells and tissues during cancer therapy. The biological rationale for targeting GSK3β in the treatment of cancer is also discussed at length.

GSK-3β in DNA repair, apoptosis, and resistance of chemotherapy, radiotherapy of cancer

Glycogen synthase kinase-3β (GSK-3β) is an evolutionarily conserved serine/threonine kinase, functioning in numerous cellular processes including cell proliferation, DNA repair, cell cycle, signaling and metabolic pathways. GSK-3β is implicated in different diseases including inflammation, neurodegenerative disease, diabetes and cancers. GSK-3β is involved in biological processes of tumorigenesis, therefore, it is rational that GSK-3β inhibitors were employed to target malignant tumors. The effects of GSK-3β inhibitors in combination of radiation and chemotherapeutic drugs have been reported in various types of cancers, suggesting GSK-3β would play important roles in cancer treatments. GSK-3β is involved in multiple signal pathway including Wnt/β-catenin, PI3K/PTEN/AKT and Notch. GSK-3β also functions in DNA repair through phosphorylation of DNA repair factors and affecting their binding to chromatin. This review focuses on the molecular mechanism of GSK-3β in DNA repair, special in base excision repair and double-strands break repair, the roles of GSK-3β in inhibition of apoptosis through activation of NF-κB, and the effects of GSK-3β inhibitors on radio- and chemosensitization of various types of cancers. This article is part of a Special Issue entitled: GSK-3 and related kinases in cancer, neurological and other disorders edited by James McCubrey, Agnieszka Gizak and Dariusz Rakus.

miR106a Promotes the Growth of Transplanted Breast Cancer and Decreases the Sensitivity of Transplanted Tumors to Cisplatin

Objective

To explore the effect of miR106a on the growth of breast cancer xenografts and the sensitivity of chemotherapeutic agents.

Methods

Breast cancer cell lines (MDA-MB231 and MCF7) were transfected with an miR106 mimic and miR106a inhibitor. BALB/c female nude mice were selected to construct a transplanted-tumor model. Cisplatin treatment was performed 2 weeks after inoculation. After 5 weeks, tumor tissue was weighed. Apoptosis of tumor cells was detected by TUNEL staining. The expression of these proteins (Ki67, β-catenin, cyclin D1 and cMyc) was detected by immunohistochemistry. The contents of P53, RUNX3, ABCG2, β-catenin, BAX, and BCL2 mRNA were detected by qRT-PCR.

Results

The miR106a mimic (MM) group’s tumor volume and weight were significantly bigger than those of the model group. miR106a mRNA content was higher than the blank control group, and β-catenin and Ki67 protein were strongly positive. β-catenin, BCL2, and ABCG2 mRNA content was were increased. P53, BAX, and RUNX3 mRNA content was decreased. The number of positive cells on TUNEL staining was significantly lower in the miR106a inhibitor (MI) group. After cisplatin treatment, inhibition of tumor growth was most obvious in the MI+DDP (cisplatin) group. Compared with the MM group, tumor growth in the MM+FH535 (Wnt-pathway inhibitor) group was significantly lower, and Wnt-pathway activity was decreased.

Conclusion

Overexpression of miR106a can promote the growth of transplanted breast cancer and decrease the sensitivity of transplanted tumors to cisplatin. The mechanism may be related to abnormal activation of the Wnt-signaling pathway.

Screening of Pleural Mesothelioma Cell Lines for Kinase Activity May Identify New Mechanisms of Therapy Resistance in Patients Receiving Platin-Based Chemotherapy

Background

Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumor associated with a dismal prognosis. Multimodal therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons underlying the rather poor efficacy of platinum compounds remain largely unknown. Kinase activity might influence cellular response to these regimens.

Materials and Methods

For this exploratory study, we screened MPM cell lines (NCI-H2452, NCI-H2052, and MSTO-211H) differing in response to cisplatin and benign control fibroblasts (MRC-5) for overall phosphorylation patterns as well as kinase activity with respect to cellular response to cisplatin-based therapeutics. We analysed the cell lines for cellular kinases in a high-throughput manner using the highly innovative technique PamGene. Cell state analysis including apoptosis, necrosis, and cell viability was performed by using enzyme activity and fluorescent-based assays.

Results

Cisplatin alters cellular phosphorylation patterns affecting cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis. In cisplatin-responsive cell lines, phosphorylation of AKT1 and GSK3B was decreased but could not be influenced in cisplatin-resistant NCI-H2452 cells. Cisplatin-responsive cell lines showed increased phosphorylation levels of JNK1/2/3 but decreased phosphorylation in cisplatin-resistant NCI-H2452 cells.

Conclusion

Kinase phosphorylation and activity might play a crucial role in cellular response to cytostatic agents. Cisplatin influences phosphorylation patterns with distinct features in cisplatin-resistant cells. These alterations exert a significant impact on cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis of the respective tumor cells. Based on our results, the induction of p38 or JNK1/3, or inhibition of AKT1 by, for example, BIA-6, might offer a positive synergistic effect by induction of an apoptotic response to cisplatin-based treatment, thus potentially enhancing the clinical outcome of MPM patients.

Up-regulation of SPC25 promotes breast cancer

In this study, expression of the SPC25 gene was characterized in breast cancer (BC), and its effects on BC development and progression, functions in BC cells, and potential underlying mechanisms were examined. Data from TCGAportal and FIREBROWSE indicated that SPC25 was upregulated in BC tissues compared to normal tissues, and CANCERTOOL indicated that higher SPC25 mRNA levels were associated with increased probability of recurrence and poorer survival in BC patients. BC patients with higher SPC25 expression displayed shorter distant metastasis-free survival, relapse-free survival, and overall survival. Colony formation and CCK-8 experiments confirmed that SPC25 promoted proliferation of BC cells. Single-cell analysis indicated that SPC25 is associated with cell cycle regulation, DNA damage and repair, and BC cell proliferation. SPC25 knockdown suppressed proliferation of BC cells. MiRNAs, circRNAs, RNA-binding proteins, transcription factors, and immune factors that might interact with SPC25 mRNA to promote BC were also identified. These findings suggest that SPC25 levels are higher in more malignant BC subtypes and are associated with poor prognosis in BC patients. In addition, DNA methyltransferase inhibitor and transcription factors inhibitor treatments targeting SPC25 might improve survival in BC patients.