Chemosensitizing activities of cyclotides from Clitoria ternatea in paclitaxel-resistant lung cancer cells

UHPLC-ESI-ms/ms-based characterisation of phenolics and flavonoids in hydroalcoholic extract of Clitoria ternatea seeds and their cytotoxic potential against breast and pancreatic cancer

Fourteen known phenolics (1-14) and ten known flavonoids (15-24) were identified in the hydroalcoholic extract of Clitoria ternatea seeds. Phenolics such as gentisic acid (3), protocatechuic acid (5), o-coumaric acid (12) and p-coumaric acid (13) and among flavonoids, myricetin (16) were detected as the major compounds. The compounds were determined simultaneously in a multiple reaction monitoring (MRM) mode using the Acquity UPLC-H class coupled with TQD-MS/MS with an ESI source. The total phenolic and flavonoid contents were also determined. The hydroalcoholic extract evaluated for its cytotoxic effect against breast (MDA-MB-231) and pancreatic (PANC-1) cancer cells showed significant (p < 0.05) cytotoxicity with IC50 values of 45.4 and 96.5 µg/mL respectively. In addition, the cancer cells treated with the crude extract also showed elevated reactive oxygen species (ROS), upregulated caspase -8/-9/-3 activities and apoptosis of cells treated with C. ternatea extracts compared to control suggesting the pharmacological importance of this herb.

Plant peptides - redefining an area of ribosomally synthesized and post-translationally modified peptides

Covering 1965 to February 2024Plants are prolific peptide chemists and are known to make thousands of different peptidic molecules. These peptides vary dramatically in their size, chemistry, and bioactivity. Despite their differences, all plant peptides to date are biosynthesized as ribosomally synthesized and post-translationally modified peptides (RiPPs). Decades of research in plant RiPP biosynthesis have extended the definition and scope of RiPPs from microbial sources, establishing paradigms and discovering new families of biosynthetic enzymes. The discovery and elucidation of plant peptide pathways is challenging due to repurposing and evolution of housekeeping genes as both precursor peptides and biosynthetic enzymes and due to the low rates of gene clustering in plants. In this review, we highlight the chemistry, biosynthesis, and function of the known RiPP classes from plants and recommend a nomenclature for the recent addition of BURP-domain-derived RiPPs termed burpitides. Burpitides are an emerging family of cyclic plant RiPPs characterized by macrocyclic crosslinks between tyrosine or tryptophan side chains and other amino acid side chains or their peptide backbone that are formed by copper-dependent BURP-domain-containing proteins termed burpitide cyclases. Finally, we review the discovery of plant RiPPs through bioactivity-guided, structure-guided, and gene-guided approaches.

Screening for Cyclotides in Sri Lankan Medicinal Plants: Discovery, Characterization, and Bioactivity Screening of Cyclotides from Geophila repens

Cyclotides are an intriguing class of structurally stable circular miniproteins of plant origin with numerous potential pharmaceutical and agricultural applications. To investigate the occurrence of cyclotides in Sri Lankan flora, 50 medicinal plants were screened, leading to the identification of a suite of new cyclotides from Geophila repens of the family Rubiaceae. Cycloviolacin O2-like (cyO2-like) gere 1 and the known cyclotide kalata B7 (kB7) were among the cyclotides characterized at the peptide and/or transcript level together with several putative enzymes, likely involved in cyclotide biosynthesis. Five of the most abundant cyclotides were isolated, sequenced, structurally characterized, and screened in antimicrobial and cytotoxicity assays. All gere cyclotides showed cytotoxicity (IC50 of 2.0-10.2 μM), but only gere 1 inhibited standard microbial strains at a minimum inhibitory concentration of 4-16 μM. As shown by immunohistochemistry, large quantities of the cyclotides were localized in the epidermis of the leaves and petioles of G. repens. Taken together with the cytotoxicity and membrane permeabilizing activities, this implicates gere cyclotides as potential plant defense molecules. The presence of cyO2-like gere 1 in a plant in the Rubiaceae supports the notion that phylogenetically distant plants may have coevolved to express similar cytotoxic cyclotides for a specific functional role, most likely involving host defense.

Revealing the Potential Markers of N(4)-Acetylcytidine through acRIP-seq in Triple-Negative Breast Cancer

Understanding the causes of tumorigenesis and progression in triple-receptor negative breast cancer (TNBC) can help the design of novel and personalized therapies and prognostic assessments. Abnormal RNA modification is a recently discovered process in TNBC development. TNBC samples from The Cancer Genome Atlas database were categorized according to the expression level of NAT10, which drives acetylation of cytidine in RNA to N(4)-acetylcytidine (ac4C) and affects mRNA stability. A total of 703 differentially expressed long non-coding RNAs (lncRNAs) were found between high- and low-expressed NAT10 groups in TNBC. Twenty of these lncRNAs were significantly associated with prognosis. Two breast cancer tissues and their paired normal tissues were sequenced at the whole genome level using acetylated RNA immunoprecipitation sequencing (acRIP-seq) technology to identify acetylation features in TNBC, and 180 genes were significantly differentially ac4c acetylated in patients. We also analyzed the genome-wide lncRNA expression profile and constructed a co-expression network, containing 116 ac4C genes and 1080 lncRNAs. Three of these lncRNAs were prognostic risk lncRNAs affected by NAT10 and contained in the network. The corresponding reciprocal pairs were "LINC01614-COL3A1", "OIP5-AS1-USP8", and "RP5-908M14.9-TRIR". These results indicate that RNA ac4c acetylation involves lncRNAs and affects the tumor process and prognosis of TNBC. This will aid the prediction of drug targets and drug sensitivity.

A comprehensive review of microorganism-derived cyclic peptides: Bioactive functions and food safety applications

Cyclic peptides possess advanced structural characteristics of stability and play a vital role in medical treatment and agriculture. However, the biological functions of microorganism-derived cyclic peptides (MDCPs) and their applications in food industry were relatively absent. MDCPs are derived from extensive fermented food or soil. In this review, the synthesis approaches and structural characteristics are overviewed, while the interrelationship between bioactivities and functions is emphasized. This review summarizes the bioactivities of MDCPs from in vitro to in vivo, including antimicrobial activities, immune regulation, and antiviral cell activation. Their multiple functions as well as applications during food product processing, packaging, and storage are also comprehensively reviewed. Remarkably, some potential risks and cytotoxicity of MDCPs are also critically discussed. Moreover, future applications of MDCPs in the development of novel food additives and bioengineering materials are organized. Based on this review of native MDCPs, it is noteworthy that expected improvements of synthetic cyclic peptides in bioactive properties present potential valuable applications in future food, including artificial meat.

Homoharringtonine is synergistically lethal with BCL-2 inhibitor APG-2575 in acute myeloid leukemia

Background

Despite advances in targeted agent development, effective treatment of acute myeloid leukemia (AML) remains a major clinical challenge. The B-cell lymphoma-2 (BCL-2) inhibitor exhibited promising clinical activity in AML, acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL) treatment. APG-2575 is a novel BCL-2 selective inhibitor, which has demonstrated anti-tumor activity in hematologic malignancies. Homoharringtonine (HHT), an alkaloid, exhibited anti-AML activity.

Methods

The synergistic effects of APG-2575 and HHT were studied in AML cell lines and primary samples. MTS was used to measure the cell viability. Annexin V/propidium iodide staining was used to measure the apoptosis rate by flow cytometry. AML cell xenografted mouse models were established to evaluate the anti-leukemic effect of BCL-2 inhibitor, HHT and their combination in vivo. Western blot was used to determine the expression of related proteins.

Results

APG-2575 showed comparable anti-leukemic effect to the FDA-approved BCL-2 inhibitor ABT-199 in vitro and in vivo. Combined treatment of HHT with APG-2575 synergistically inhibited AML cell growth and engraftment. Mechanistically, HHT promoted degradation of myeloid cell leukemia-1 (MCL-1), which was reported to induce BCL-2 inhibitor resistant, through the PI3K/AKT/GSK3β signaling pathway.

Conclusion

Our results provide an effective AML treatment strategy through combination of APG-2575 and HHT, which is worthy of further clinical research.

Immunomodulatory peptides-A promising source for novel functional food production and drug discovery

Immunomodulatory peptides are a complex class of bioactive peptides that encompasses substances with different mechanisms of action. Immunomodulatory peptides could also be used in vaccines as adjuvants which would be extremely desirable, especially in response to pandemics. Thus, immunomodulatory peptides in food of plant origin could be regarded both as valuable suplements of novel functional food preparation and/or as precursors or possible active ingredients for drugs design for treatment variety of conditions arising from impaired function of immune system. Given variety of mechanisms, different tests are required to assess effects of immunomodulatory peptides. Some of those effects show good correlation with in vivo results but others, less so. Certain plant peptides, such as defensins, show both immunomodulatory and antimicrobial effect, which makes them interesting candidates for preparation of functional food and feed, as well as templates for design of synthetic peptides.

Cationic Clitoria ternatea Seed Peptide as a Potential Novel Bioactive Molecule

BACKGROUND

While several biologics have been reported from different parts of Clitoria ternatea, a herbaceous climber of the family Fabaceae, specific production of cationic peptides other than cyclotides (<3.7 kDa) has barely been investigated or their bioactive potential looked into.

OBJECTIVE

To uncover potential bioactivities and characteristics of novel cationic peptides from C. ternatea seeds.

METHODS

C. ternatea seed cationic peptide purified by simple and cost-effective procedures was analyzed by electrophoresis and mass spectrometry. Antimicrobial efficacy was evaluated against bacterial and fungal pathogens. Antioxidant potential was quantified by in vitro antioxidant assays. Physicochemical characterization and Tandem mass spectrometry were performed.

RESULTS

An 8.5 kDa cationic peptide purified from C. ternatea seeds was active against Candida albicans, Staphylococcus aureus, Aeromonas hydrophila and Escherichia coli at a minimum inhibitory concentration in the range of 8-32 μg/ml. This activity was totally uncompromised at pH 5-8 or after 1 h of heat treatment at 70-80 ºC, but was sensitive to protease treatment. Concentration-dependent free-radical scavenging activity and ferric-reducing capacity demonstrated the antioxidant potential of the peptide. Tandem MS analysis of trypsin-digested peptide based on shotgun proteomics detected matching peptide sequences with one or two cysteine residues but had low sequence coverage (≤17%) to known sequences in the C. ternatea protein database. Taken together, the distinct characteristics of this novel 8.5 kDa peptide clearly distinguishes it from known cyclotides of C. ternatea.

CONCLUSIONS

Insights have been obtained into the functional characteristics of what appears to be a novel cationic peptide from C. ternatea seeds, exhibiting significant antimicrobial and antioxidant activities.

Gut microbiota enhances the chemosensitivity of hepatocellular carcinoma to 5-fluorouracil in vivo by increasing curcumin bioavailability

5-Fluorouracil (5-Fu) is efficient for hepatocellular carcinoma (HCC) treatment, but fast-emerging resistance limits its usage. Curcumin is being investigated for its potential chemosensitivity, but its low oral bioavailability hinders its chemosensitivity effect in vivo. Gut microbiota modulation is considered to contribute to its bioactivities in vivo. In the current study, we demonstrate that curcumin can enhance 5-Fu chemosensitivity in HCC cells in vitro, increase the apoptosis rate, arrest the cell cycle at G2/M phase, and block the PI3k/AKT/mTOR signalling pathway by inhibiting the phosphorylation of PI3K and its downstream protein kinases. Curcumin also remarkably sensitized H22 cells to 5-Fu, allowing it to inhibit tumour growth in vivo. 16S rDNA sequencing suggests that curcumin in combination with 5-Fu significantly alters the gut microbiota composition based on alpha and beta diversity analysis compared to drug treatment alone. Gut microbiota depletion abolished curcumin's chemosensitivity effect in vivo. A pharmacodynamics study suggested that the gut microbiota increased the oral bioavailability of curcumin (AUC_(0-t) 15.24 ± 0.77 μM/h [wt] vs. 3.04 ± 0.18 μM/h [gut microbiota depleted]). In conclusion, curcumin can increase the chemosensitivity of HCC to 5-Fu in vitro and in vivo, and gut microbiota plays a key role in its effect in vivo.

Research Development, Optimization and Modifications of Anti-cancer Peptides

Anti-cancer peptides play an important role in the area of cancer inhibition. A variety of anti- cancer peptides have emerged through the extraction and structural modification of peptides from biological tissues. This review provides the research background of anti-cancer peptides, the introduction of the mechanism of anti-cancer peptides for inhibition of cancers, the discovery and development along with optimization and modifications of these peptides in the clinical application. In conclusion, it can be said that anti-cancer peptides will play a major role in the future oncologic clinic.

Natural Cyclopeptides as Anticancer Agents in the Last 20 Years

Cyclopeptides or cyclic peptides are polypeptides formed by ring closing of terminal amino acids. A large number of natural cyclopeptides have been reported to be highly effective against different cancer cells, some of which are renowned for their clinical uses. Compared to linear peptides, cyclopeptides have absolute advantages of structural rigidity, biochemical stability, binding affinity as well as membrane permeability, which contribute greatly to their anticancer potency. Therefore, the discovery and development of natural cyclopeptides as anticancer agents remains attractive to academic researchers and pharmaceutical companies. Herein, we provide an overview of anticancer cyclopeptides that were discovered in the past 20 years. The present review mainly focuses on the anticancer efficacies, mechanisms of action and chemical structures of cyclopeptides with natural origins. Additionally, studies of the structure-activity relationship, total synthetic strategies as well as bioactivities of natural cyclopeptides are also included in this article. In conclusion, due to their characteristic structural features, natural cyclopeptides have great potential to be developed as anticancer agents. Indeed, they can also serve as excellent scaffolds for the synthesis of novel derivatives for combating cancerous pathologies.

Low Expression of miR-663a Indicates Poor Prognosis and Promotes Cell Proliferation, Migration, and Invasion in Breast Cancer

INTRODUCTION

Breast cancer is one of the most common malignant cancers among women worldwide. MicroRNA-663a (miR-663a) acts as a tumor suppressor gene involved in the development of various cancers.

OBJECTIVE

The aim of this study was to reveal the clinical significance and biological function of miR-663a in breast cancer.

METHODS

The expression of miR-663a in breast cancer tissues and cells was evaluated by reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the prognostic significance of miR-663a in breast cancer. CCK-8 and Transwell assays were used to demonstrate the effect of miR-663a on breast cancer cell function.

RESULTS

We confirmed that the expression of miR-663a was significantly downregulated in breast cancer tissue samples and cell lines. Low miR-663a expression was significantly associated with lymph node metastasis, TNM stage, subtypes, and poor survival in breast cancer patients, indicating that miR-663a is an independent prognostic factor for patients with breast cancer. Cell function experiments revealed that low miR-663a expression promoted cell proliferation, migration, and invasion in breast cancer.

CONCLUSIONS

All experimental results demonstrated that miR-663a acts as a tumor suppressor that inhibits the proliferation, migration, and invasion of breast cancer cells, and miR-663a may be a prognostic biomarker and therapeutic target for breast cancer.

Decreased expression of METTL14 predicts poor prognosis and construction of a prognostic signature for clear cell renal cell carcinoma

Background

METTL14, as one of N6-methyladenosine (m6A) related genes, has been found to be associated with promoting tumorigenesis in different types of cancers. This study was aimed to investigate the prognostic value of METTL14 in clear cell renal cell carcinoma (ccRCC).

Methods

We collected ccRCC patients’ clinicopathological parameters information and 13 m6A related genes expression from The Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression analyses were conducted to investigate whether METTL14 could serve as an independent factor correlated with overall survival (OS). Gene Set Enrichment Analysis (GSEA) was carried out to identify METTL14-related signaling pathways. Moreover, a risk score (RS) was calculated to predict the prognosis of ccRCC. Quantitative real-time PCR (qRT-PCR) was also utilized to verify the expression of METTL14 in clinical specimens.

Results

Differently expressed m6A related genes were identified between ccRCC tissues and normal tissues. Therein, METTL14 was lowly expressed in ccRCC tissues and verified by qRT-PCR (all p < 0.01). Survival analysis indicated that high expression of METTL14 was associated with better OS (p = 1e−05). GSEA results revealed that high METTL14 expression was enriched in ERBB pathway, MAPK pathway, mTOR pathway, TGF-β pathway and Wnt pathway. Moreover, METTL14 was proved to be an independent prognostic factor by means of univariate and multivariate Cox regression analyses. Nomogram integrating both the METTL14 expression and clinicopathologic variables was also established to provide clinicians with a quantitative approach for predicting survival probabilities of ccRCC. Furthermore, a METTL14-based riskscore (RS) was developed with significant OS (p = 6.661e−16) and increased AUC of 0.856. Besides, significant correlated genes with METTL14 were also provided.

Conclusions

Our results indicated that METTL14 could serve as a favorable prognostic factor for ccRCC. Moreover, this study also provided a prognostic signature to predict prognosis of ccRCC and identified METTL14-related signaling pathways.

An insight into biological activities of native cyclotides for potential applications in agriculture and pharmaceutics

Cyclotides are plant-derived mini-proteins of 28 - 37 amino acids. They have a characteristic head-to-tail cyclic backbone and three disulfide cross-linkages formed by six highly conserved cysteine residues, creating a unique knotted ring structure, known as a cyclic cystine knot (CCK) motif. The CCK topology confers immense stability to cyclotides with resistance to thermal and enzymatic degradation. Native cyclotides are of interest due to their multiple biological activities with several potential applications in agricultural (e.g. biopesticides, antifungal) and pharmaceutical (e.g. anti-HIV, cytotoxic to tumor cells) sectors. The most recent application of insecticidal activity of cyclotides is the commercially available biopesticidal spray known as 'Sero X' for cotton crops. Cyclotides have a general mode of action and their potency of bioactivity is determined through their binding ability, pore formation and disruption of the target biological membranes. Keeping in view the important potential applications of biological activities of cyclotides and the lack of an extensive and analytical compilation of bioactive cyclotides, the present review systematically describes eight major biological activities of the native cyclotides from four angiosperm families viz. Fabaceae, Poaceae, Rubiaceae, Violaceae. The bioactivities of 94 cytotoxic, 57 antibacterial, 44 hemolytic, 25 antifungal, 21 anti-HIV, 20 nematocidal, 10 insecticidal and 5 molluscicidal cyclotides have been comprehensively elaborated. Further, their distribution in angiosperm families, mode of action and future prospects have also been discussed.

VEGI downregulation is correlated with nodal metastasis and poor prognosis in lung adenocarcinoma

Although the incidence of lung cancer is increasing worldwide, the molecular mechanisms for its tumorigenesis, progression and prognosis remain unknown. As a member of the tumor necrosis factor superfamily, vascular endothelial growth inhibitor (VEGI) is involved in the development and progression of many malignant diseases. In the present study, the expression of VEGI and CD31 was examined via immunohistochemistry in non-small cell lung cancer (NSCLC) tissues obtained from 150 patients with NSCLC. The inhibitory effect of VEGI on tumor-associated blood vessel formation and growth was investigated by determining the relationship between VEGI protein expression and microvascular density (MVD). Prognostic significance was evaluated using the Kaplan-Meier method. VEGI expression was downregulated or lost in 68.7% (103/150) of patients with NSCLC, an effect that was more prevalent in adenocarcinoma (AC), 76.0% (57/75), than in squamous cell carcinoma, 61.3% (46/75). A significant negative correlation was indentified between VEGI expression and lymphovascular invasion (P=0.039) and lymph node metastasis (P=0.017) in AC tissue. Additionally, MVD was significantly lower in the VEGI-rich group compared with the VEGI-poor group. The downregulation of VEGI expression was also associated with poorer overall survival (P=0.011) in patients with AC. The present study therefore provides evidence that VEGI may be a new and effective prognostic marker of lung AC.

Harnessing cyclotides to design and develop novel peptide GPCR ligands

Cyclotides are plant-derived cyclic, disulfide-rich peptides with a unique cyclic cystine knot topology that confers them with remarkable structural stability and resistance to proteolytic degradation. Recently, cyclotides have emerged as promising scaffold molecules for designing peptide-based therapeutics. Here, we provide examples of how engineering cyclotides using molecular grafting may lead to the development of novel peptide ligands of G protein-coupled receptors (GPCRs), today's most exploited drug targets. Integrating bioactive epitopes into stable cyclotide scaffolds can lead to improved pharmacokinetics and oral activity as well as selectivity and high enzymatic stability. We also discuss and highlight the importance of engineered cyclotides as novel tools to study GPCR signaling.

SETD1A augments sorafenib primary resistance via activating YAP in hepatocellular carcinoma

AIMS

Sorafenib, the approved first-line chemotherapy drug for HCC (Hepatocellular Carcinoma), remains the key treatment agent which effectively improves the survival rate of advanced HCC patients. However, the sorafenib primary resistance limits the application of sorafenib for HCC treatment. The aims of current study are to explore the role and mechanism of SETD1A (Histone Lysine Methyltransferase SET Domain Containing 1A) in sorafenib primary resistance.

MAIN METHODS

The SETD1A expression in HCC was analyzed by Gene Expression Profiling Interactive Analysis. The survival of HCC patients was analyzed by Kaplan-Meier Plotter. Western Blot and Real-time qPCR were performed to measure the protein and mRNA levels, respectively. Cell counting kit-8 assay and colony formation assay were performed to determine cell viability and proliferation. Propidium Iodide and Trypan Blue staining assays were performed to investigate cell death.

KEY FINDINGS

Here, we showed that the expression of SETD1A was markedly upregulated in both HCC cell lines and tumor tissues compared to normal hepatocytes and corresponding non-tumor liver tissues, respectively. Regardless of whether treated with sorafenib, the patients who had higher level of SETD1A underwent lower survival rate of overall. In addition, SETD1A expression was positively correlated with the IC₅₀ of sorafenib treated HCC cell lines. Furthermore, we indicated that knockdown of SETD1 augmented proliferation inhibition and cell death induced by sorafenib. SETD1A deficiency impaired YAP (Yes-associated protein) phosphorylation and activation. YAP activation contributed to SETD1A mediated sorafenib primary resistance.

SIGNIFICANCE

The current study demonstrated that SETD1A enhanced YAP activation to induce sorafenib primary resistance in HCC.

TP53 mutation influences the efficacy of treatment of colorectal cancer cell lines with a combination of sirtuin inhibitors and chemotherapeutic agents

Chemoresistance of colorectal cancer (CRC) leads to tumor recurrence and metastasis and new strategies are urgently needed to improve the outcomes of conventional chemotherapy. Sirtuin (SIRT) inhibitors prevent tumor cell growth by increasing the levels of acetylated histones and non-histones, as well as disrupting survival-related pathways. The aim of the present study was to determine the effect of SIRT inhibitors on CRC chemotherapy. The CompuSyn software program was used to evaluate the synergistic or antagonistic effects of various drugs, and the status of the protein deacetylation regulatory genes in microarray datasets were analyzed using bioinformatics. In HCT116 cells expressing wild-type (wt) TP53, SIRT inhibitors were found to act antagonistically with multiple chemotherapeutic agents (cisplatin, 5-fluorouracil, oxaliplatin, gefitinib, LY294002 and metformin), and decreased the anti-tumor effects of these agents. By contrast, SIRT inhibitors sensitized TP53-mutant (mut) SW620 cells to various chemotherapeutic drugs. Bioinformatics analysis indicated that SIRT1 and protein deacetylation related genes were highly expressed in TP53^wt CRC cells when compared to TP53^mut cells. Therefore, it was hypothesized that the likely mechanism underlying the antagonistic effect of SIRT inhibitors on TP53^wt CRC cells was a reduction in the level of stable p53 protein. The present results indicated that divergent TP53 status may translate to a different chemosensitivity profile, and suggested that a combination therapy of SIRT inhibitors and first-line chemotherapeutic drugs may be beneficial for the treatment of patients with TP53^mut CRC.

Integrative transcriptome analysis identified a BMP signaling pathway-regulated lncRNA AC068643.1 in IDH mutant and wild-type glioblastomas

Glioblastomas (GBMs) are classified into isocitrate dehydrogenase (IDH) mutant (IDH ^MT) and wild-type (IDH ^WT) subtypes, and each is associated with distinct tumor behavior and prognosis. The present study aimed to investigate differentially expressed long non-coding (lnc)RNAs and mRNAs between IDH ^MT and IDH ^WT GBMs, as well as to explore the interaction and potential functions of these RNAs. A total of 132 GBM samples with RNA profiling data (10 IDH ^MT and 122 IDH ^WT cases) were obtained from The Cancer Genome Atlas, and 62/78 and 142/219 up/downregulated lncRNAs and mRNAs between IDH ^MT and IDH ^WT GBMs were identified, respectively. Multivariate Cox analysis of the dysregulated lncRNAs/mRNAs identified three-lncRNA and fifteen-mRNA signatures with independent prognostic value, indicating that these RNAs may serve roles in determining distinct tumor behaviors and prognosis of patients with IDH ^MT/WT GBMs. Functional analysis of the three lncRNAs revealed that they were primarily associated with cell stemness or differentiation. Pearson's correlation analysis revealed that the protective lncRNA AC068643.1 was significantly positively correlated with two key bone morphogenetic protein (BMP) signaling-associated mRNAs, Bone morphogenetic protein 2 (BMP2) and Myostatin (MSTN), from the 15 mRNAs. Further in vitro studies demonstrated that BMP2 and MSTN directly stimulated AC068643.1 expression. In conclusion, the present study identified a BMP signaling pathway-regulated lncRNA AC068643.1, which may contribute to the different tumor behaviors observed between IDH ^MT and IDH ^WT GBMs.

LncRNA ZFAS1 promotes pancreatic adenocarcinoma metastasis via the RHOA/ROCK2 pathway by sponging miR-3924

Background

The mortality and morbidity rates of pancreatic adenocarcinoma have been increasing over the past two decades, and an understanding of the mechanisms underlying pancreatic adenocarcinoma progression is urgently needed. The long non-coding RNA ZFAS1 has been demonstrated to be an oncogene in some cancers, but its function and mechanism in pancreatic adenocarcinoma remain unclear.

Methods

The ZFAS1 expression level in pancreatic adenocarcinoma was predicted by bioinformatic analysis, and the expression level of ZFAS1 in pancreatic adenocarcinoma tissue samples and cell lines was further detected by quantitative real-time PCR and in situ hybridization. The functions of ZFAS1 in pancreatic adenocarcinoma in vitro and in vivo were investigated by further bioinformatic analysis. Dual-luciferase reporter assays were used to confirm the binding of ZFAS1/miR-3924 and miR-3924/ROCK2, and rescue assays were performed to further investigate the underlying mechanism.

Results

ZFAS1 overexpression in pancreatic adenocarcinoma was predicted and experimentally verified. ZFAS1 silencing inhibited pancreatic adenocarcinoma metastasis in vitro and in vivo. The competing endogenous RNA mechanism of ZFAS1 was also identified.

Conclusions

Our results demonstrated the promotive effect of ZFAS1 on pancreatic adenocarcinoma metastasis and suggested its potential role as a novel regulator of ROCK2.

NGAL protects in nasopharyngeal carcinoma by inducing apoptosis and blocking epithelial-mesenchymal transition

In recent years, neutrophil gelatinase-associated lipocalin (NGAL) has been considered to be a key molecule in different cancer types and its carcinogenesis may be related to the NGAL/MMP-9 complex. However, its expression pattern and role in nasopharyngeal carcinoma (NPC) has rarely been reported. In the current study, 158 tumor tissues from NPC patients were collected and immunohistochemistry was performed to determine the NGAL protein expression, to investigate the correlation between its expression and clinical and pathological parameters using Chi square analysis. Furthermore, by over-expressing NGAL in NPC cell lines, biological alteration of NPC cells with respect to cell proliferation, migration and invasion was analyzed. Results suggested that high expression of NGAL predicts better prognosis and longer survival. Overexpression of NGAL significantly reduced the proliferation and migration of NPC cells, and induced the apoptosis by activating caspase 3, 8 and 9, and blocking epithelial-mesenchymal transition by inhibiting mothers against decapentaplegic homolog 2/3 phosphorylation.

Prognostic value of quantitative FDG-PET in the prediction of survival and local recurrence for patients with advanced oral cancer treated with superselective intra-arterial chemoradiotherapy

The current study aimed to evaluate the relationship between 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET-CT) standardized uptake value (SUV) [pre-treatment SUV (pre-SUV) and post-treatment SUV (post-SUV)] and treatment results in patients with advanced oral cancer treated with superselective intra-arterial chemoradiotherapy (SSIACRT). A total of 37 patients with advanced oral cancer were treated with SSIACRT. The treatment consisted of superselective intra-arterial chemotherapy (docetaxel (DOC) 40 mg/mm² and nedaplatin (CDGP) 80 mg/mm²) and concurrent radiotherapy (60-70 Gy) for a period of seven weeks. Pre-SUV and post-SUV of the primary tumor were measured. Overall survival (OS) and local control (LC) rates were selected as endpoints to evaluate prognosis. The median follow-up was 40 months (range 6-112 months). The 5-year OS and LC rates were 64.5 and 85.5%, respectively, and SSIACRT achieved high LC rate even in advanced oral cancers. In the log-rank test, post-SUV was a significant prognostic factor for OS and LC rates. The results of the current study demonstrated that SSIACRT is a reliable treatment with respect to survival in advanced oral cancer and post-SUV was a significant prognostic factor for OS and LC rates.

Oridonin Induces Apoptosis of Laryngeal Carcinoma via Endoplasmic Reticulum Stress

PURPOSE

Oridonin, a bioactive diterpenoid derived from Rabdosia rubescens, has been widely reported to exhibit anticancer activity in multiple types of cancer. However, the molecular mechanism of oridonin in human laryngeal carcinoma has not been clearly elucidated. This study investigated the function of oridonin in laryngeal carcinoma to provide a research basis for laryngeal carcinoma therapy.

METHODS

The proliferation of laryngeal carcinoma Hep-2 and TU212 cells treated with oridonin was determined by MTT assay. The apoptotic induction effect of oridonin on Hep-2 and TU212 cells was analyzed by flow cytometry, Western blot analysis and caspase3 activity assay. In addition, the caspase inhibitor, Z-VAD-fmk, was synergistically treated with oridonin to detect the function of caspase cascade in oridonin-mediated apoptosis. Then, the expressions of endoplasmic reticulum (ER) stress-related proteins (GRP78, phosphorylated-PERK, phosphorylated-eIF2α and CHOP) were measured in Hep-2 and TU212 cells by Western blotting. The cells were treated with 4-PBA (an ER stress inhibitor) or knockdown of CHOP to explore the role of ER stress in oridonin-mediated apoptosis in laryngeal carcinoma. Subsequently, a nude mouse xenograft model was constructed to confirm the function of oridonin in laryngeal carcinoma in vivo.

RESULTS

Oridonin was found to significantly inhibit the proliferation of laryngeal carcinoma Hep-2 and TU212 cells in a concentration-dependent manner. Then, we confirmed that oridonin could induce apoptosis in human laryngeal carcinoma cells. The caspase inhibitor, Z-VAD-fmk, could partially reverse the pro-apoptotic effect of oridonin on human laryngeal carcinoma cells. Subsequently, Western blotting analysis demonstrated that endoplasmic reticulum (ER) stress-related proteins (GRP78, phosphorylated-PERK, phosphorylated-eIF2α and CHOP) were up-regulated in Hep-2 and TU212 cells exposed to oridonin. In addition, 4-PBA (an ER stress inhibitor) or knockdown of CHOP could antagonize oridonin-induced apoptosis. Oridonin significantly decreased the tumorigenicity of Hep-2 cells in a nude mouse xenograft model.

CONCLUSION

Oridonin-induced apoptosis of human laryngeal carcinoma through the activation of ER stress.

Cyclotides: From Structure to Function

This Review explores the class of plant-derived macrocyclic peptides called cyclotides. We include an account of their discovery, characterization, and distribution in the plant kingdom as well as a detailed analysis of their sequences and structures, biosynthesis and chemical synthesis, biological functions, and applications. These macrocyclic peptides are around 30 amino acids in size and are characterized by their head-to-tail cyclic backbone and cystine knot motif, which render them to be exceptionally stable, with resistance to thermal or enzymatic degradation. Routes to their chemical synthesis have been developed over the past two decades, and this capability has facilitated a wide range of mutagenesis and structure-activity relationship studies. In turn, these studies have both led to an increased understanding of their mechanisms of action as well as facilitated a range of applications in agriculture and medicine, as ecofriendly crop protection agents, and as drug leads or scaffolds for pharmaceutical design. Our overall objective in this Review is to provide readers with a comprehensive overview of cyclotides that we hope will stimulate further work on this fascinating family of peptides.

Esculetin Inhibits Proliferation, Invasion, and Migration of Laryngeal Cancer In Vitro and In Vivo by Inhibiting Janus Kinas (JAK)-Signal Transducer and Activator of Transcription-3 (STAT3) Activation

BACKGROUND Laryngeal cancer is one of the most common malignant tumors of the head and neck. Natural compounds in traditional Chinese medicine provide many valuable potential compounds for tumor chemotherapy. Esculetin, a coumarin derivative from several herbs, inhibits proliferation of many types of cancer cells, but its anticancer effect in laryngeal cancer is still not clear. MATERIAL AND METHODS We performed in vitro proliferation assay, invasion assay, and migration assay to assess the effect of esculetin against LC, and in vivo nude mouse xenograft animal model was used as well. Flow cytometry was conducted to analyze the effect of esculetin on cell cycle of LC cells, and Western blot analysis was used to assess the effect esculetin on the JAK-STAT signaling pathway. RESULTS Esculetin remarkably inhibits proliferation, migration, and invasion of LC cells, and reduces in vivo xenograft tumor growth and tumor weight in a dose-dependent manner. Our molecular mechanism study demonstrated that esculetin significantly inhibits STAT3 phosphorylation and blocks translocation of STAT3 into the nucleus, and esculetin also blocks the cell cycle in G1/S phase. CONCLUSIONS In a summary, by inhibiting the STAT3 activation, esculetin shows potential anticancer effects against the laryngeal cancer.

F127 poloxamer effect on cytotoxicity induction of tumour cell cultures treated with doxorubicin

INTRODUCTION

Hepatocellular carcinoma is the most common liver malignancy and the third leading cause of cancer death worldwide. One crucial limitation in the pharmacotherapy for this tumour is its chemotherapy-resistant nature produced by the overexpression of several members of the ATP-binding cassette protein family that efflux drugs out of cells, as observed with the breast cancer resistant protein (BCRP).

OBJECTIVES

This study aimed to assess the ability of Pluronic^® F127 to reverse the multidrug resistance phenotype in two human hepatocellular cell lines.

METHODS

PLC/PRF/5 and SKHep1 cells were exposed to Pluronic^® F127 at several concentrations. The effect of F127 on BCRP expression (mRNA and protein), mitochondrial transmembrane potential and cell hypodiploidy was assessed. Finally, the effect of this copolymer on cytotoxicity of doxorubicin in both hepatoma cell lines was investigated, as expressed by its reverse resistance index.

KEY FINDINGS

It was demonstrated that F127 in both cell lines contributes to chemosensitization, as shown by BCRP down-regulation, an altered mitochondrial transmembrane potential and hypodiploidy and reverse resistance index values. A remarkable dependence of these effects significantly correlated with the copolymer concentration.

CONCLUSIONS

These findings further uncover the potential usefulness of this copolymer as multidrug resistance reversal agent, increasing the efficacy of cancer therapies.

A nomogram based on 9-lncRNAs signature for improving prognostic prediction of clear cell renal cell carcinoma

Background

Abnormal expressions of long noncoding RNAs (lncRNAs) are very common in clear cell renal cell carcinoma (ccRCC), and some of these have been reported to be highly correlated with prognosis of ccRCC patients.

Methods

“edgeR” AND “DEseq” R packages were used to explore differentially expressed genes (DEGs) between normal and tumor tissues of ccRCC samples from The Cancer Genome Atlas (TCGA). Univariable Cox survival analysis, robust likelihood-based survival model and multivariable Cox regression analysis were used to identify prognostic lncRNAs and construct lncRNAs signature. Finally, a graphic nomogram based on the lncRNAs signature was developed to predict 1-, 3- and 5-year survival probability of ccRCC patients by using rms R package.

Results

8413 DEGs including 2740 lncRNAs and 4530 mRNAs were identified between normal and tumor tissues. 395 lncRNAs were found to be associated with prognosis of ccRCC patients (P < 0.05). Among these 395 prognostic lncRNAs, 9 key prognostic lncRNAs (RP13-463N16.6, CTD-2201E18.5, RP11-430G17.3, AC005785.2, RP11-2E11.9, TFAP2A-AS1, RP11-133F8.2, RP11-297L17.2 and RP11-348J24.2) were identified by using robust likelihood-based survival model. A 9-lncRNAs signature was constructed by using estimated regression coefficients of the 9 key prognostic lncRNAs. Results of χ²-test or Fisher’s exact test indicated that the 9-lncRNAs signature was significantly associated with clinicopathological characteristics such as tumor grade, T stage, N stage, M stage, TNM stage and survival outcome of ccRCC patients. Multivariate analysis showed that the 9-lncRNAs signature, age and M stage were independent prognostic factors. Finally, a graphic nomogram based on the lncRNAs signature, age and M stage was developed to predict 1-, 3- and 5-year survival probability of ccRCC patients by using rms R package.

Conclusions

A 9-lncRNAs signature associated with prognosis of ccRCC patients was constructed and a promising prognostic nomogram based on the 9-lncRNAs signature was developed for 1-, 3- and 5-year OS prediction of ccRCC patients in this study.

Low expression levels of plasma miR-141 are associated with susceptibility to gastric cancer

MicroRNAs (miRNAs/miRs) offer great potential as biomarkers for the early detection and prognosis of cancer, and the discovery of miRNAs associated with gastric cancer is required. In the present study, the differences in the plasma expression levels of miR-141 between patients with gastric cancer and healthy controls, and the role of miR-141 in gastric cancer cell oncogenesis were investigated. A follow-up study of 164 patients with gastric cancer who underwent tumor resection was conducted, and comparisons with healthy control subjects were drawn. To investigate the biological functions of miR-141, a series of in vitro and in vivo assays were conducted, including proliferation, wound-healing and Transwell assays, and a xenograft tumor model. The results demonstrated that miR-141 expression was significantly decreased in tumor tissues compared with in healthy tissues (P<0.05). Kaplan-Meier analysis revealed improved survival benefits with increased miR-141 expression (as determined using the log-rank test, P<0.001), and multivariate Cox regression analysis revealed that patients with decreased expression levels of miR-141 carried a greater risk of death (hazard ratio=2.352; 95% CI=1.379-4.012; P=0.002). The downregulation of miR-141 was also associated with WHO staging, particularly for lymph node and distant metastasis. Exogenous overexpression of miR-141 significantly inhibited the proliferative and migratory abilities of the gastric cancer cell line BGC-823. In vivo studies also demonstrated that exogenous overexpression of miR-141 in BGC-823 cells markedly reduced tumor growth in nude mice. The present study revealed that increased miR-141 expression may be a positive prognostic factor, which may be clinically beneficial in patients with gastric cancer.

Discovery and Characterization of Cyclotides from Rinorea Species

Cyclotides are macrocyclic cystine-knotted peptides most commonly found in the Violaceae plant family. Although Rinorea is the second-largest genera within the Violaceae family, few studies have examined whether or not they contain cyclotides. To further our understanding of cyclotide diversity and evolution, we examined the cyclotide content of two Rinorea species found in Southeast Asia: R. virgata and R. bengalensis. Seven cyclotides were isolated from R. virgata (named Rivi1-7), and a known cyclotide (cT10) was found in R. bengalensis. Loops 2, 5, and 6 of Rivi1-4 contained sequences not previously seen in corresponding loops of known cyclotides, thereby expanding our understanding of the diversity of cyclotides. In addition, the sequence of loop 2 of Rivi3 and Rivi4 were identical to some related noncyclic "acyclotides" from the Poaceae plant family. As only acyclotides, but not cyclotides, have been reported in monocotyledons thus far, our findings support an evolutionary link between monocotyledon-derived ancestral cyclotide precursors and dicotyledon-derived cyclotides. Furthermore, Rivi2 and Rivi3 had comparable cytotoxic activities to the most cytotoxic cyclotide known to date: cycloviolacin O2 from Viola odorata; yet, unlike cycloviolacin O2, they did not show hemolytic activity. Therefore, these cyclotides represent novel scaffolds for use in future anticancer drug design.

Plant antimicrobial peptides as potential anticancer agents

Antimicrobial peptides (AMPs) are part of the innate immune defense mechanism of many organisms and are promising candidates to treat infections caused by pathogenic bacteria to animals and humans. AMPs also display anticancer activities because of their ability to inactivate a wide range of cancer cells. Cancer remains a cause of high morbidity and mortality worldwide. Therefore, the development of methods for its control is desirable. Attractive alternatives include plant AMP thionins, defensins, and cyclotides, which have anticancer activities. Here, we provide an overview of plant AMPs anticancer activities, with an emphasis on their mode of action, their selectivity, and their efficacy.

Current scenario of peptide-based drugs: the key roles of cationic antitumor and antiviral peptides

Cationic antimicrobial peptides (AMPs) and host defense peptides (HDPs) show vast potential as peptide-based drugs. Great effort has been made in order to exploit their mechanisms of action, aiming to identify their targets as well as to enhance their activity and bioavailability. In this review, we will focus on both naturally occurring and designed antiviral and antitumor cationic peptides, including those here called promiscuous, in which multiple targets are associated with a single peptide structure. Emphasis will be given to their biochemical features, selectivity against extra targets, and molecular mechanisms. Peptides which possess antitumor activity against different cancer cell lines will be discussed, as well as peptides which inhibit virus replication, focusing on their applications for human health, animal health and agriculture, and their potential as new therapeutic drugs. Moreover, the current scenario for production and the use of nanotechnology as delivery tool for both classes of cationic peptides, as well as the perspectives on improving them is considered.