Deregulated PTEN/PI3K/AKT/mTOR signaling in prostate cancer: Still a potential druggable target?

Mussel-inspired protein-based nanoparticles for curcumin encapsulation and promoting antitumor efficiency

Curcumin demonstrated therapeutic potential for cancer. However, its medical application is limited due to low solubility, poor stability and low absorption rate. Here, we used the mussel-inspired functional protein (MPKE) to fabricate the curcumin-carrying nanoparticle (Cur-MPKE) for encapsulating and delivering curcumin. The protein MPKE is composed of the mussel module and zwitterionic peptide. The Dopa group bonding characteristic of the mussel module was leveraged for the self-assembly of nanoparticles, while the superhydrophilic property of the zwitterionic peptide was utilized to enhance the stability of nanoparticles. As expected, MPKE and Cur are tightly bound through hydrogen bonds and dynamic imide bonds to form nanoparticles. Cur-MPKE showed improved solubility and stability in aqueous solutions as well as excellent biocompatibility. Besides, Cur-MPKE also exhibited pH-triggered release and enhanced uptake of curcumin by tumor cells, promoting the antioxidant activity and antitumor effect of curcumin. Moreover, systemic experiments of Cur-MPKE to rats demonstrated that Cur-MPKE significantly inhibited tumor tissue growth and proliferation without causing obvious systemic toxicity. This work provides a new strategy for fabricating the delivery system of curcumin with improved stability, sustainability and bioavailability.

DEAD-Box Helicase 17 circRNA (circDDX17) Reduces Sorafenib Resistance and Tumorigenesis in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of liver malignancy. Despite significant progress in HCC treatment, resistance to chemotherapy and tumor metastasis are the main reasons for the unsatisfactory prognosis of HCC. Circular RNAs (circRNAs) have been extensively documented to play a role in the development of various types of cancer.

AIMS

Here, we investigated the role of DEAD-box helicase 17 circRNA (circDDX17) in HCC and its underlying molecular mechanisms.

METHODS

Our research employed various techniques including reverse transcription-quantitative polymerase chain reaction (RT-qPCR), cell counting kit-8 (CCK-8), flow cytometry, dual luciferase reporter assay, RNA immunoprecipitation (RIP), and western blot analysis. Additionally, we conducted a tumor xenograft assay to investigate the in vivo function of circDDX17.

RESULTS

Firstly, the expression of circDDX17 was downregulated in HCC tissues and cells. Through functional experiments, it was observed that the overexpression of circDDX17 enhanced the sensitivity of sorafenib, promoted apoptosis, and inhibited the process of epithelial-mesenchymal transition (EMT) in vitro. Additionally, in vivo studies revealed that circDDX17 reduced tumor growth and increased sorafenib sensitivity. Mechanically, circDDX17 competitively combined miR-21-5p to suppress PTEN expression and activate the PI3K/AKT pathway. Furthermore, our rescue assays demonstrated that circDDX17 act as a tumor suppressor by blocking sorafenib resistance and tumorigenesis, while the inhibitory effect caused by circDDX17 upregulation was neutralized when miR-21-5p was overexpressed, PTEN was silenced, or the PI3K/AKT pathway was activated.

CONCLUSION

Our findings firstly confirmed that circDDX17 suppressed sorafenib resistance and HCC progression by regulating miR-21-5p/PTEN/PI3K/AKT pathway, which may provide novel biomarkers for the diagnosis, treatment and prognosis of HCC.

Mitochondrial transfer in tunneling nanotubes-a new target for cancer therapy

A century ago, the Warburg effect was first proposed, revealing that cancer cells predominantly rely on glycolysis during the process of tumorigenesis, even in the presence of abundant oxygen, shifting the main pathway of energy metabolism from the tricarboxylic acid cycle to aerobic glycolysis. Recent studies have unveiled the dynamic transfer of mitochondria within the tumor microenvironment, not only between tumor cells but also between tumor cells and stromal cells, immune cells, and others. In this review, we explore the pathways and mechanisms of mitochondrial transfer within the tumor microenvironment, as well as how these transfer activities promote tumor aggressiveness, chemotherapy resistance, and immune evasion. Further, we discuss the research progress and potential clinical significance targeting these phenomena. We also highlight the therapeutic potential of targeting intercellular mitochondrial transfer as a future anti-cancer strategy and enhancing cell-mediated immunotherapy.

The Therapeutic Efficacy and Mechanism of Action of Gnetin C, a Natural Compound from the Melinjo Plant, in a Preclinical Mouse Model of Advanced Prostate Cancer

The metastasis-associated protein 1/protein kinase B (MTA1/AKT) signaling pathway has been shown to cooperate in promoting prostate tumor growth. Targeted interception strategies by plant-based polyphenols, specifically stilbenes, have shown great promise against MTA1-mediated prostate cancer progression. In this study, we employed a prostate-specific transgenic mouse model with MTA1 overexpression on the background of phosphatase and tensin homolog (Pten) null (R26MTA1; Ptenf/f) and PC3M prostate cancer cells which recapitulate altered molecular pathways in advanced prostate cancer. Mechanistically, the MTA1 knockdown or pharmacological inhibition of MTA1 by gnetin C (dimer resveratrol) in cultured PC3M cells resulted in the marked inactivation of mammalian target of rapamycin (mTOR) signaling. In vivo, mice tolerated a daily intraperitoneal treatment of gnetin C (7 mg/kg bw) for 12 weeks without any sign of toxicity. Treatment with gnetin C markedly reduced cell proliferation and angiogenesis and promoted apoptosis in mice with advanced prostate cancer. Further, in addition to decreasing MTA1 levels in prostate epithelial cells, gnetin C significantly reduced mTOR signaling activity in prostate tissues, including the activity of mTOR-target proteins: p70 ribosomal protein S6 kinase (S6K) and eukaryotic translational initiation factor 4E (elF4E)-binding protein 1 (4EBP1). Collectively, these findings established gnetin C as a new natural compound with anticancer properties against MTA1/AKT/mTOR-activated prostate cancer, with potential as monotherapy and as a possible adjunct to clinically approved mTOR pathway inhibitors in the future.

Targeting the PI3K/AKT signaling pathway in anticancer research: a recent update on inhibitor design and clinical trials (2020-2023)

INTRODUCTION

Recent years have witnessed great achievements in drug design and development targeting the phosphatidylinositol 3-kinase/protein kinase-B (PI3K/AKT) signaling pathway, a pathway central to cell growth and proliferation. The nearest neighbor protein-protein interaction networks for PI3K and AKT show the interplays between these target proteins which can be harnessed for drug discovery. In this review, we discuss the drug design and clinical development of inhibitors of PI3K/AKT in the past three years. We review in detail the structures, selectivity, efficacy, and combination therapy of 35 inhibitors targeting these proteins, classified based on the target proteins. Approaches to overcoming drug resistance and to minimizing toxicities are discussed. Future research directions for developing combinational therapy and PROTACs of PI3K and AKT inhibitors are also discussed.

AREA COVERED

This review covers clinical trial reports and patent literature on inhibitors of PI3K and AKT published between 2020 and 2023.

EXPERT OPINION

To address drug resistance and drug toxicity of inhibitors of PI3K and AKT, it is highly desirable to design and develop subtype-selective PI3K inhibitors or subtype-selective AKT1 inhibitors to minimize toxicity or to develop allosteric drugs that can form covalent bonds. The development of PROTACs of PI3Kα or AKT helps to reduce off-target toxicities.

Pharmacogenetic study of phosphatase and tensin homolog polymorphism (rs701848) in childhood epilepsy: relation to circulating Wnt signaling

OBJECTIVE

The present study aimed at evaluating the potential contribution of Phosphatase and Tensin Homolog (PTEN) and its gene polymorphism (PTEN rs701848 T/C) in relation to Wingless/integrase-1 (Wnt) signaling in childhood epilepsy and the impact of antiepileptic medications on their serum levels.

METHODS

This study included 100 children with epilepsy (50 pharmacoresistant and 50 pharmacoresponsive) and 50 matched controls. All subjects had their genotypes for the PTEN rs701848T/C polymorphism assessed using TaqManTM assays and real-time PCR. By using the sandwich ELISA technique, the blood concentrations of PTEN and Wnt3a were measured.

RESULTS

Serum Wnt3a levels in epileptic patients were significantly higher than in the control group, p < 0.001. Children with epilepsy who received oxcarbazepine had considerably lower serum Wnt3a levels than those who didn't, p < 0.001.With an AUC of 0.71, the cutoff value for diagnosing epilepsy as serum Wnt3a > 6.2 ng/mL has a sensitivity of 55% and a specificity of 80%. When compared to controls, epileptic children had considerably more (TT) genotype and less (TC and CC) genotypes, p < 0.05 for all. Epileptic children had significantly higher (T) allele frequency than controls, p = 0.006 with OR (95%CI) = 1.962(1.206-3.192). Pharmacoresistant epileptic children had significantly higher (TT) genotype compared to pharmacoresponsive type (p = 0.020).

CONCLUSION

We originally found a strong association between PTEN rs701848 T/C and childhood epilepsy, in particular pharmacoresistant type. Serum Wnt3a levels increased in epilepsy, but were not significantly different between different alleles of PTEN. In pharmaco-responsive children Wnt3a levels differed significantly between the different PTEN genotypes. Antiepileptics may affect Wnt3a levels.

Elucidation of the Role of the Epigenetic Regulatory Mechanisms of PI3K/Akt/mTOR Signaling Pathway in Human Malignancies

The PI3K/Akt/mTOR pathway modulates cell growth, proliferation, metabolism, and movement. Moreover, significant studies have shown that the genes involved in this pathway are frequently activated in human cancer. Observational and computational modeling of the PI3K/AKt/ mTOR pathway inhibitors has been explored in clinical trials. It has been observed that the effectiveness and safety evidence from clinical studies and various inhibitors of this route have been given FDA approval. In this review article, we focused on the processes behind the overactivation of PI3K/Akt/mTOR signaling in cancer and provided an overview of PI3K/Akt/mTOR inhibitors as either individual drugs or a combination of different doses of drugs for different types of cancer. Furthermore, the review discusses the biological function and activation of the PI3K/AKt/mTOR signaling and their role in the development of cancers. Additionally, we discussed the potential challenges and corresponding prediction biomarkers of response and resistance for PI3K/Akt/m- TOR inhibitor development. The article focuses on the most current breakthroughs in using the PI3K/Akt/mTOR pathway to target certain molecules.

Sennoside A induces autophagic death of prostate cancer via inactivation of PI3K/AKT/mTOR axis

Prostate cancer (PC) is the most common malignancy in male reproductive system. Sennoside A (SA) is an anthraquinone active ingredient extracted from Rheum officinale Baill., which exerts anti-tumor activity on different tumors. In the present study, the toxicity of SA on PC3 and DU 145 cells was detected via CCK-8. The effects of SA on growth, apoptosis, and autophagy were determined through CCK-8, Hoechst stain, flow cytometry, western blot, and immunofluorescence examinations. An in vivo experiment was performed in xenografted mice with intraperitoneal introduction of 10 mg/kg SA and validated via TUNEL, immunohistochemistry and western blot. The results showed that SA inhibited the cell viability with a IC50 value of 52.36 and 67.48 µM in DU 145 and PC3 cells respectively, and enhanced the apoptosis of PC3 and DU 145 cells. Additionally, SA elevated the relative LC3B expression, and the relative protein expression of LC3II/LC3I and Beclin-1, but diminished the P62 protein expression. The relative protein level of p-PI3K/PI3K, p-AKT/AKT and p-mTOR/mTOR was reduced with SA treatment, which was verified by the 740 Y-P application. The 740 Y-P treatments also restored the SA-induced the cell viability, apoptosis rate and relative LC3B expression. Meanwhile, SA inhibited the growth of PC cell and the relative protein level of PI3K/AKT/mTOR axis in vivo. Taken together, SA regulated the proliferation, apoptosis and autophagy via inactivating the PI3K/AKT/mTOR axis in PC.

Exploring the role of PI3K/AKT/mTOR inhibitors in hormone-related cancers: A focus on breast and prostate cancer

Breast cancer (BC) and prostate cancer (PC) are at the top of the list when it comes to the most common types of cancers worldwide. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is important, in that it strongly influences the development and progression of these tumors. Previous studies have emphasized the key role of inhibitors of the PIK3/AKT/mTOR signaling pathway in the treatment of BC and PC, and it remains to be a crucial method of treatment. In this review, the inhibitors of these signaling pathways are compared, as well as their effectiveness in therapy and potential as therapeutic agents. The use of these inhibitors as polytherapy is evaluated, especially with the use of hormonal therapy, which has shown promising results.

A Rare Pathological Phenotype of Endometrioid Serous and Clear-Cell Ovarian Cancer with PIK3CA Mutations in Relation to The Excellent Response of Alpelisib

Patients with metastatic ovarian cancer who develop resistance to standard therapy with or without platinum need to search for other therapeutic choices. Therefore, identifying genetic alterations and selecting an approach to treatment using precision medicine techniques are important. In a patient diagnosed with mixed-type ovarian cancer after surgery, adjuvant therapy was applied with a combination of carboplatin and taxane, but the disease recurred. Upon evaluation of the patient as having platinum-sensitive epithelial ovarian cancer (EOC), combination therapy with bevacizumab was initially successful. However, disease progression was again observed, and molecular analysis revealed the presence of an E545K mutation in the PIK3CA gene; therefore, a selective PI3K inhibitor, alpelisib, was used as a treatment under the compassionate-use protocol. The patient's complications improved after receiving the alpelisib medication. The patient has been in complete remission for over two years. This case serves as a rare example that confirms the utility of alpelisib in managing mixed-type ovarian cancer.

Improved efficacy of quizartinib in combination therapy with PI3K inhibition in primary FLT3-ITD AML cells

Acute myeloid leukemia is a heterogeneous hematopoietic malignancy, characterized by uncontrolled clonal proliferation of abnormal myeloid progenitor cells, with poor outcomes. The internal tandem duplication (ITD) mutation of the Fms-like receptor tyrosine kinase 3 (FLT3) (FLT3-ITD) represents the most common genetic alteration in AML, detected in approximately 30% of AML patients, and is associated with high leukemic burden and poor prognosis. Therefore, this kinase has been regarded as an attractive druggable target for the treatment of FLT3-ITD AML, and selective small molecule inhibitors, such as quizartinib, have been identified and trialled. However, clinical outcomes have been disappointing so far due to poor remission rates, also because of acquired resistance. A strategy to overcome resistance is to combine FLT3 inhibitors with other targeted therapies. In this study, we investigated the preclinical efficacy of the combination of quizartinib with the pan PI3K inhibitor BAY-806946 in FLT3-ITD cell lines and primary cells from AML patients. We show here that BAY-806946 enhanced quizartinib cytotoxicity and, most importantly, that this combination increases the ability of quizartinib to kill CD34+ CD38-leukemia stem cells, whilst sparing normal hematopoietic stem cells. Because constitutively active FLT3 receptor tyrosine kinase is known to boost aberrant PI3K signaling, the increased sensitivity of primary cells to the above combination can be the mechanistic results of the disruption of signaling by vertical inhibition.

Metastatic Castration-Resistant Prostate Cancer: Insights on Current Therapy and Promising Experimental Drugs

The therapeutic landscape of metastatic hormone sensitive and metastatic castration-resistant prostate cancer (mCRPC) is rapidly changing. We reviewed the current treatment options for mCRPC, with insights on new available therapeutic strategies. Chemotherapy with docetaxel or cabazitaxel (for patients progressing on docetaxel), as well as treatment with androgen receptor axis targeted therapies, and Radium-223 are well-established treatment options for patients with mCRPC. The advent of theragnostic in prostate cancer established Lutetium-177 (177Lu)-PSMA-617 as a new standard of care for PSMA-positive mCRPC previously treated with ARAT and taxane-based chemotherapy. Olaparib, a poly-ADP-ribose polymerase (PARP) inhibitor, is approved for selected patients with mCRPC progressed on ARATs and in combination with abiraterone acetate as first-line treatment for mCRPC. Immunotherapy showed limited efficacy in unselected patients with mCRPC and novel immunotherapy strategies need to be explored. The search for biomarkers is a growing field of interest in mCRPC, and predictive biomarkers are needed to support the choice of treatment and the development of tailored strategies.

Regulation of Chondrocyte Differentiation by miR-455-3p Secreted by Bone Marrow Stem Cells through Phosphatase and Tensin Homolog Deleted on Chromosome Ten/Phosphoinositide 3-Kinase-Protein Kinase B

The effects of the regulation of phosphatase and tensin homolog deleted on chromosome ten (PTEN) by microribonucleic acid- (miR-) 455-3p on bone marrow stem cells' (BMSCs') chondrogenic development were examined based on the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signal pathway. The alterations in miR-455-3p and PTEN were identified using osteoarthritis (OA) and healthy chondrocytes. Rats raised on the SD diet had their BMSCs isolated for chondrocyte-induced differentiation (blank group), transfected miR-455-3p mimic (mimic group), and inhibitor (inhibitor group). Besides, cell proliferation, alizarin red mineralization staining, and the activity of alkaline phosphatase (ALP) were detected. Real-time fluorescent quantitation polymerase chain reaction (PCR) and Western blot were utilized to detect Runx2, OPN, OSX, COL2A1 mRNA, and the difference between PI3K and AKT. Dual-luciferase reporter (DLR) genes were selected to analyze the target relationship of miR-455-3p to PTEN. It was demonstrated that miR-455-3p in OA was downregulated, while PTEN was upregulated (P < 0.05) in comparison to healthy chondrocytes (P < 0.05). Versus those in the blank group, alizarin red mineralization staining and the activity of ALP increased; RUNX, OPN, OSX, COL2A1 mRNA, p-PI3K, and p-AKT were elevated in the mimic group (P < 0.05). Versus those in the blank and mimic groups, alizarin red mineralization staining and the activity of ALP reduced; RUNX, OPN, OSX, COL2A1 mRNA, p-PI3K, and p-AKT were downregulated in the inhibitor group (P < 0.05). miR-455-3p could target PTEN to inhibit its expression, thus activating the PI3K/AKT signal pathway and promoting BMSCs chondrocyte-induced differentiation. The research results provided reference for the occurrence of OA and the study on therapeutic target.

Design, synthesis and molecular docking of novel substituted azepines as inhibitors of PI3K/Akt/TSC2/mTOR signaling pathway in colorectal carcinoma

A series of novel substituted azepines (2-7) was synthesized using both traditional and ultrasonic techniques. The efficiency of the reaction rate and yield was improved by sonication technique. We identified the newly synthesized compounds based on their melting points, elemental analyses, and spectral data. Human cancers are regulated mainly by the phosphatidylinositol 3-kinase/protein kinases B (PI3K/Akt) pathway, and its abnormal activation is linked to carcinogenesis, and angiogenesis. Using in-silico studies, we evaluated the ability of all the novel substituted diazepines and oxazepines to prevent cancer growth and metastasis by targeting the PI3K/Akt signaling pathway. Based on our findings, compounds 4a and 7a were chosen for in-vitro testing as they ranked via molecular docking the highest binding energies of -10.9, -10.3, -10.6, and -10.4 kcal/mol respectively. Compounds 4a and 7a displayed significant cytotoxicity on Caco-2 colorectal cancer cells with IC₅₀ values of 8.445 ± 2.26 and 33.04 ± 2.06 μM, respectively. Additionally, they considerably suppressed the PI3K/Akt proteins and generated reactive oxygen species (ROS), which increased p53 and Bax, decreased Bcl-₂ levels, and arrested the cell cycle at sub-G0/G1 phase. We also observed a remarkable overexpression of the Tuberous Sclerosis Complex 2 (TSC2) gene, an inhibitor of the mammalian target of rapamycin (mTOR). These results showed that compounds 4a and 7a obeyed Lipinski's rule of five and might be potential cancer treatment scaffolds by preventing metastasis and proliferation via blocking the PI3K/Akt/TSC2/m-TOR signaling pathway. This supports our hypothesis that diazepine 4a and oxazepine 7a are promising drug candidates for colorectal cancer.

Cincumol prevents malignant phenotype of colorectal cancer cell line HCT116 via inhibiting PI3K/AKT signaling in vitro

PURPOSE

Colorectal cancer (CRC) is a common human cancer along with higher incidence and mortality, and this study aimed to identify the effect of cincumol on CRC and its potential mechanisms.

METHODS

CRC cell line HCT116 was used as the material. Cell proliferation was evaluated by CCK-8 assay, and cell migration was detected by scratch test and Transwell assay. TUNEL staining assay was used to evaluate cell apoptosis. The expression of target genes was detected by qualitative real-time polymerase chain reaction and western blot assays.

RESULTS

Cincumol significantly reduced the proliferative and migratory rate and enhanced apoptotic rate of HCT116 cells. Meanwhile, the elevated levels of RBUsuh, Nicd and Tace was also observed in cincumol-treated HCT116 cells. Moreover, our findings revealed that additional cincumol inhibited the expression of p-PI3K and p-AKT, suggesting the inhibition of PI3K/AKT signaling might be involved in the protective role of cincumol on the malignant phenotypes of CRC cells in vitro.

CONCLUSIONS

Cincumol inhibited the malignant phenotypes of CRC cells in vitro through inactivating PI3K/AKT signaling, suggesting that cincumol might be a potential anti-CRC agent.

Molecular Aspects and Therapeutic Implications of Herbal Compounds Targeting Different Types of Cancer

Due to genetic changes in DNA (deoxyribonucleic acid) sequences, cancer continues to be the second most prevalent cause of death. The traditional target-directed approach, which is confronted with the importance of target function in healthy cells, is one of the most significant challenges in anticancer research. Another problem with cancer cells is that they experience various mutations, changes in gene duplication, and chromosomal abnormalities, all of which have a direct influence on the potency of anticancer drugs at different developmental stages. All of these factors combine to make cancer medication development difficult, with low clinical licensure success rates when compared to other therapy categories. The current review focuses on the pathophysiology and molecular aspects of common cancer types. Currently, the available chemotherapeutic drugs, also known as combination chemotherapy, are associated with numerous adverse effects, resulting in the search for herbal-based alternatives that attenuate resistance due to cancer therapy and exert chemo-protective actions. To provide new insights, this review updated the list of key compounds that may enhance the efficacy of cancer treatment.

Advancements in Oncoproteomics Technologies: Treading toward Translation into Clinical Practice

Proteomics continues to forge significant strides in the discovery of essential biological processes, uncovering valuable information on the identity, global protein abundance, protein modifications, proteoform levels, and signal transduction pathways. Cancer is a complicated and heterogeneous disease, and the onset and progression involve multiple dysregulated proteoforms and their downstream signaling pathways. These are modulated by various factors such as molecular, genetic, tissue, cellular, ethnic/racial, socioeconomic status, environmental, and demographic differences that vary with time. The knowledge of cancer has improved the treatment and clinical management; however, the survival rates have not increased significantly, and cancer remains a major cause of mortality. Oncoproteomics studies help to develop and validate proteomics technologies for routine application in clinical laboratories for (1) diagnostic and prognostic categorization of cancer, (2) real-time monitoring of treatment, (3) assessing drug efficacy and toxicity, (4) therapeutic modulations based on the changes with prognosis and drug resistance, and (5) personalized medication. Investigation of tumor-specific proteomic profiles in conjunction with healthy controls provides crucial information in mechanistic studies on tumorigenesis, metastasis, and drug resistance. This review provides an overview of proteomics technologies that assist the discovery of novel drug targets, biomarkers for early detection, surveillance, prognosis, drug monitoring, and tailoring therapy to the cancer patient. The information gained from such technologies has drastically improved cancer research. We further provide exemplars from recent oncoproteomics applications in the discovery of biomarkers in various cancers, drug discovery, and clinical treatment. Overall, the future of oncoproteomics holds enormous potential for translating technologies from the bench to the bedside.

LncRNA RHPN1-AS1 inhibition induces autophagy and apoptosis in prostate cancer cells via the miR-7-5p/EGFR/PI3K/AKT/mTOR signaling pathway

LncRNA RHPN1-AS1 (RHPN1-AS1) has been confirmed to promote tumor progression in multiple cancers and is upregulated in prostate cancer (PCa), but whether it has an effect on PCa progression remains unclear. In this study, we found that PCa patients with high RHPN1-AS1 expression had a shorter survival time, and RHPN1-AS1 was significantly upregulated in PCa tissues and cells. Based on informatics analysis we predicted that miR-7-5p binds to 3'UTR of RHPN1-AS1 and epidermal growth factor receptor (EGFR) and verified it by luciferase reporter gene assay. Subsequently, we transfected PCa cells with RHPN1-AS1 overexpression vector (RHPN1-AS1), knockdown plasmids (sh-RHPN1-AS1) and/or miR-7-5p mimics or inhibitor and/or overexpression vector (EGFR) or small interfering RNA of EGFR (si-EGFR) or its control, and found that overexpression of RHPN1-AS1 inhibited miR-7-5p expression and promoted EGFR expression, silencing RHPN1-AS1 inhibited proliferation and invasion, and induced G2/M arrest, apoptosis and autophagy in PCa cells. 3MA (an inhibitor of autophagy)-mediated autophagy inhibition attenuated RHPN1-AS1 inhibition-induced apoptosis. Overexpression miR-7-5p or silencing EGFR promoted LC3-I to LC3-II conversion, enhanced autophagy activity, induced cleaved-caspase-3 expression and apoptosis in PCa cells. Furthermore, overexpression of RHPN1-AS1 promoted phosphorylation of phosphatidylinositol 3-kinase (PI3K), AKT and mTOR, inhibited LC3-I to LC3-II conversion and reduced apoptosis in PCa cells, while GSK2126458 (an inhibitor of PI3K) reversed the effect of RHPN1-AS1 on PCa cells. In summary, RHPN1-AS1 acted as a ceRNA of miR-7-5p to upregulate EGFR expression, silencing RHPN1-AS1 suppressed PCa tumor progression by inducing autophagy and apoptosis in PCa cells through the miR-7-5p/EGFR/PI3K/AKT/mTOR pathway.

DNA Methyltransferase Inhibitor 5-AZA-DC Regulates TGFβ1-Mediated Alteration of Neuroglial Cell Functions after Oxidative Stress

5-AZA-DC is an efficient methylation inhibitor that inhibits methylation of target DNA. In this study, we explored the effects of 5-AZA-DC on the regulation of TGFβ1 on target genes in neuroglial cell, as well as neuroglial cell functions under oxidative stress. The oxidative stress was constructed by editing CRISPR/Cas9 for knock out Ang-1 and ApoE4 genes. Cells were subjected to TGFβ1OE (or shTGFβ1) transfection and/or 5-AZA-DC intervention. Results showed that under oxidative stress, both TGFβ1OE and shTGFβ1 transfection raised DNMT1, but reduced TGFβ1, PTEN, and TSC2 expressions in neuroglial cells. TGFβ1 directly bind to the promoter of PTEN gene. 5-AZA-DC intervention lowered DNMT1 and raised TGFβ1 expression, as well as promoted the binding between TGFβ1 and promoter of PTEN. TGFβ1OE caused a significant increase in the DNA demethylation level of PTEN promoter, while 5-AZA-DC intervention reduced the DNA demethylation level of PTEN promoter. Under oxidative stress, TGFβ1OE (or shTGFβ1) transfection inhibited neuroglial cell proliferation, migration, and invasion, promoted cell apoptosis. 5-AZA-DC intervention alleviated TGFβ1OE (or shTGFβ1) transfection caused neuroglial cell proliferation, migration, and invasion inhibition, as well as cell apoptosis. To conclude, these results suggest that 5-AZA-DC can be used as a potential drug for epigenetic therapy on oxidative stress damage in neuroglial cells. The findings of this research provide theoretical basis and research ideas for methylation drug intervention and TGFβ1 gene as a possible precise target of glial oxidative stress diagnosis and treatment.

Curcumin against gastrointestinal cancer: A review of the pharmacological mechanisms underlying its antitumor activity

Gastrointestinal cancer (GIC) poses a serious threat to human health globally. Curcumin (CUR), a hydrophobic polyphenol extracted from the rhizome of Curcuma longa, has shown reliable anticancer function and low toxicity, thereby offering broad research prospects. Numerous studies have demonstrated the pharmacological mechanisms underlying the effectiveness of CUR against GIC, including the induction of apoptosis and autophagy, arrest of the cell cycle, inhibition of the epithelial–mesenchymal transition (EMT) processes, inhibition of cell invasion and migration, regulation of multiple signaling pathways, sensitization to chemotherapy and reversal of resistance to such treatments, and regulation of the tumor survival environment. It has been confirmed that CUR exerts its antitumor effects on GIC through these mechanisms in vitro and in vivo. Moreover, treatment with CUR is safe and tolerable. Newly discovered types of regulated cell death (RCD), such as pyroptosis, necroptosis, and ferroptosis, may provide a new direction for research on the efficacy of CUR against GIC. In this review, we discuss the recently found pharmacological mechanisms underlying the effects of CUR against GIC (gastric and colorectal cancers). The objective is to provide a reference for further research on treatments against GIC.

PTEN-PI3K pathway alterations in advanced prostate cancer and clinical implications

BACKGROUND

Despite significant advances in molecular characterization and therapeutic targeting of advanced prostate cancer, it remains the second most common cause of cancer death in men in the United States. The PI3K (Phosphatidylinositol 3-kinase)/AKT (AKT serine/threonine kinase)/mTOR (mammalian target of rapamycin) signaling pathway is commonly altered in prostate cancer, most frequently through loss of the PTEN (Phosphatase and Tensin Homolog) tumor suppressor, and is critical for cancer cell proliferation, migration, and survival.

METHODS

This study summarizes signaling through the PTEN/PI3K pathway, alterations in pathway components commonly seen in advanced prostate cancer, and results of clinical trials of pathway inhibitors reported to date with a focus on more recently reported studies. It also reviews rationale for combination approaches currently under study, including with taxanes, immune checkpoint inhibitors and poly (ADP-ribose) polymerase inhibitors, and discusses future directions in biomarker testing and therapeutic targeting of this pathway.

RESULTS

Clinical trials studying pharmacologic inhibitors of PI3K, AKT or mTOR kinases have demonstrated modest activity of specific agents, with several trials of pathway inhibitors currently in progress. A key challenge is the importance of PI3K/AKT/mTOR signaling in noncancerous tissues, leading to predictable but often severe toxicities at therapeutic doses.

RESULTS

Further advances in selective pharmacologic inhibition of the PI3K/AKT/mTOR pathway in tumors, development of rational combinations, and appropriate biomarker selection to identify the appropriate tumor- and patient-specific vulnerabilities will be required to optimize clinical benefit from therapeutic targeting of this pathway.

Synergistic effect of obeticholic acid and fasting-mimicking on proliferative, migration, and survival signaling in prostate cancer

The systemic and resistant nature of the androgen-independent stage of prostate cancers makes it largely incurable even after intensive multimodal therapy. Apoptosis and epithelial-mesenchymal transition (EMT) are two fundamental events that are deeply linked to carcinogenesis. Hence, it is necessary to find a new combination of several therapies targeting apoptosis and EMT without causing side effects. Several recent studies have indicated that the Farnesoid X receptor is extensively associated with human tumorigenesis. The FXR agonist obeticholic acid (INT 747) has preliminarily exhibited a tumor suppressor potential. In this present study, we assess the potential synergism of FXR activation under nutrient deprivation in prostate cancer cell lines to investigate whether FXR activation enhances starvation-induced apoptosis in PC3 cells. In this study, PC-3 treatment with INT 747 significantly repressed cell proliferation and clonogenic potential. In addition, it significantly induced apoptosis of PC-3 cells and decreased their cancerogenic potential, as evaluated by annexin v apoptosis and transwell migration assay, respectively. The decreased expression of pro-caspase 3 by western blot analysis further confirmed INT 747-induced apoptosis. Furthermore, the fasting-mimicking diet (FMD) potentiated the antiproliferative, pro-apoptotic, and antimetastatic effects of INT 747. Mechanistically, these effects were mediated through the downregulation of cyclin D1 and upregulation of PTEN. In conclusion, INT 747 alone markedly decreases, and when combined with FMD abrogates the growth and migration of PC-3 cells.

Cinnamomum zeylanicum Extract and its Bioactive Component Cinnamaldehyde Show Anti-Tumor Effects via Inhibition of Multiple Cellular Pathways

Cinnamomum zeylanicum is a tropical plant with traditional medicinal significance that possesses antimicrobial, antifungal, anti-parasitic, and anti-tumor properties. Here, we have elucidated the anti-tumor effects of Cinnamomum zeylanicum extract (CZE) and its bioactive compound cinnamaldehyde (CIN) on oral cancer and elucidated underlying molecular mechanisms. Anti-tumor activities of CZE and CIN were demonstrated by various in vitro experiments on oral cancer cells (SCC-4, SCC-9, SCC-25). The cell proliferation, growth, cell cycle arrest, apoptosis, and autophagy were analyzed by MTT, clonogenic assay, propidium iodide, annexin-V-PI, DAPI, and acridine orange staining, respectively. The binding affinity of CIN towards dihydrofolate reductase and p38-MAP kinase alpha was analyzed by molecular docking. Western blot assay was performed to assess the alteration in the expression of various proteins. CZE and CIN treatment significantly inhibited the growth and proliferation of oral cancer cells in a dose-dependent manner. These treatments further induced apoptosis, cell cycle arrest, and autophagy. CZE and CIN inhibited the invasion and cytoplasmic translocation of NF-κB in these cell lines. CIN showed a high affinity to MAP kinase P38 alpha and dihydrofolate reductase with binding affinities of −6.8 and −5.9 kcal/mol, respectively. The cancer cells showed a decreased expression of various PI3k-AKT-mTOR pathways related to VEGF, COX-2, Bcl-2, NF-κB, and proteins post-treatment.

Phase Ib/II Study of Enzalutamide with Samotolisib (LY3023414) or Placebo in Patients with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

To report efficacy and safety of samotolisib (LY3023414; PI3K/mTOR dual kinase and DNA-dependent protein kinase inhibitor) plus enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) following cancer progression on abiraterone.

PATIENTS AND METHODS

In this double-blind, placebo-controlled phase Ib/II study (NCT02407054), following a lead-in segment for evaluating safety and pharmacokinetics of samotolisib and enzalutamide combination, patients with advanced castration-resistant prostate cancer with progression on prior abiraterone were randomized to receive enzalutamide (160 mg daily)/samotolisib (200 mg twice daily) or placebo. Primary endpoint was progression-free survival (PFS) assessed by Prostate Cancer Clinical Trials Working Group criteria (PCWG2). Secondary and exploratory endpoints included radiographic PFS (rPFS) and biomarkers, respectively. Log-rank tests assessed treatment group differences.

RESULTS

Overall, 13 and 129 patients were enrolled in phase Ib and II, respectively. Dose-limiting toxicity was not reported in patients during phase Ib and mean samotolisib exposures remained in the targeted range despite a 35% decrease when administered with enzalutamide. In phase II, median PCWG2-PFS and rPFS was significantly longer in the samotolisib/enzalutamide versus placebo/enzalutamide arm (3.8 vs. 2.8 months; P = 0.003 and 10.2 vs. 5.5 months; P = 0.03), respectively. Patients without androgen receptor splice variant 7 showed a significant and clinically meaningful rPFS benefit in the samotolisib/enzalutamide versus placebo/enzalutamide arm (13.2 months vs. 5.3 months; P = 0.03).

CONCLUSIONS

Samotolisib/enzalutamide has tolerable side effects and significantly improved PFS in patients with mCRPC with cancer progression on abiraterone, and this may be enriched in patients with PTEN intact and no androgen receptor splice variant 7.

The Integration of Metabolomics with Other Omics: Insights into Understanding Prostate Cancer

Our understanding of prostate cancer (PCa) has shifted from solely caused by a few genetic aberrations to a combination of complex biochemical dysregulations with the prostate metabolome at its core. The role of metabolomics in analyzing the pathophysiology of PCa is indispensable. However, to fully elucidate real-time complex dysregulation in prostate cells, an integrated approach based on metabolomics and other omics is warranted. Individually, genomics, transcriptomics, and proteomics are robust, but they are not enough to achieve a holistic view of PCa tumorigenesis. This review is the first of its kind to focus solely on the integration of metabolomics with multi-omic platforms in PCa research, including a detailed emphasis on the metabolomic profile of PCa. The authors intend to provide researchers in the field with a comprehensive knowledge base in PCa metabolomics and offer perspectives on overcoming limitations of the tool to guide future point-of-care applications.

ZDQ-0620, a Novel Phosphatidylinositol 3-Kinase Inhibitor, Inhibits Colorectal Carcinoma Cell Proliferation and Suppresses Angiogenesis by Attenuating PI3K/AKT/mTOR Pathway

The PI3K/AKT pathway plays a central role in human cancers, aberrant activation of this pathway is associated with tumorigenesis, cancer progression and angiogenesis. Based on the importance of the PI3K/AKT pathway in malignancies, we developed a 4-aminoquinazoline derivative, ZDQ-0620, initially envisioned as a novel pan-PI3K inhibitor. This study aimed to evaluate the potential target of ZDQ-0620 and its anticancer effect in human colorectal carcinoma (CRC). PI3K-kinase activity test showed IC50 of ZDQ-0620 against PI3Ka was 0.5 nM; molecular docking, CETSA assay and western blotting was further performed to predict ZDQ-0620 was a PI3K/AKT pathway inhibitor by targeting PI3K. To identify the effect of ZDQ-0620 on CRC cells, Sulforhodamine B (SRB) assay, flow cytometry, and Cell morphology analysis were conducted. The results showed that ZDQ-0620 inhibited the proliferation, migration and invasion of CRC cells, induced apoptosis through G0/G1 cell cycle arrest and mitochondrial pathway. Additionally, ZDQ-0620 inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). In vivo, neovascularization of rat aortic ring and chick chorioallantoic membrane (CAM) induced by VEGF was diminished when treated with ZDQ-0620. These results indicate that ZDQ-0620 induce apoptosis and anti-angiogenesis via inhibits the PI3K/AKT pathway. We suggest that the great potential of ZDQ-0620 as an effective treatment candidate against CRC.

Targeting autophagy in prostate cancer: preclinical and clinical evidence for therapeutic response

Prostate cancer is a leading cause of death worldwide and new estimates revealed prostate cancer as the leading cause of death in men in 2021. Therefore, new strategies are pertinent in the treatment of this malignant disease. Macroautophagy/autophagy is a “self-degradation” mechanism capable of facilitating the turnover of long-lived and toxic macromolecules and organelles. Recently, attention has been drawn towards the role of autophagy in cancer and how its modulation provides effective cancer therapy. In the present review, we provide a mechanistic discussion of autophagy in prostate cancer. Autophagy can promote/inhibit proliferation and survival of prostate cancer cells. Besides, metastasis of prostate cancer cells is affected (via induction and inhibition) by autophagy. Autophagy can affect the response of prostate cancer cells to therapy such as chemotherapy and radiotherapy, given the close association between autophagy and apoptosis. Increasing evidence has demonstrated that upstream mediators such as AMPK, non-coding RNAs, KLF5, MTOR and others regulate autophagy in prostate cancer. Anti-tumor compounds, for instance phytochemicals, dually inhibit or induce autophagy in prostate cancer therapy. For improving prostate cancer therapy, nanotherapeutics such as chitosan nanoparticles have been developed. With respect to the context-dependent role of autophagy in prostate cancer, genetic tools such as siRNA and CRISPR-Cas9 can be utilized for targeting autophagic genes. Finally, these findings can be translated into preclinical and clinical studies to improve survival and prognosis of prostate cancer patients.

• Prostate cancer is among the leading causes of death in men where targeting autophagy is of importance in treatment;

• Autophagy governs proliferation and metastasis capacity of prostate cancer cells;

• Autophagy modulation is of interest in improving the therapeutic response of prostate cancer cells;

• Molecular pathways, especially involving non-coding RNAs, regulate autophagy in prostate cancer;

• Autophagy possesses both diagnostic and prognostic roles in prostate cancer, with promises for clinical application.

CircNR3C1 Alleviates Gastric Cancer Development by Inactivating AKT/mTOR

Differential level and regulatory effect of circNR3C1 in gastric cancer (GC) were determined. The differential levels of circNR3C1 in clinical samples of GC were determined. The association of circNR3C1 level with pathological indicators of GC was analyzed. After intervening circNR3C1 levels in gastric cancer cells, proliferative and migratory changes were investigated. Furthermore, we measured AKT and mTOR protein levels in GC cells intervened by circNR3C1. Finally, the role of AKT/mTOR in GC cell phenotypes regulated by circNR3C1 was explored. circNR3C1 was markedly lowly expressed in GC cells and tissues. A low level of circNR3C1 predicted high incidences of lymphatic or distant metastasis of GC. Knockdown of circNR3C1 enhanced proliferation and migration abilities in BGC-823 cells, whereas overexpression of circNR3C1 yielded the opposite results in AGS cells. circNR3C1 downregulated mTOR and AKT in GC cells. In addition, induction of the AKT activator could reverse the attenuated proliferative and migratory potentials in GC cells overexpressing circNR3C1. On the contrary, induction of the AKT inhibitor reversed the stimulated malignant phenotypes of GC with circNR3C1 knockdown. circNR3C1 inhibits GC to proliferate and migrate by inactivating the AKT/mTOR signaling. It is also closely linked to GC metastasis.

rAAV-delivered PTEN therapeutics for prostate cancer

Effective treatments for prostate cancer (PCa) require further development, and previous studies have reported that PTEN and its downstream target CDKN1B are significantly downregulated in PCa cells compared with normal cells. Therefore, modulation of PTEN and CDKN1B expression might be a promising therapeutic approach for PCa treatment. Expression of PTEN and CDKN1B was verified in specimens from PCa patients and transgenic adenocarcinoma mouse prostate (TRAMP) mice. The effect of PTEN on PCa cell migration, apoptosis, and the cell cycle was analyzed in vitro using a wound-healing assay and flow cytometry. We assessed the ability of intraprostatic and intratumoral injections of recombinant adeno-associated virus (rAAV) 9 expressing Pten or Cdkn1b into TRAMP mice and a subcutaneous tumor xenograft mouse model, respectively, to inhibit PCa progression. PTEN and CDKN1B were significantly downregulated in human and mouse PCa samples, and CDKN1B expression correlated positively with PTEN expression. PTEN overexpression significantly inhibited cell migration and cell-cycle progression and promoted apoptosis in PCa cells by decreasing Ccnd1 expression and increasing that of Cdkn1b. Importantly, treatment with the rAAV9.Pten or rAAV9.Cdkn1b extended the lifespan of TRAMP mice and inhibited the growth rate of tumor xenografts by regulating downstream gene expression. Moreover, neoplasia in treated prostates was significantly diminished compared with that in control prostates, and apoptosis was markedly observed in xenografts treated with Pten or Cdkn1b. These data indicate that rAAV-based PTEN/CDKN1B delivery is promising for the development of novel therapeutics for PCa.

Gene Expression Profiling and Protein Analysis Reveal Suppression of the C-Myc Oncogene and Inhibition JAK/STAT and PI3K/AKT/mTOR Signaling by Thymoquinone in Acute Myeloid Leukemia Cells

Overexpression of c-Myc plays an essential role in leukemogenesis and drug resistance, making c-Myc an attractive target for cancer therapy. However, targeting c-Myc directly is impossible, and c-Myc upstream regulator pathways could be targeted instead. This study investigated the effects of thymoquinone (TQ), a bioactive constituent in Nigella sativa, on the activation of upstream regulators of c-Myc: the JAK/STAT and PI3K/AKT/mTOR pathways in HL60 leukemia cells. Next-generation sequencing (NGS) was performed for gene expression profiling after TQ treatment. The expression of c-Myc and genes involved in JAK/STAT and PI3K/AKT/mTOR were validated by quantitative reverse transcription PCR (RT-qPCR). In addition, Jess assay analysis was performed to determine TQ’s effects on JAK/STAT and PI3K/AKT signaling and c-Myc protein expression. The results showed 114 significant differentially expressed genes after TQ treatment (p < 0.002). DAVID analysis revealed that most of these genes’ effect was on apoptosis and proliferation. There was downregulation of c-Myc, PI3K, AKT, mTOR, JAK2, STAT3, STAT5a, and STAT5b. Protein analysis showed that TQ also inhibited JAK/STAT and PI3K/AKT signaling, resulting in inhibition of c-Myc protein expression. In conclusion, the findings suggest that TQ potentially inhibits proliferation and induces apoptosis in HL60 leukemia cells by downregulation of c-Myc expression through inhibition of the JAK/STAT and PI3K/AKT signaling pathways.

Exosomes in Pathogenesis, Diagnosis, and Treatment of Hepatocellular Carcinoma

Exosomes are extracellular vesicles with a diameter of 30-150 nm that are released by most types of cells and have been confirmed to be involved in many physical and pathological processes, especially in cell to cell communication. Compared with other vesicles, exosomes have a unique double-layer saclike structure that allows them to be present stably in various body fluids, including blood, cerebrospinal fluid, urine, saliva, and serous cavity effusion. The cargoes of exosomes reflect the characteristics of host cells. Due to the nature of hepatocellular carcinoma (HCC) cells, heterogeneity in the bioactive substances usually exist in exosomes. In addition, exosomes can efficiently deliver cargoes to the target cells to exert pathological functions, playing important role in tumor occurrence, development, metastasis, immune regulation, and drug resistance. Previous studies have been shown that exosomes have wide applications in diagnosis and treatment of HCC. In this review, we discuss these recent findings and highlight the significant roles of exosomes in HCC, focusing on the effect and underlying mechanisms of exosomes to regulate HCC progression and the potential clinical value of exosomes as biomarkers and therapeutic targets.

Protein tyrosine phosphatase receptor type Z1 inhibits the cisplatin resistance of ovarian cancer by regulating PI3K/AKT/mTOR signal pathway

Most patients with ovarian cancer (OC) get remission after undergoing cytoreductive surgery and platinum-based standard chemotherapy, but more than 50% of patients with advanced OC relapse within the first 5 years after treatment and develop resistance to standard chemotherapy. The production of medicinal properties is the main reason for the poor prognosis and high mortality of OC patients. Cisplatin (DDP) resistance is a major cause for poor prognosis of OC patients. PTPRZ1 can regulate the growth and apoptosis of ovarian cancer cells, while the molecular mechanism remains unknown. This study was designed to investigate the roles of PTPRZ1 in DDP-resistant OC cells and possible mechanism. PTPRZ1 expression in OC tissues and normal tissues was analyzed by GEPIA database and verified by Real-time Quantitative Reverse Transcription PCR (RT-PCR) assay. PTPRZ1 expression in normal ovarian cancer cells and DDP-resistant OC cells was also analyzed. Subsequently, RT-PCR, Western blot, MTT experiment and flow cytometry were used to assess the effects of PTPRZ1-PI3K/AKT/mTOR regulating axis on DDP resistance of OC. PTPRZ1 expression was abnormally low in OC tissues, and notably reduced in DDP-resistant OC cells. MTT experiment and flow cytometer indicated that overexpression of PTPRZ1 enhanced the DDP sensitivity of OC cells and promoted the cell apoptosis. Moreover, the results of our research showed that PTPRZ1 might exert its biological effects through blocking PI3K/AKT/mTOR pathway. PTPRZ1 overexpression inhibitied OC tumor growth and resistance to DDP in vivo. Overall, PTPRZ1 might suppress the DDP resistance of OC and induce the cytotoxicity by blocking PI3K/AKT/mTOR pathway.

Epicatechin gallate prevents the de novo synthesis of fatty acid and the migration of prostate cancer cells

Lipid metabolism disorder caused by the upregulation of lipogenic genes is a typical feature of prostate cancer. The synthesis of fatty acids is enhanced to accelerate the development of prostate cancer and is considered as a potential therapeutic target. Epicatechin gallate, an active compound of green tea, has been reported to modulate lipid metabolism. In this research, the potential role of epicatechin gallate in prostate cancer cells was evaluated. The results indicated that epicatechin gallate downregulates the expression of acetyl-CoA carboxylase, ATP citrate lyase, and fatty acid synthase in prostate cancer cells and prostate xenograft tissues, suggesting that epicatechin gallate can inhibit de novo fatty acid synthesis. Moreover, epicatechin gallate significantly restrains the migration rather than the viability of prostate cancer cells. PI3K/AKT/mTOR signaling pathway, which exhibits regulatory effect on lipogenesis, is also inhibited under epicatechin gallate treatment, while pretreatment with AKT activator SC79 or mTOR activator MHY1485 blocks the inhibitory effect of epicatechin gallate on the expression of lipogenic genes and the migration of prostate cancer cells. In conclusion, this study revealed that epicatechin gallate impairs the synthesis of fatty acids via inhibition PI3K/AKT/mTOR signaling pathway and then attenuates the migration of prostate cancer cells.

An RNA-Seq-Based Framework for Characterizing Canine Prostate Cancer and Prioritizing Clinically Relevant Biomarker Candidate Genes

Prostate cancer (PCa) in dogs is a highly malignant disease akin to its human counterpart. In contrast to the situation in humans, multi-gene approaches facilitating risk stratification of canine PCa are barely established. The aims of this study were the characterization of the transcriptional landscape of canine PCa and the identification of diagnostic, prognostic and/or therapeutic biomarkers through a multi-step screening approach. RNA-Sequencing of ten malignant tissues and fine-needle aspirations (FNA), and 14 nonmalignant tissues and FNAs was performed to find differentially expressed genes (DEGs) and deregulated pathways. The 4098 observed DEGs were involved in 49 pathways. These 49 pathways could be grouped into five superpathways summarizing the hallmarks of canine PCa: (i) inflammatory response and cytokines; (ii) regulation of the immune system and cell death; (iii) cell surface and PI3K signaling; (iv) cell cycle; and (v) phagosome and autophagy. Among the highly deregulated, moderately to strongly expressed DEGs that were members of one or more superpathways, 169 DEGs were listed in relevant databases and/or the literature and included members of the PCa pathway, oncogenes, prostate-specific genes, and druggable genes. These genes are novel and promising candidate diagnostic, prognostic and/or therapeutic canine PCa biomarkers.

Single-molecule studies reveal regulatory interactions between master kinases PDK1, AKT1, and PKC

Leukocyte migration is controlled by a leading-edge chemosensory pathway that generates the regulatory lipid phosphatidylinositol-3,4,5-trisphosphate (PIP₃), a growth signal, thereby driving leading-edge expansion up attractant gradients toward sites of infection, inflammation, or tissue damage. PIP₃ also serves as an important growth signal in growing cells and oncogenesis. The kinases PDK1, AKT1 or PKB, and PKCα are key components of a plasma-membrane-based PIP₃ and Ca²⁺ signaling circuit that regulates these processes. PDK1 and AKT1 are recruited to the membrane by PIP₃, whereas PKCα is recruited to the membrane by Ca²⁺. All three of these master kinases phosphoregulate an array of protein targets. For example, PDK1 activates AKT1, PKCα, and other AGC kinases by phosphorylation at key sites. PDK1 is believed to form PDK1-AKT1 and PDK1-PKCα heterodimers stabilized by a PDK1-interacting fragment (PIF) interaction between the PDK1 PIF pocket and the PIF motif of the AGC binding partner. Here, we present the first, to our knowledge, single-molecule studies of full-length PDK1 and AKT1 on target membrane surfaces, as well as their interaction with full-length PKCα. These studies directly detect membrane-bound PDK1-AKT1 and PDK1-PKCα heterodimers stabilized by PIF interactions formed at physiological ligand concentrations. PKCα exhibits eightfold higher PDK1 affinity than AKT1 and can competitively displace AKT1 from PDK1-AKT1 heterodimers. Ensemble activity measurements under matched conditions reveal that PDK1 activates AKT1 via a cis mechanism by phosphorylating an AKT1 molecule in the same PDK1-AKT1 heterodimer, whereas PKCα acts as a competitive inhibitor of this phosphoactivation reaction by displacing AKT1 from PDK1. Overall, the findings provide insights into the binding and regulatory interactions of the three master kinases on their target membrane and suggest that a recently described tumor suppressor activity of PKC isoforms may arise from its ability to downregulate PDK1-AKT1 phosphoactivation in the PIP₃-PDK1-AKT1-mTOR pathway linked to cell growth and oncogenesis.

Genetic comprehension of organophosphate flame retardants, an emerging threat to prostate cancer

In recent years, organophosphate ester flame retardants (OPFRs), which have been regarded as alternatives for brominated flame retardants (BFRs), have become widely used in building materials, textiles, and electric equipment. Elucidating the relationship between OPFRs and tumors holds great significance for the treatment and prevention of diseases. In this work, we found a new method for predicting the correlation between the interactive genes of OPFRs and tumors. Transcriptome profiles and OPFR information were obtained from The Cancer Genome Atlas and the Genotype-Tissue Expression, Comparative Toxicogenomics, and PharmMapper databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed that interactive genes were mainly enriched in prostate cancer, steroid metabolic process, and steroid hormone regulation. Furthermore, protein-protein interaction network analysis revealed 33 biological hub genes. The operating characteristic curves and survival analysis showed the role of key genes in predicting the prognosis of prostate cancer. Gene target prediction and gene set variation analysis proved that OPFRs and their metabolites exert potential effects on prostate cancer. Colony formation assay showed that the cells with AR, mTOR and DDIT3 knockdown could remarkably mitigate the cell proliferation ability in both PC-3 and LNCap cells. Transwell assay demonstrated that the silencing of AR, mTOR and DDIT3 could significantly inhibit the cell invasion capacity of prostate cells. Triphenyl phosphate (TPP) significantly increase the cell proliferation ability and promote cell invasion capacity. AR, mTOR and DDIT3 in the PC-3 and LNCap cells were significantly upregulated with 10-6 M TPP treated.

Role of PI3K-AKT-mTOR Pathway as a Pro-Survival Signaling and Resistance-Mediating Mechanism to Therapy of Prostate Cancer

Androgen deprivation therapy (ADT) and androgen receptor (AR)-targeted therapy are the gold standard options for treating prostate cancer (PCa). These are initially effective, as localized and the early stage of metastatic disease are androgen- and castration-sensitive. The tumor strongly relies on systemic/circulating androgens for activating AR signaling to stimulate growth and progression. However, after a certain point, the tumor will eventually develop a resistant stage, where ADT and AR antagonists are no longer effective. Mechanistically, it seems that the tumor becomes more aggressive through adaptive responses, relies more on alternative activated pathways, and is less dependent on AR signaling. This includes hyperactivation of PI3K-AKT-mTOR pathway, which is a central signal that regulates cell pro-survival/anti-apoptotic pathways, thus, compensating the blockade of AR signaling. The PI3K-AKT-mTOR pathway is well-documented for its crosstalk between genomic and non-genomic AR signaling, as well as other signaling cascades. Such a reciprocal feedback loop makes it more complicated to target individual factor/signaling for treating PCa. Here, we highlight the role of PI3K-AKT-mTOR signaling as a resistance mechanism for PCa therapy and illustrate the transition of prostate tumor from AR signaling-dependent to PI3K-AKT-mTOR pathway-dependent. Moreover, therapeutic strategies with inhibitors targeting the PI3K-AKT-mTOR signal used in clinic and ongoing clinical trials are discussed.

Mechanisms Involved in the Promoting Activity of Fibroblasts in HTLV-1-Mediated Lymphomagenesis: Insights into the Plasticity of Lymphomatous Cells

Among the mechanisms leading to progression to Adult T-cell Leukaemia/Lymphoma in Human T-cell Leukaemia Virus type 1 (HTLV-1)-infected subjects, the contribution of stromal components remains poorly understood. To dissect the role of fibroblasts in HTLV-1-mediated lymphomagenesis, transcriptome studies, cytofluorimetric and qRT-PCR analyses of surface and intracellular markers linked to plasticity and stemness in coculture, and in vivo experiments were performed. A transcriptomic comparison between a more lymphomagenic (C91/III) and the parental (C91/PL) cell line evidenced hyperactivation of the PI3K/Akt pathway, confirmed by phospho-ELISA and 2-DE and WB analyses. C91/III cells also showed higher expression of mesenchymal and stemness genes. Short-term coculture with human foreskin fibroblasts (HFF) induced these features in C91/PL cells, and significantly increased not only the cancer stem cells (CSCs)-supporting CD10+GPR77+ HFF subpopulation, but also the percentage of ALDH1bright C91/PL cells. A non-cytotoxic acetylsalicylic acid treatment decreased HFF-induced ALDH1bright C91/PL cells, downregulated mesenchymal and stemness genes in cocultured cells, and delayed lymphoma growth in immunosuppressed mice, thus hindering the supportive activity of HFF on CSCs. These data suggest that crosstalk with HFF significantly intensifies the aggressiveness and plasticity of C91/PL cells, leading to the enrichment in lymphoma-initiating cells. Additional research is needed to better characterize these preliminary findings.

Synergistic cytotoxicity of dual PI3K/mTOR and FLT3 inhibition in FLT3-ITD AML cells

Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy, characterized by a heterogeneous genetic landscape and complex clonal evolution, with poor outcomes. Mutation at the internal tandem duplication of FLT3 (FLT3-ITD) is one of the most common somatic alterations in AML, associated with high relapse rates and poor survival due to the constitutive activation of the FLT3 receptor tyrosine kinase and its downstream effectors, such as PI3K signaling. Thus, aberrantly activated FLT3-kinase is regarded as an attractive target for therapy for this AML subtype, and a number of small molecule inhibitors of this kinase have been identified, some of which are approved for clinical practice. Nevertheless, acquired resistance to these molecules is often observed, leading to severe clinical outcomes. Therapeutic strategies to tackle resistance include combining FLT3 inhibitors with other antileukemic agents. Here, we report on the preclinical activity of the combination of the FLT3 inhibitor quizartinib with the dual PI3K/mTOR inhibitor PF-04691502 in FLT3-ITD cells. Briefly, we show that the association of these two molecules displays synergistic cytotoxicity in vitro in FLT3-ITD AML cells, triggering 90% cell death at nanomolar concentrations after 48 h.

Primary cilia and lipid raft dynamics

Primary cilia, antenna-like structures of the plasma membrane, detect various extracellular cues and transduce signals into the cell to regulate a wide range of functions. Lipid rafts, plasma membrane microdomains enriched in cholesterol, sphingolipids and specific proteins, are also signalling hubs involved in a myriad of physiological functions. Although impairment of primary cilia and lipid rafts is associated with various diseases, the relationship between primary cilia and lipid rafts is poorly understood. Here, we review a newly discovered interaction between primary cilia and lipid raft dynamics that occurs during Akt signalling in adipogenesis. We also discuss the relationship between primary cilia and lipid raft-mediated Akt signalling in cancer biology. This review provides a novel perspective on primary cilia in the regulation of lipid raft dynamics.

Regulation of mRNA Translation by Hormone Receptors in Breast and Prostate Cancer

Simple Summary

The estrogen and androgen receptors (ER, AR) are key oncogenic drivers and therapeutic targets in breast and prostate cancer, respectively. These receptors bind to DNA and regulate gene expression but emerging evidence indicates that they also play important roles in controlling the process of mRNA translation, which dictates cellular protein production. Here, we review the mechanisms by which abnormal activities of ER and AR can dysregulate mRNA translation in breast and prostate cancer cells. Specifically, we explore how the intricate cellular signalling pathways that keep mRNA translation in check are perturbed by aberrant ER and AR signalling, which can lead to enhanced cancer cell growth. We also discuss the potential of targeting mRNA translation as a strategy to treat patients with breast and prostate cancer.

Abstract

Breast and prostate cancer are the second and third leading causes of death amongst all cancer types, respectively. Pathogenesis of these malignancies is characterised by dysregulation of sex hormone signalling pathways, mediated by the estrogen receptor-α (ER) in breast cancer and androgen receptor (AR) in prostate cancer. ER and AR are transcription factors whose aberrant function drives oncogenic transcriptional programs to promote cancer growth and progression. While ER/AR are known to stimulate cell growth and survival by modulating gene transcription, emerging findings indicate that their effects in neoplasia are also mediated by dysregulation of protein synthesis (i.e., mRNA translation). This suggests that ER/AR can coordinately perturb both transcriptional and translational programs, resulting in the establishment of proteomes that promote malignancy. In this review, we will discuss relatively understudied aspects of ER and AR activity in regulating protein synthesis as well as the potential of targeting mRNA translation in breast and prostate cancer.

Lemur Tyrosine Kinases and Prostate Cancer: A Literature Review

The members of the Lemur Tyrosine Kinases (LMTK1-3) subfamily constitute a group of three membrane-anchored kinases. They are known to influence a wide variety of key cellular events, often affecting cell proliferation and apoptosis. They have been discovered to be involved in cancer, in that they impact various signalling pathways that influence cell proliferation, migration, and invasiveness. Notably, in the context of genome-wide association studies, one member of the LMTK family has been identified as a candidate gene which could contribute to the development of prostate cancer. In this review, of published literature, we present evidence on the role of LMTKs in human prostate cancer and model systems, focusing on the complex network of interacting partners involved in signalling cascades that are frequently activated in prostate cancer malignancy. We speculate that the modulators of LMTK enzyme expression and activity would be of high clinical relevance for the design of innovative prostate cancer treatment.

Current updates on precision therapy for breast cancer associated brain metastasis: Emphasis on combination therapy

Cancer therapies have undergone a tremendous progress over the past decade. Precision medicine provides a more tailored approach, making the combination of existing therapies more precise. Different types of cancers are characterized by unique biomarkers that are targeted using various genomic approaches by clinicians and companies worldwide to achieve efficient treatment with minimal side effects. Precision medicine has two broad approaches namely stratified and personalized medicine. The driver mutations could vary within a subtype while the same driver mutations could be found across different subtypes. Precision medicine has recently gained a lot of importance for breast cancer therapy. Various kinds of mutations like hotspot mutations, gene alterations, gene amplification mutations are targeted to design a more specific therapy. Apart from these known gene mutations there are various unknown mutations. Thus, tumor heterogeneity can pose a challenge to precision medicine. For breast cancer, one of the most successful models developed in case of precision medicine is the anti-HER2 therapies as HER2 was considered to have the worst prognosis being highly malignant. But now due to the advent of HER2 receptor targeted therapies, it has a good prognosis. Moreover, precision medicine helps in identifying if the drug molecules being used for the treatment of one kind of cancer can be beneficial in the treatment of another kind of cancer as well, considering the signaling pathways and machinery is similar in most of the cancers. This reduces the time for new drug development and is economically more feasible. Precision medicine will prove to be very advantageous in case of brain metastasis.

LncRNA PlncRNA-1 accelerates the progression of prostate cancer by regulating PTEN/Akt axis

Long non-coding RNAs are key regulators of tumor development and progression, with the potential to be biomarkers of tumors. This study aimed to explore the role of PlncRNA-1 in the progression of prostate cancer (PCa). We found that PlncRNA-1 was up-regulated in 85.29% of PCa tissues and could predict the T stage of PCa patients to a certain extent. Results showed that inhibition of PlncRNA-1 expression potentially promoted cell apoptosis, suppressed the proliferation, migration, and invasion of cells, and triggered G2/M cycle arrest in vitro and in vivo. PlncRNA-1 was mainly localized in the nucleus and PlncRNA-1 expression and phosphatase and tensin homologue (PTEN) expression were negatively correlated. Mechanistically, knockdown of PlncRNA-1 increased expression levels of PTEN protein and phosphorylated PTEN protein, and decreased expression levels of Akt protein and phosphorylated Akt protein. Rescue experiments demonstrated that PTEN inhibitors abolished the changes in PTEN/Akt pathway caused by PlncRNA-1 interference. PlncRNA-1 can promote the occurrence and development of PCa via the PTEN/Akt pathway. PlncRNA-1 may, therefore, be a new candidate target for the treatment of PCa.

Quo Vadis Advanced Prostate Cancer Therapy? Novel Treatment Perspectives and Possible Future Directions

Prostate cancer is a very common disease, which is, unfortunately, often the cause of many male deaths. This is underlined by the fact that the early stages of prostate cancer are often asymptomatic. Therefore, the disease is usually detected and diagnosed at late advanced or even metastasized stages, which are already difficult to treat. Hence, it is important to pursue research and development not only in terms of novel diagnostic methods but also of therapeutic ones, as well as to increase the effectiveness of the treatment by combinational medicinal approach. Therefore, in this review article, we focus on recent approaches and novel potential tools for the treatment of advanced prostate cancer; these include not only androgen deprivation therapy, antiandrogen therapy, photodynamic therapy, photothermal therapy, immunotherapy, multimodal therapy, but also poly(ADP-ribose) polymerase, Akt and cyclin-dependent kinase inhibitors.

Kinesin family member 18B regulates the proliferation and invasion of human prostate cancer cells

Expression of kinesin family member 18B (KIF18B), an ATPase with key roles in cell division, is deregulated in many cancers, but its involvement in prostate cancer (PCa) is unclear. Here, we investigated the expression and function of KIF18B in human PCa specimens and cell lines using bioinformatics analyses, immunohistochemical and immunofluorescence microscopy, and RT-qPCR and western blot analyses. KIF18B was overexpressed in PCa specimens compared with paracancerous tissues and was associated with poorer disease-free survival. In vitro, KIF18B knockdown in PCa cell lines promoted cell proliferation, migration, and invasion, and inhibited cell apoptosis, while KIF18B overexpression had the opposite effects. In a mouse xenograft model, KIF18B overexpression accelerated and promoted the growth of PCa tumors. Bioinformatics analysis of control and KIF18B-overexpressing PCa cells showed that genes involved in the PI3K–AKT–mTOR signaling pathway were significantly enriched among the differentially expressed genes. Consistent with this observation, we found that KIF18B overexpression activates the PI3K–AKT–mTOR signaling pathway in PCa cells both in vitro and in vivo. Collectively, our results suggest that KIF18B plays a crucial role in PCa via activation of the PI3K–AKT–mTOR signaling pathway, and raise the possibility that KIF18B could have utility as a novel biomarker for PCa.

Small in Size, but Large in Action: microRNAs as Potential Modulators of PTEN in Breast and Lung Cancers

MicroRNAs (miRNAs) are well-known regulators of biological mechanisms with a small size of 19–24 nucleotides and a single-stranded structure. miRNA dysregulation occurs in cancer progression. miRNAs can function as tumor-suppressing or tumor-promoting factors in cancer via regulating molecular pathways. Breast and lung cancers are two malignant thoracic tumors in which the abnormal expression of miRNAs plays a significant role in their development. Phosphatase and tensin homolog (PTEN) is a tumor-suppressor factor that is capable of suppressing the growth, viability, and metastasis of cancer cells via downregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling. PTEN downregulation occurs in lung and breast cancers to promote PI3K/Akt expression, leading to uncontrolled proliferation, metastasis, and their resistance to chemotherapy and radiotherapy. miRNAs as upstream mediators of PTEN can dually induce/inhibit PTEN signaling in affecting the malignant behavior of lung and breast cancer cells. Furthermore, long non-coding RNAs and circular RNAs can regulate the miRNA/PTEN axis in lung and breast cancer cells. It seems that anti-tumor compounds such as baicalein, propofol, and curcumin can induce PTEN upregulation by affecting miRNAs in suppressing breast and lung cancer progression. These topics are discussed in the current review with a focus on molecular pathways.

Post-Translational Modifications That Drive Prostate Cancer Progression

While a protein primary structure is determined by genetic code, its specific functional form is mostly achieved in a dynamic interplay that includes actions of many enzymes involved in post-translational modifications. This versatile repertoire is widely used by cells to direct their response to external stimuli, regulate transcription and protein localization and to keep proteostasis. Herein, post-translational modifications with evident potency to drive prostate cancer are explored. A comprehensive list of proteome-wide and single protein post-translational modifications and their involvement in phenotypic outcomes is presented. Specifically, the data on phosphorylation, glycosylation, ubiquitination, SUMOylation, acetylation, and lipidation in prostate cancer and the enzymes involved are collected. This type of knowledge is especially valuable in cases when cancer cells do not differ in the expression or mutational status of a protein, but its differential activity is regulated on the level of post-translational modifications. Since their driving roles in prostate cancer, post-translational modifications are widely studied in attempts to advance prostate cancer treatment. Current strategies that exploit the potential of post-translational modifications in prostate cancer therapy are presented.