New Target For Cancer Therapy Research Articles

Design, Synthesis, and Activity Assays of Cyclin-Dependent Kinase 1 Inhibitors With Flavone Scaffolds.

Cyclin-dependent kinase 1 (CDK1) plays an indispensable role in the whole cell cycle. It has become a new target for cancer therapy. According to the binding mode of a pan-CDK inhibitor, flavopiridol with CDK1, and our previous work, a new series of flavone derivatives were discovered. Among them, compound 2a showed the best CDK1 inhibitory and anti-proliferative potencies in the in vitro activity investigation. The IC50 of 2a against CDK1 was 36.42 ± 1.12 μM vs. 11.49 μM ± 0.56 of flavopiridol. In the anti-proliferation activity assays, 2a exhibited better activity toward RAW264.7 than MCF-7 cells. The results indicated that flavone derivatives, besides inhibiting the growth of tumor cells, can also antagonize inflammatory response. Molecular docking results showed that conformation of 2a can form hydrogen bonds and various hydrophobic interactions with the key amino acid residues of CDK1. It can be used as a promising lead compound for CDK1 inhibitor development.

Exploring the Role of Sodium-Glucose Cotransporter as a New Target for Cancer Therapy

To evaluate the effects of SGLT2 inhibitors on the proliferation, tumorigenesis, migration, colony formation, apoptosis, selected gene expression pattern, and combination with known chemotherapeutic drugs in different human cancer cell lines. The antiproliferative and combined effects of SGLT2 inhibitors were evaluated by MTT assay. Cell migration was assessed using wound-healing and colony formation assays. Apoptosis assay was conducted using annexin V-FITC/ propidium iodide staining. SGLT2 gene expression was determined using real-time PCR. Canagliflozin, dapagliflozin, and ipragliflozin significantly inhibited the growth of different cancer cell lines in a dose and time-dependent manner. IC50 values after 48 hours of treatment with canagliflozin, ipragliflozin, and dapagliflozin ranged from 41.97 µM to 69.49 µM, 63.67 µM to 255.80 µM, and 167.7 µM to 435.70 µM in the examined cancer cell lines, respectively. The combined treatment of SGLT2 with doxorubicin and raloxifene separately resulted in a synergistic effect in Caco-2 and A-549 cell lines. On the other hand, the combination of SGLT2 inhibitors with cisplatin resulted in an antagonistic effect in A-549, Du-145, and Panc-1 cell lines. Canagliflozin and ipragliflozin inhibited cell migration and colony formation ability at IC50 and Sub-IC50 in the examined cancer cell lines. Canagliflozin and ipragliflozin significantly induced apoptosis at IC50 and Double-IC50 in the Du-145 cell line compared to the control. Real-time PCR showed that the treatment with 0.1 IC50 and 0.2 IC50 of both canagliflozin and ipragliflozin resulted in diminished RNA expression of SGLT2, VEGF, and Bcl-2 genes in the Du-145 cell line. SGLT2 inhibitors have antiproliferation, anti-tumorigenesis, and anti-migration effects and may induce apoptosis in cancer cells. In addition, treatment with SGLT2 inhibitors resulted in the downregulation of selected genes in the Du-145 cell line.

Expression profile of radiotherapy sensitive genes and tumor-associated immune cell infiltration and prognosis in multiple human cancers

Radiotherapy sensitive genes (RSGs), as new targets for cancer therapy, combined with tumor microenvironment (TME) and prognosis survival analysis, can provide a new idea for cancer therapy. In this study, RSGs were firstly obtained by searching the literature, then tumor and immune cell data from the Functional Annotation Of Mammalian genomes (FANTOM5) project were analyzed, with definition of two different expression patterns, tumor cell (TC) dominant and immune cell (IC) dominant, and the patterns were verified with RNA-seq data downloaded from the Gene Expression Omnibus (GEO) database. In addition, the correlation between the expression pattern of RSGs and immunotherapy was studied by integrating the seven cancers’ radiotherapy data from The Cancer Genome Atlas (TCGA). Result showed that the GEO datasets verification passing rate was greater than 60%. We determined the association between immune infiltration and patients' radiotherapy outcomes, and found that the infiltration levels of Head and Neck Squamous Carcinoma (HNSC) and Uterine Corpus Endometrial Carcinoma (UCEC) in IC-dominated RSGs were higher than those in TC, while the opposite phenomenon was observed in Glioblastoma Multiforme (GBM). The survival analysis of RSGs in seven cancers showed good prognosis in IC (70%) and TC (80%). These findings may help elucidate the influence of tumor-associated immune cell infiltration and prognosis on tumor radiotherapy outcome, which further identified radiosensitive biomarkers of clinical individualized radiotherapy.

LGR4 cooperates with PrPc to endow the stemness of colorectal cancer stem cells contributing to tumorigenesis and liver metastasis

Cancer stem cells (CSCs) are a subpopulation of cancer cells that drive tumour progression and metastasis. Anti-CSC strategies represent new targets for cancer therapies. However, CSCs are highly plastic and heterogeneous, making validation and targeting difficult without bona fide markers that define their identity, especially in a clinical setting. Here, we report that a leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) cooperates with CD44 and PrPc; the latter contributes significantly to metastatic capacity and defines the stemness characteristics of colorectal CSCs. CD44+PrPc+LGR4+ cells effectively developed into organoids and, when transplanted, generated orthotopic and metastatic tumours. Importantly, targeting LGR4 and PrPc with lentiviral shRNAs inhibited organoid development and the growth of orthotopic tumours by inhibiting Wnt/β-catenin signalling. Thus, our study offers a novel therapeutic strategy that simultaneously targets CSC stemness and metastatic properties.

SHCBP1: A Novel Potential Molecular Target for Pan- Cancer Therapy

Purpose: Although many experimentally validated evidence and clinical data support the link between SHCBP1 (SHC-Binding and Spindle-Associated 1) and cancer, there is no pan-cancer analysis available. Based on various databases, we analyzed the roles assumed by SHCBP1 in different cancers to provide new targets for cancer therapy. Methods: We used versatile public databases such as TIMER, Interactive Analysis of Gene Expression Profile, 2nd Edition (GEPIA), UALCAN, The Cancer Genome Atlas (TCGA), cBioPortal, Clinical Bioinformatics Assistant, DiseaseMeth, TISIDB, Human Protein Atlas (HPA), STRING and Database for Annotation, Visualization, and Integrated Discovery (DAVID) to analyze SHCBP1 expression, mutation, methylation in tumors, as well as its survival analysis, tumor-immune interactions and functional networks. Results: SHCBP1 was highly expressed in most tumors leading to poor prognosis and the degree of expression was positively correlated with the degree of infiltration by activated memory CD4+ T cells. We observed cancer-associated fibroblast infiltration in Breast Invasive Carcinoma (BRCA), Renal Clear Cell Carcinoma (KIRC) and Thyroid Cancer (THCA). Protein kinase activity and microtubules can influence gene enrichment, while "cell cycle", "oocyte meiosis" and "viral carcinogenesis" are possible pathways of SHCBP1 involvement in tumorigenesis. Conclusion: Altogether, our first pan-cancer analysis of SHCBP1 demonstrated its potential as a biomarker for tumor prognosis diagnosis or as a molecular target for immunotherapy.

In silico, synthesis and anticancer evaluation of benzamide tryptamine derivatives as novel eEF2K inhibitors

Eukaryotic elongation factor 2 kinase (eEF2K), a member of the atypical α-kinase family, is highly expressed in a variety of tumor tissues. Inhibition of eEF2K function can effectively kill cancer cells without affecting the function of normal cells. Therefore, eEF2K is a promising new target for cancer therapy. In this study, a series of benzamide tryptamine derivatives were designed and synthesized as novel eEF2K inhibitors. The druggability properties of the synthesized compounds were predicted in silico and performed well. The MTT assay indicated that most of these compounds displayed good antiproliferative activity against human leukemia CCRF-CEM and K562 cell lines. The structure–activity relationship (SAR) revealed that substituents with different electronic effects on the C5 position of indole ring or C2′, C4′ positions of benzene ring have a great influence on the anti-proliferative activity. Among them, 5j demonstrated the highest anti-proliferative activity with IC50 value of 1.63–3.54 μM. this compound displayed an effective eEF2K inhibition by down-regulated the level of phosphorylated eEF2 in CCRF-CEM cells. Additionally, the western blot analysis further revealed that 5j also significantly affected eEF2K-related signaling pathways. Anticancer mechanism studies have shown that 5j arrested the cell cycle in G0/G1 and induced CCRF-CEM cells apoptosis. Furthermore, 5j activated cleaved caspase-9, 8, 3 and cleaved PARP in a time-dependent manner, which suggesting that 5j induced cancer cells apoptosis through both intrinsic and extrinsic pathways. In summary, benzamide tryptamine derivative 5j represents a novel and promising lead structure for the development of eEF2K inhibitors in cancer therapy.

Discovery of two novel ALKBH5 selective inhibitors that exhibit uncompetitive or competitive type and suppress the growth activity of glioblastoma multiforme.

A group of RNA methylation enzymes is currently of interest as a new target for cancer therapy. Alpha-ketoglutarate-dependent dioxygenase B (AlkB) homolog 5 (ALKBH5) is an N6 -methyladenosine (m6 A) demethylation enzyme, and by high-throughput screening from pure small molecule compounds, we identified two novel inhibitors, Ena15 and Ena21, against it. Each compound showed either uncompetitive or competitive inhibition for 2-oxoglutarate (2OG). In addition, Ena21had little inhibitory activity for fat mass and obesity-associated protein (FTO), which is another N6 -methyladenosine demethylation enzyme, while Ena15 enhanced the demethylase activity of FTO. The predicted binding poses of both compounds with the crystal structure of ALKBH5 (PDB ID: 4NRO) were comparable with these observations pertaining to the interaction of the 2OG catalytic site in this enzyme kinetics. Furthermore, either knockdown of ALKBH5 or inhibition with Ena15 or Ena21 inhibited cell proliferation of glioblastoma multiforme-derived cell lines, decreased cell population in the synthesis phase of the cell cycle, increased m6 A RNA level, and stabilized FOXM1mRNA. Based on these results, Ena15 and Ena21 were found to be potential candidates that might help in further research into the biological function of ALKBH5.

Proteomics Study of Mesenchymal Stem Cell-Like Cells Obtained from Tumor Microenvironment of Patients with Malignant and Benign Salivary Gland Tumors.

Objective Salivary gland tumors (SGTs) show some aggressive and peculiar clinicopathological behaviors that might be related to the components of the tumor microenvironment, especially mesenchymal stem cells (MSCs)-associated proteins. However, the role of MSCs-related proteins in SGTs tumorigenesis is poorly understood. This study aimed to isolate and characterize MSCs from malignant and benign tumor tissues and to identify differentially expressed proteins between these two types of MSCs. Materials and Methods In this experimental study, MSC-like cells derived from benign (pleomorphic adenoma, n=5) and malignant (mucoepidermoid carcinoma, n=5) tumor tissues were verified by fluorochrome antibodies and flow cytometric analysis. Differentially expressed proteins were identified using two-dimensional polyacrylamide gel electrophoresis (2DE) and Mass spectrometry. Results Results showed that isolated cells strongly expressed characteristic MSCs markers such as CD44, CD73, CD90, CD105, and CD166, but they did not express or weakly expressed CD14, CD34, CD45 markers. Furthermore, the expression of CD24 and CD133 was absent or near absent in both isolated cells. Results also discovered overexpression of Annexin A4 (Anxa4), elongation factor 1-delta (EF1-D), FK506 binding protein 9 (FKBP9), cytosolic platelet-activating factor acetylhydrolase type IB subunit beta (PAFAH1B), type II transglutaminase (TG2), and s-formylglutathione hydrolase (FGH) in MSCs isolated from the malignant tissues. Additionally, heat shock protein 70 (Hsp70), as well as keratin, type II cytoskeletal 7 (CK-7), were found to be overexpressed in MSCs derived from the benign ones. ConclusionMalignant and benign SGTs probably exhibit a distinct pattern of tissue proteins that are most likely related to the metabolic pathway. However, further studies in a large number of patients are required to determine the applicability of identified proteins as new targets for cancer therapy.

Post-Translational Modifications of BRD4: Therapeutic Targets for Tumor.

Bromodomain-containing protein 4 (BRD4), a member of the bromodomain and extraterminal (BET) family, is considered to be a major driver of cancer cell growth and a new target for cancer therapy. Over 30 targeted inhibitors currently in preclinical and clinical trials have significant inhibitory effects on various tumors, including acute myelogenous leukemia (AML), diffuse large B cell lymphoma, prostate cancer, breast cancer and so on. However, resistance frequently occurs, revealing the limitations of BET inhibitor (BETi) therapy and the complexity of the BRD4 expression mechanism and action pathway. Current studies believe that when the internal and external environmental conditions of cells change, tumor cells can directly modify proteins by posttranslational modifications (PTMs) without changing the original DNA sequence to change their functions, and epigenetic modifications can also be activated to form new heritable phenotypes in response to various environmental stresses. In fact, research is constantly being supplemented with regards to that the regulatory role of BRD4 in tumors is closely related to PTMs. At present, the PTMs of BRD4 mainly include ubiquitination and phosphorylation; the former mainly regulates the stability of the BRD4 protein and mediates BETi resistance, while the latter is related to the biological functions of BRD4, such as transcriptional regulation, cofactor recruitment, chromatin binding and so on. At the same time, other PTMs, such as hydroxylation, acetylation and methylation, also play various roles in BRD4 regulation. The diversity, complexity and reversibility of posttranslational modifications affect the structure, stability and biological function of the BRD4 protein and participate in the occurrence and development of tumors by regulating the expression of tumor-related genes and even become the core and undeniable mechanism. Therefore, targeting BRD4-related modification sites or enzymes may be an effective strategy for cancer prevention and treatment. This review summarizes the role of different BRD4 modification types, elucidates the pathogenesis in the corresponding cancers, provides a theoretical reference for identifying new targets and effective combination therapy strategies, and discusses the opportunities, barriers, and limitations of PTM-based therapies for future cancer treatment.

Protein Tyrosine Phosphatase 1B (PTP1B): Insights into its New Implications in Tumorigenesis.

In vivo, tyrosine phosphorylation is a reversible and dynamic process governed by the opposing activities of protein tyrosine kinases and phosphatases. Defective or inappropriate operation of these proteins leads to aberrant tyrosine phosphorylation, which contributes to the development of many human diseases, including cancers. PTP1B, a non-transmembrane phosphatase, is generally considered a negative regulator of the metabolic signaling pathways and a promising drug target for type II diabetes and obesity. Recently, PTP1B is gaining considerable interest due to its important function and therapeutic potential in other diseases. An increasing number of studies have indicated that PTP1B plays a vital role in the initiation and progression of cancers and could be a target for new cancer therapies. Following recent advances in the aspects mentioned above, this review is focused on the major functions of PTP1B in different types of cancer and the underlying mechanisms behind these functions, as well as the potential pharmacological effects of PTP1B inhibitors in cancer therapy.

Abstract P5-09-04: Regulation of mTOR signaling pathway by ING4 in breast cancer: A new target in cancer therapy

Abstract Background: Breast cancer (BC) is one of the most diagnosed tumors in the United States. The mechanism of the disease development and progression is complex and still not fully understood. Dysregulation or change in the expression of transcription factors has been proposed as a possible cause of the disease severity and poor prognosis. The INhibitor of Growth family member 4 (ING4) is a tumor suppressor that has been connected to various cancer-related processes. Therefore, this study aims to assess the global gene regulation of BC cells by ING4 and identify the associated cellular processes and molecular pathways related to BC following ING4 loss. Methods: siRNA Knockdown and CRISPR Knockout technologies were used to deplete ING4 expression. Real-time PCR, RNA-Seq and Chip-Seq were used to identify gene expression alteration and ING4 enrichment on target promoters. Ingenuity Pathways Analysis (IPA®) was used to highlight candidates, networks and cellular processes. Results: Protein and RNA levels of ING4 were significantly reduced in MDA-231 knockdown and MCF7 knockout cells using siRNA and CRISPR technologies. RNA-Seq of BC cells revealed a large set of differentially expressed genes were regulated following ING4 loss. Key genes and biological networks related to cellular processes, including amino acid metabolism, cancer, cellular development, cellular growth and proliferation, were identified using IPA®. Chip-seq also revealed that ING4 was recruited to genes important in BC development and progression. Several genes were validated using the RT-qPCR method, and results were consistent with RNA-seq and Chip-seq data. Importantly, MDA-231 cells grown in stripped serum have shown an upregulation of the ribosomal protein S6 phosphorylation (PS6), an mTOR target protein, following ING4 knockdown. Treatment of MDA-231 cells with rapamycin blocked the phosphorylation of S6 induced by ING4 loss. An increase in S6 phosphorylation was also observed in MCF7 knockout cells grown either in regular or serum-free growth medium. The phosphorylation was reversed by amino acid transporter inhibitors JPH and BCH. Conclusion: The present study shows that ING4 regulates many genes involved in biological pathways and networks related to BC development and progression. Importantly, ING4 is a novel regulator of the mTOR pathway. Collectively, regulation of ING4 gene expression and its downstream molecules provides a novel approach in cancer treatment. Citation Format: Aymen Shatnawi, Travis Salisbury. Regulation of mTOR signaling pathway by ING4 in breast cancer: A new target in cancer therapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-09-04.

Abstract P5-06-07: Selective inhibition of fibroblast-specific domain discoidin receptor 1 (DDR1) results in reduced collagen deposition and immunomodulatory cytokine release: A potential target to modulate the activity of breast cancer associated fibroblasts

Abstract Background: Cancer-Associated Fibroblasts (CAFs) are a major cell type within breast tumor microenvironment (TME) which have emerged as a new target for cancer therapy given their contributions to tumor growth, metastasis, and suppression of the anti-tumor immune response. In the breast, CAFs are predominantly formed from conversion of tissue-resident mammary fibroblasts through mechanisms including increasing extracellular matrix (ECM) stiffness, ECM composition, hypoxia, and activating signals TGFβ and IL-6. Domain Discoidin Receptor 1 (DDR1) is a cell surface tyrosine kinase receptor expressed by epithelial and stromal cells which is activated by collagen within the TME. DDR1 expression and activity has been implicated in the development of fibrosis within the breast as well as chemotherapy resistance in several tumor types. Thus, we set out to examine whether selective inhibition of DDR1 would affect CAF immunomodulatory function to generate an immune-permissive breast microenvironment and result in reduction in stromal desmoplasia. Results: Using a human cell model of CAFs, we studied the effects of DDR1 inhibition (DDR1i) on the expression of immune modulating factors and CAF functions and features. Using a multiplex cytokine array, we observed high expression levels of key immunomodulatory cytokines IL-6, IL-8, and MCP-1 in conditioned media collected from CAF-like cells cultured in 3D collagen gels which were consequently downregulated in the presence of DDR1i. Downregulation of IL-6, IL-8, and MCP-1 induced by DDR1i was also by observed by RT-qPCR, with enhanced downregulation seen in cells cultured with increasing concentrations of collagen. Downregulation of CAF markers αSMA and FAP as well as Collagen type 1 were observed with selective DDR1 inhibition, an effect seen also with CAF-like cells stimulated with recombinant TGFβ1. Additionally, we observed reduced contraction of CAF-like cells in 3D collagen gels in the presence of DDR1i. In vivo DDR1i resulted in tissue remodeling and reduced collagen deposition as well as changes in immunomodulatory cytokine release within the mammary gland in a murine model. We observed downregulation of IL-6, as well as downregulation of Collagens type I, type IV, and MMP9. RT-qPCR also revealed reduced expression of potent chemokines CXCL1 and CXCL12 in mammary gland tissue of mice treated with DDR1i. Consistent with this, multiplexed flow cytometry demonstrated trends of increased CD45.2+ immune cell infiltration within the mammary glands and reduction of Ly6G+/Ly6C- neutrophil infiltration within the mammary gland and spleens in mice treated with DDR1i. Conclusions: Collectively, these findings suggest that breast fibroblast-specific DDR1 mediates collagen deposition and immunomodulatory function within the mammary gland and warrants further investigation as a potential target for CAF-modulating therapy in breast cancer. Citation Format: Daniel EC Fein, Nicole Traugh, Gat Rauner, Youssof Mal, Colin Trepicchio, Charlotte Kuperwasser. Selective inhibition of fibroblast-specific domain discoidin receptor 1 (DDR1) results in reduced collagen deposition and immunomodulatory cytokine release: A potential target to modulate the activity of breast cancer associated fibroblasts [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-06-07.

PrimPol: A Breakthrough among DNA Replication Enzymes and a Potential New Target for Cancer Therapy.

DNA replication can encounter blocking obstacles, leading to replication stress and genome instability. There are several mechanisms for evading this blockade. One mechanism consists of repriming ahead of the obstacles, creating a new starting point; in humans, PrimPol is responsible for carrying out this task. PrimPol is a primase that operates in both the nucleus and mitochondria. In contrast with conventional primases, PrimPol is a DNA primase able to initiate DNA synthesis de novo using deoxynucleotides, discriminating against ribonucleotides. In vitro, PrimPol can act as a DNA primase, elongating primers that PrimPol itself sythesizes, or as translesion synthesis (TLS) DNA polymerase, elongating pre-existing primers across lesions. However, the lack of evidence for PrimPol polymerase activity in vivo suggests that PrimPol only acts as a DNA primase. Here, we provide a comprehensive review of human PrimPol covering its biochemical properties and structure, in vivo function and regulation, and the processes that take place to fill the gap-containing lesion that PrimPol leaves behind. Finally, we explore the available data on human PrimPol expression in different tissues in physiological conditions and its role in cancer.

Negative Modulation of the Angiogenic Cascade Induced by Allosteric Kinesin Eg5 Inhibitors in a Gastric Adenocarcinoma In Vitro Model.

Eg5 is a kinesin essential in bipolar spindle formation, overexpressed in tumours, thus representing a new target in cancer therapy. We aimed at evaluating the anti-cancer activity of Eg5 thiadiazoline inhibitors 2 and 41 on gastric adenocarcinoma cells (AGS), focusing on the modulation of angiogenic signalling. Docking studies confirmed a similar interaction with Eg5 to that of the parent compound K858. Thiadiazolines were also tested in combination with Hesperidin (HSD). Cell cycle analysis reveals a reduction of G1 and S phase percentages when 41 is administered as well as HSD in combination with K858. Western blot reveals Eg5 inhibitors capability to reduce PI3K, p-AKT/Akt and p-Erk/Erk expressions; p-Akt/Akt ratio is even more decreased in HSD+2 sample than the p-Erk/Erk ratio in HSD+41 or K858. VEGF expression is reduced when HSD+2 and HSD+41 are administered with respect to compounds alone, after 72 h. ANGPT2 gene expression increases in cells treated with 41 and HSD+2 compared to K858. The wound-healing assay highlights a reduction in the cut in HSD+2 sample compared to 2 and HSD. Thus, Eg5 inhibitors appear to modulate angiogenic signalling by controlling VEGF activity even better if combined with HSD. Overall, Eg5 inhibitors can represent a promising starting point to develop innovative anti-cancer strategies.

Loss of 5-hydroxymethylcytosine as a Poor Prognostic Factor for Primary Testicular Diffuse Large B-cell Lymphoma.

Background: 5-Hydroxymethylcytosine (5-hmC), a stable epigenetic marker, is closely related to tumor staging, recurrence and survival, but the prognostic value of 5-hmC in primary testicular diffuse large B-cell lymphoma (PT-DLBCL) remains unclear. This study aimed to investigate the 5-hmC expression in PT-DLBCL and evaluate its prognostic value.Methods: A total of 34 patients with PT-DLBCL treated in the Department of Hematology from August 2000 to August 2020 were included in this study. The expression of 5-hmC in PT-DLBCL tissues and normal testicular tissues were assessed by immunohistochemistry. 5-hmC staining is estimated as a percentage under every nuclear staining intensity score (0-3), 0 or 1 of which were regarded as 5-hmC reduction. The quantification of 5-hmC reduction is defined as the percentage of cells with 5-hmC staining scores of 0 and 1. According 5-hmC reduction of 80%, a 5-hmC reduction of <80% is regarded as "5-hmC high-level group", and a 5-hmC reduction of ≥80% is regarded as "5-hmC low-level group". Furthermore, Cox regression model was used to evaluate the prognostic value of all covariates.Results: The median percentage of 5-hmC reduction in the PT-DLBCL group was 77.50% (60%-90%), the median 5-hmC reduction in the normal testicular tissues was 30% (20%-50%). Compared with normal testicular tissue, 5-hmC levels in PT-DLBCL tissue were significantly decreased (p<0.05). Of the 34 PT-DLBCL patients, 17 had tumors with relatively low 5-hmC expression (5-hmC reduction of ≥80%) and 17 had tumors with relatively high 5-hmC expression (5-hmC reduction of < 80%). 5-hmC expression was negatively correlated with international prognostic index (p = 0.037), while there was no significant difference in 5-hmC decrease among different groups of age at diagnosis, lactate dehydrogenase, testicular lymphoma involvement (unilateral or bilateral), Ki-67 and tumor diameter. Relatively low 5-hmC expression indicated shorter overall survival (OS) (5-year OS 50.2% vs 81.3%, p=0.022) and progression-free survival (PFS) (5-year PFS 38.5% vs 70.7%, p=0.001). Cox multivariate analysis of IPI (2-3 vs. 0-1), intrathecal prophylaxis (No vs. Yes), and 5-hmC reduction (≥80% vs. <80%) showed that 5-hmC reduction ≥80% (hazard ratio: 7.252, p = 0.005) and not receiving intrathecal prophylaxis (hazard ratio: 7.207, p =0.001) are independent risk factors for poor prognosis of PT-DLBCL.Conclusion: Our results suggested that 5-hmC decline can be identified as a poor prognostic predictor for PT-DLBCL. It is necessary to further explore the underlying mechanism of this epigenetic marker to identify methods to re-establish 5-hmC levels and provide new targets for cancer therapy.

The Endocannabinoid System as a Pharmacological Target for New Cancer Therapies.

Simple SummaryCannabinoids have been shown to suppress tumour cell proliferation, tumour invasion, metastasis, angiogenesis, chemoresistance and epithelial-mesenchymal transition and to induce tumour cell apoptosis, autophagy and immune response. This review focuses on the current status of investigations on the impact of inhibitors of endocannabinoid-degrading enzymes on tumour growth and spread in preclinical oncology research.Despite the long history of cannabinoid use for medicinal and ritual purposes, an endogenous system of cannabinoid-controlled receptors, as well as their ligands and the enzymes that synthesise and degrade them, was only discovered in the 1990s. Since then, the endocannabinoid system has attracted widespread scientific interest regarding new pharmacological targets in cancer treatment among other reasons. Meanwhile, extensive preclinical studies have shown that cannabinoids have an inhibitory effect on tumour cell proliferation, tumour invasion, metastasis, angiogenesis, chemoresistance and epithelial-mesenchymal transition (EMT) and induce tumour cell apoptosis and autophagy as well as immune response. Appropriate cannabinoid compounds could moreover be useful for cancer patients as potential combination partners with other chemotherapeutic agents to increase their efficacy while reducing unwanted side effects. In addition to the direct activation of cannabinoid receptors through the exogenous application of corresponding agonists, another strategy is to activate these receptors by increasing the endocannabinoid levels at the corresponding pathological hotspots. Indeed, a number of studies accordingly showed an inhibitory effect of blockers of the endocannabinoid-degrading enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on tumour development and spread. This review summarises the relevant preclinical studies with FAAH and MAGL inhibitors compared to studies with cannabinoids and provides an overview of the regulation of the endocannabinoid system in cancer.

Off-On Squalene Epoxidase-Specific Fluorescent Probe for Fast Imaging in Living Cells.

SQLE (squalene epoxidase) is a cell membrane-bound enzyme. It is a target of fungicides and may become a new target for cancer therapy. Therefore, monitoring the content and distribution of the key enzyme in living cells is very challenging. To achieve this goal, tetraphenyl ethylene-Ter (TPE-Ter) was first designed as a new fluorescent probe to SQLE based on its active cavity. Spectral experiments discovered that SQLE/TPE-Ter shows stronger emission with fast response time and low interference from other analytes. Molecular dynamics simulation clearly confirmed the complex structure of SQLE/TPE-Ter, and the key residues contribute to restriction of TPE-Ter single-molecular motion in the cavity. TPE-Ter-specific response to SQLE is successfully demonstrated in living cells such as LO2, HepG2, and fungi. Imaging of TPE-Ter-treated fungi indicates that it can be used to rapidly assess antifungal drug susceptibility (30 min at least). The present work provides a powerful tool to detect content and distribution of SQLE in living cells.

The Nucleus/Mitochondria-Shuttling LncRNAs Function as New Epigenetic Regulators of Mitophagy in Cancer.

Mitophagy is a specialized autophagic pathway responsible for the selective removal of damaged or dysfunctional mitochondria by targeting them to the autophagosome in order to maintain mitochondria quality. The role of mitophagy in tumorigenesis has been conflicting, with the process both supporting tumor cell survival and promoting cell death. Cancer cells may utilize the mitophagy pathway to augment their metabolic requirements and resistance to cell death, thereby leading to increased cell proliferation and invasiveness. This review highlights major regulatory pathways of mitophagy involved in cancer. In particular, we summarize recent progress regarding how nuclear-encoded long non-coding RNAs (lncRNAs) function as novel epigenetic players in the mitochondria of cancer cells, affecting the malignant behavior of tumors by regulating mitophagy. Finally, we discuss the potential application of regulating mitophagy as a new target for cancer therapy.

Stress-Induced Polyploid Giant Cancer Cells: Unique Way of Formation and Non-Negligible Characteristics.

Polyploidy is a conserved mechanism in cell development and stress responses. Multiple stresses of treatment, including radiation and chemotherapy drugs, can induce the polyploidization of tumor cells. Through endoreplication or cell fusion, diploid tumor cells convert into giant tumor cells with single large nuclei or multiple small nucleuses. Some of the stress-induced colossal cells, which were previously thought to be senescent and have no ability to proliferate, can escape the fate of death by a special way. They can remain alive at least before producing progeny cells through asymmetric cell division, a depolyploidization way named neosis. Those large and danger cells are recognized as polyploid giant cancer cells (PGCCs). Such cells are under suspicion of being highly related to tumor recurrence and metastasis after treatment and can bring new targets for cancer therapy. However, differences in formation mechanisms between PGCCs and well-accepted polyploid cancer cells are largely unknown. In this review, the methods used in different studies to induce polyploid cells are summarized, and several mechanisms of polyploidization are demonstrated. Besides, we discuss some characteristics related to the poor prognosis caused by PGCCs in order to provide readers with a more comprehensive understanding of these huge cells.

Targeting the mu-Opioid Receptor for Cancer Treatment.

Opioids are still the most effective and widely used treatments for acute and chronic pain in cancer patients. This review focuses on the impact of opioids and mu-opioid receptors (MOR) on tumor progression and providing new ideas for targeting the MOR in cancer treatment. Studies estimated that opioids facilitate tumor progression and are related to the worse prognosis in cancer patients. As the primary receptor of opioids, MOR is involved in the regulation of malignant transformation of tumors and participating in proliferation, invasion, metastasis, and angiogenesis. MOR may be a new molecular marker of malignant tumors and thus become a new target for cancer therapy, which may be beneficial to the outcomes of cancer patients.