An oncolytic system produces oxygen selectively in pancreatic tumor cells to alleviate hypoxia and improve immune activation.

INTRODUCTION: Hypoxia is one of the important reasons for the poor therapeutic efficacy of current pancreatic cancer treatment, and the dense stroma of pancreatic cancer restricts the diffusion of oxygen within the tumor. METHODS: A responsive oxygen-self-supplying adv-miRT-CAT-KR (adv-MCK) cascade reaction system to improve hypoxia in pancreatic cancer is constructed. We utilized various experiments at multiple levels (cells, organoids, in vivo) to investigate its effect on pancreatic cancer and analyzed the role of immune microenvironment changes in it through high-throughput sequencing. RESULTS: The adv-MCK system is an oncolytic adenovirus system expressing three special components of genes. The microRNA (miRNA) targets (miRTs) enable adv-MCK to selectively replicate in pancreatic cancer cells. Catalase catalyzes the overexpressed hydrogen peroxide in pancreatic cancer cells to generate endogenous oxygen, which is catalyzed by killerRed to generate singlet oxygen (1O2) and further to enhance the oncolytic effect. Meanwhile, the adv-MCK system can specifically improve hypoxia in pancreatic cancer, exert antitumor effects in combination with photodynamic therapy, and activate antitumor immunity, especially by increasing the level of γδ T cells in the tumor microenvironment. CONCLUSION: The responsive oxygen-self-supplying adv-MCK cascade reaction system combined with photodynamic therapy can improve the hypoxic microenvironment of pancreatic cancer and enhance antitumor immunity, which provides a promising alternative treatment strategy for pancreatic cancer.

Three-in-One Oncolytic Adenovirus System Initiates a Synergetic Photodynamic Immunotherapy in Immune-Suppressive Cholangiocarcinoma.

Although photodynamic immunotherapy has been promoted in the clinical practice of cholangiocarcinoma, the insensitivity to photodynamic immunotherapy remains to be a great problem. This can be largely attributed to an immune-suppressive tumor microenvironment (TME) manifested as immature myeloid cells and exhausted cytotoxic T lymphocytes. Here, a three-in-one oncolytic adenovirus system PEG-PEI-Adv-Catalase-KillerRed (p-Adv-CAT-KR) has been constructed to multiply, initiate, and enhance immune responses in photodynamic immunotherapy, using genetically-engineered KillerRed as photosensitizer, catalase as in situ oxygen-supplying mediator, and adenovirus as immunostimulatory bio-reproducible carrier. Meanwhile, PEG-PEI is applied to protect adenovirus from circulating immune attack. The administration of p-Adv-CAT-KR induces increased antigen presenting cells, elevated T cell infiltrations, and reduced tumor burden. Further investigation into underlying mechanism indicates that hypoxia inducible factor 1 subunit alpha (Hif-1α) and its downstream PD-1/PD-L1 pathway contribute to the transformation of immune-suppressive TME in cholangiocarcinoma. Collectively, the combination of KillerRed, catalase, and adenovirus brings about multi-amplified antitumor photo-immunity and has the potential to be an effective immunotherapeutic strategy for cholangiocarcinoma.

An In Situ Assembled Trapping Gel Repairs Spinal Cord Injury by Capturing Glutamate and Free Calcium Ions.

Spinal cord injury (SCI) can lead to devastating autonomic dysfunction. One of the most challenging issues for functional repair in SCI is the secondary damage caused by the increased release of glutamate and free Ca2+ from injured cells. Here, an in situ assembled trapping gel (PF-SA-GAD) is developed to sweep glutamate and Ca2+ , promoting SCI repair. The hydrogel solution is a mixture of recombinant glutamate decarboxylase 67 (rGAD67) protein, sodium alginate (SA), and pluronic F-127 (PF-127). After intrathecal administration, temperature-sensitive PF-127 promoted in situ gelation. Glutamate (Glu) is captured and decarboxylated by rGAD67 into γ-aminobutyric acid (GABA). SA reacted with the free Ca2+ to generate gellable calcium alginate. Thereby, this in situ trapping gel retarded secondary neuron injury caused by Glu and free Ca2+ during SCI. In rat models of SCI, PF-SA-GAD reduces the lesion volume and inflammatory response after SCI, restores the motor function of rats with SCI. Together, the in situ assembled trapping gel is a long-term effective and minimally invasive sweeper for the direct elimination of glutamate and Ca2+ from injury lesions and can be a novel strategy for SCI repair by preventing secondary injury.

Targeting glutamine metabolism in hepatic stellate cells alleviates liver fibrosis.

Glutamine metabolism plays an essential role in cell growth, and glutamate dehydrogenase (GDH) is a key enzyme. GDH promotes the metabolism of glutamate and glutamine to generate ATP, which is profoundly increased in multiple human cancers. Through in vitro and in vivo experiments, we verified that the small-molecule GDH inhibitor EGCG slowed the progression of fibrosis by inhibiting GDH enzyme activity and glutamine metabolism. SIRT4 is a mitochondrial enzyme with NAD that promotes ADP ribosylation and downregulates GDH activity. The role of SIRT4 in liver fibrosis and the related mechanisms are unknown. In this study, we measured the expression of SIRT4 and found that it was downregulated in liver fibrosis. Modest overexpression of SIRT4 protected the liver from fibrosis by inhibiting the transformation of glutamate to 2-ketoglutaric acid (α-KG) in the tricarboxylic acid cycle (TCA), thereby reducing the proliferative activity of hepatic stellate cells (HSCs). Collectively, our study reveals that SIRT4 controls GDH enzyme activity and expression, targeting glutamine metabolism in HSCs and alleviating liver fibrosis.

Identification of MYEOV-Associated Gene Network as a Potential Therapeutic Target in Pancreatic Cancer.

The molecular mechanism that promotes pancreatic cancer remains unclear, so it is important to find the molecular network of important genes related to pancreatic cancer. To find the key molecule of pancreatic cancer, differential gene expression analyses were analyzed by the Deseq2 package, edgeR package, and limma-voom package, respectively. Pancreatic cancer survival-related genes were analyzed by COX survival analysis. Finally, we integrated the results to obtain the significantly differentially expressed gene, MYEOV (myeloma overexpressed gene), most strongly related to survival in pancreatic cancer. Experimental verification by qRT-PCR confirmed that transcription levels of MYEOV mRNA markedly increased in pancreatic cancer cells relative to normal human pancreatic ductal epithelial cells (HPDE). Through the comprehensive analysis of multiple databases, we constructed a molecular network centered on MYEOV and found specific links between molecules in this network and tumor-associated immune cells. It was noted that MYEOV could serve as a ceRNA by producing molecular sponging effects on hsa-miR-103a-3p and hsa-miR-107, thus affecting the role of GPRC5A, SERPINB5, EGFR, KRAS, EIF4G2, and PDCD4 on pancreatic cancer progression. Besides, we also identified that infiltrated immune cells are potential mediators for the molecules in the MYEOV-related network to promote pancreatic cancer progression. It is the first report to focus on the possibility that MYEOV may act as a competing endogenous RNA (ceRNA) to form an interactive network with some pancreatic cancer-related genes such as KRAS and serve as a key therapeutic target of pancreatic cancer treatment.

Perineural Invasion and Associated Pain Transmission in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the cancers with the highest incidence of perineural invasion (PNI), which often indicates a poor prognosis. Aggressive tumor cells invade nerves, causing neurogenic inflammation; the tumor microenvironment also induces nerves to undergo a series of structural and functional reprogramming. In turn, neurons and the surrounding glial cells promote the development of pancreatic cancer through autocrine and/or paracrine signaling. In addition, hyperalgesia in PDAC patients implies alterations of pain transmission in the peripheral and central nervous systems. Currently, the studies on this topic are relatively limited. This review will elaborate on the mechanisms of tumor-neural interactions and its possible relationship with pain from several aspects that have been focused on in recent years.

Lung Cancer Cell-Derived Exosomal let-7d-5p Down-Regulates OPRM1 to Promote Cancer-Induced Bone Pain.

Cancer-induced bone pain (CIBP) is the pain caused by metastasis of malignant tumors to the bone, accounting for more than half of all chronic cancer pain, which seriously affects the quality of life among tumor patients. Up to 40% of patients with advanced lung cancer suffer from CIBP. MicroRNA (miRNA) transfers between cells through exosomes, mediates cell-to-cell communication, and performs various biological functions. Studies have shown that miRNAs secreted by cancer can modify the tumor microenvironment, but whether exosome-mediated miRNA transfer plays a role in CIBP is still unknown. In this study, the expression levels of 15 miRNAs in exosomes derived A549 cells and 18 miRNAs in exosomes derived NCI-H1299 cells were significantly up-regulated, and qRT-PCR further confirmed that the level of let-7d-5p was increased most considerably. In vitro, exosomal let-7d-5p (EXO let-7d-5p) can be taken up by dorsal root ganglion (DRG) neurons and inhibit the protein level of the target gene opioid receptor mu 1 (OPRM1). EXO let-7d-5p was further confirmed to be involved in the generation and maintenance of CIBP in vivo. Our findings clarify the molecular mechanism of CIBP caused by the inhibition of OPRM1 by EXO let-7d-5p, providing new clues and intervention targets for the prevention and treatment of CIBP.

Plasma-Derived Exosomal ALIX as a Novel Biomarker for Diagnosis and Classification of Pancreatic Cancer.

BACKGROUND: Pancreatic cancer (PC) has a dismal prognosis due to its insidious early symptoms and poor early detection rate. Exosomes can be released by various cell types and tend to be a potential novel biomarker for PC detection. In this study, we explored the proteomic profiles of plasma exosomes collected from patients with PC at different stages and other pancreatic diseases. METHODS: Plasma samples were collected from six groups of patients, including PC at stage I/II, PC at stage III/IV, well-differentiated pancreatic neuroendocrine tumor (P-NET), pancreatic cystic lesions (PCLs), chronic pancreatitis (CP), and healthy controls (HCs). Plasma-derived exosomes were isolated by ultracentrifugation and identified routinely. Isobaric tags for relative and absolute quantification (iTRAQ) based proteomic analysis along with bioinformatic analysis were performed to elucidate the biological functions of proteins. The expression of exosomal ALIX was further confirmed by enzyme-linked immunosorbent assay in a larger cohort of patients. Furthermore, receiver operating characteristic curve analysis was applied to evaluate the potential of ALIX as a novel diagnostic biomarker. RESULTS: The proteomic profile revealed a total of 623 proteins expressed among the six groups, and 16 proteins with differential degrees of abundance were found in PC vs. other pancreatic diseases (including P-NET, PCLs, and CP). Based on the results of proteomic and bioinformatic analyses, exosomal ALIX was subsequently selected as a novel biomarker for PC detection and validated in another clinical cohort. We noticed that ALIX expression was elevated in PC patients compared with patients with other pancreatic diseases or HC, and it was also closely associated with TNM stage and distant metastasis. Interestingly, the combination of exosomal ALIX and serum CA199 has greater values in differentiating both early vs. late PC (AUC value 0.872) and PC vs. other pancreatic diseases (AUC value 0.910) than either ALIX or CA199 alone. CONCLUSION: In summary, our study demonstrated that based on proteomic profiling, proteins isolated from the plasma-derived exosomes may function as ideal non-invasive biomarkers for the clinical diagnosis of PC. Importantly, exosomal ALIX combined with CA199 has great potentials in detection of PC, especially in distinguishing PC patients at early stages from advanced stages.

Analysis of T-cell receptor repertoire in peripheral blood of patients with pancreatic cancer and other pancreatic diseases.

Pancreatic cancer (PC) has been the fourth cancer-related death worldwide, diagnosed at an unresectable stage due to its rapid progression and few symptoms of this disease at early stages. The aim of this study was to determine the association between the diversity of T-cell receptor (TCR) repertoire and clinicopathological characteristics of patients with PC and other benign pancreatic diseases. In order to make a comprehensive analysis the TCR repertoire, high-throughput sequencing was used to differentiate complementarity determining region 3 (CDR3) of the TCR ß chain in peripheral blood samples from 3 PC, 3 chronic pancreatitis, 3 pancreatic cystic lesions and 3 pancreatic neuroendocrine tumour patients. We found that there were significant differences related to TCR repertoire between PC and other pancreatic diseases, and PC is a relatively immunosuppressive tumour. Changes of peripheral TCR repertoire may be used to predict the progression of PC and the response to immunotherapy. And there may exist novel-specific antigens in PC patients which could be used to design targeting immunotherapy in the nearly future.

Isoacteoside attenuates acute kidney injury induced by severe acute pancreatitis.

Severe acute pancreatitis (SAP) is a common acute abdominal disease accompanied by systemic inflammatory response syndrome, which may be complicated by acute kidney injury (AKI). Isoacteoside (ISO) is the active ingredient of Monochasma savatieri Franch. ex Maxim and has been reported to have anti­inflammatory activities. The present study detected the effects of ISO on AKI induced by SAP in rat models, and the underlying mechanism. The optimum dose of ISO for treatment of AKI induced by SAP was determined. The serum levels of TNF­α and IL­6 were estimated using an ELISA. Kidney injury was evaluated by histopathological examination, and the expression levels of nitric oxide were also detected. The expression levels of Toll­like receptor 4 (TLR4) and NF­κB p65 were measured by immunohistochemistry and western blotting. The results revealed that ISO may serve a critical role in ameliorating AKI induced by SAP. These effects may be associated with the TLR4/NF­κB signaling pathway.

Hypoxia promotes the metastasis of pancreatic cancer through regulating NOX4/KDM5A-mediated histone methylation modification changes in a HIF1A-independent manner.

BACKGROUND: Hypoxia is a characteristic of the tumor microenvironments within pancreatic cancer (PC), which has been linked to its malignancy. Recently, hypoxia has been reported to regulate the activity of important carcinogenic pathways by changing the status of histone modification. NOX4, a member of NADPH oxidase (NOX), has been found to be activated by hypoxia and promote cancer progression in several cancers. But whether it is involved in the epigenetic changes of tumor cells induced by hypoxia is still unclear, and its biological roles in PC also need to be explored. METHODS: A hypoxic-related gene signature and its associated pathways in PC were identified by analyzing the pancreatic cancer gene expression data from GEO and TCGA database. Candidate downstream gene (NOX4), responding to hypoxia, was validated by RT-PCR and western blot. Then, we evaluated the relationship between NOX4 expression and clinicopathologic parameters in 56 PC patients from our center. In vitro and in vivo assays were preformed to explore the phenotype of NOX4 in PC. Immunofluorescence, western blot and chromatin immunoprecipitation assays were further applied to search for a detailed mechanism. RESULTS: We quantified hypoxia and developed a hypoxia signature, which was associated with worse prognosis and elevated malignant potential in PC. Furthermore, we found that NADPH oxidase 4 (NOX4), which was induced by hypoxia and upregulated in PC in a HIF1A-independent manner, caused inactivation of lysine demethylase 5A (KDM5A), increased the methylation modification of histone H3 and regulated the transcription of EMT-associated gene_ snail family transcriptional repressor 1 (SNAIL1). This served to promote the invasion and metastasis of PC. NOX4 deficiency repressed hypoxia-induced EMT, reduced expression of H3K4ME3 and impaired the invasion and metastasis of PC cells; however, knockdown of KDM5A reversed the poor expression of H3KEME3 induced by NOX4 deficiency, thereby promoting EMT. CONCLUSIONS: This study highlights the prognostic role of hypoxia-related genes in PC and strong correlation with EMT pathway. Our results also creatively discovered that NOX4 was an essential mediator for hypoxia-induced histone methylation modification and EMT in PC cells.

The complete chloroplast genome of Myxopyrum hainanense and phylogenic analysis of Oleaceae.

We assembled and characterized the complete chloroplast genome sequence of Myxopyrum hainanense to investigate its phylogenetic position. The plastome is 156,064 bp in length, which is comprised of a large single-copy (LSC) region of 86,851 bp, a small single-copy (SSC) region of 17,837 bp, and two inverted repeat (IR) regions of 25,688 bp. The overall GC content of the plastome was 37.7. The new sequence comprised total 135 genes, including 87 protein-coding genes, 8 ribosomal RNA genes, and 40 tRNA genes. Phylogenetic analysis showed that M. hainanense was close to Nyctanthes arbor-tristis.

Evaluation of circulating microRNA expression in patients with trigeminal neuralgia: An observational study.

Trigeminal neuralgia (TN) is a chronic neuropathic pain that seriously affects the daily life of patients. There is increasing evidence that microRNAs (miRNAs) play an important role in the development of neuropathic pain.In this study, the TaqMan Low Density Array (TLDA) was used to analyze the serum miRNA levels of 28 TN patients, and 31 healthy people without any neuropathic pain were used as controls.The results showed that the expression profile of serum miRNA in TN patients was different from that in healthy controls. Compared with the control group, 13 miRNAs in the serum of TN patients were up-regulated and 115 miRNAs were down-regulated by >2 times. Quantitative reverse transcription PCR (RT-qPCR) analysis and receiver operating characteristic (ROC) curve were performed. The analysis further confirmed that the expression levels of 4 miRNAs, including miR-132-3p, miR-146b-5p, miR-155-5p, and miR-384, were significantly higher than those of healthy controls, and the difference was statistically significant.This study preliminarily confirmed the changes of serum miRNA expression profile in TN patients. Among them, 4 kinds of serum miRNA are likely to be related to the occurrence and development of TN.

Preparation of microspheres encapsulating sorafenib and catalase and their application in rabbit VX2 liver tumor.

BACKGROUND: Transcatheter arterial chemoembolization (TACE) is extensively used in the treatment of advanced hepatocellular carcinoma (HCC). However, the efficacy of TACE is usually limited to secondary tumor hypoxia and hypoxia-related tumor angiogenesis. METHODS: In this study, poly(lactic-co-glycolic acid) (PLGA) microspheres (SOR-CAT-PLGA MSs) encapsulating sorafenib (SOR) and catalase (CAT) were prepared by double-emulsion solvent diffusion method. Sorafenib inhibits tumor angiogenesis, and catalase decomposes hydrogen peroxide (H2O2) to generate oxygen in the tumor. RESULTS: In vitro and in vivo, SOR -CAT-PLGA MSs could significantly improve the efficacy of hepatic artery embolization in the treatment of rabbit VX2 liver tumors, regulate tumor hypoxia and immunosuppressive microenvironment, then achieved near-complete and rapid necrosis of liver tumors. CONCLUSIONS: The application of new SOR -CAT-PLGA MSs in hepatic artery chemoembolization of rabbit VX2 liver tumor is a promising approach to improve the therapeutic effect of liver tumors and has a broad clinical application prospect.

BET protein inhibitor JQ1 downregulates chromatin accessibility and suppresses metastasis of gastric cancer via inactivating RUNX2/NID1 signaling.

Chromatin accessibility is critical for tumor development, whose mechanisms remain unclear. As a crucial regulator for chromatin remodeling, BRD4 promotes tumor progression by regulating multiple genes. As a small-molecule inhibitor of BRD4, JQ1 has potent chemotherapeutic activity against various human cancers. However, whether JQ1 has potential anti-tumor effects and how JQ1 regulates global transcription in gastric cancer (GC) remain largely unknown. In this research, we found BRD4 was highly expressed in GC tissues and was significantly associated with poor prognosis. JQ1 inhibited the proliferation and induced apoptosis of GC cells in vitro. Besides, JQ1 suppressed the migration and invasion of cancer cells by inducing MET. Notably, an assay for transposase-accessible chromatin using sequencing (ATAC-seq) data showed that JQ1 obviously downregulated the chromatin accessibility of GC cells and differentially accessible regions were highly enriched for RUNX2-binding motifs. Combinational analysis of ATAC-seq and RNA-seq data discovered NID1 as the downstream target of JQ1 and JQ1 reduced NID1 expression in GC cells. Chromatin immunoprecipitation, luciferase reporter gene assay, and rescue experiments all confirmed that RUNX2/NID1 axis was responsible for JQ1-inhibiting metastasis of GC cells. What's more, high expression of NID1 in GC tissues also predicted poor survival outcome of cancer patients and NID1 knockdown prohibited migration and invasion of cancer cells via partially inducing MET. Finally, in vivo models showed that JQ1 prevented GC growth and suppressed cancer metastasis. In conclusion, JQ1 inhibits the malignant progression of GC by downregulating chromatin accessibility and inactivating RUNX2/NID1 signaling. In addition, NID1 is also a novel therapeutic target for progressive GC patients.

Honeysuckle-derived microRNA2911 directly inhibits varicella-zoster virus replication by targeting IE62 gene.

Varicella-zoster virus (VZV) leads to chicken pox on primary infection and herpes zoster on reactivation. Recent studies suggest that microRNA2911 (MIR2911), honeysuckle (HS)-encoded atypical microRNA, has potential as a therapeutic agent against influenza and EV71 virus infections. Here, we report that MIR2911 directly inhibits VZV replication by targeting the IE62 gene. The luciferase reporter assay and bioinformatics prediction revealed that MIR2911 could target the IE62 gene of VZV. The VZV-encoded IE62 protein expression was inhibited significantly by synthetic MIR2911, while the expression of the mutants, whose MIR2911-binding sites were modified, was not inhibited. The RNA extracted from HS decoction and synthetic MIR2911 considerably suppressed VZV infection. However, it did not influence viral replication of a mutant virus with alterations in the nucleotide sequences of IE62. At the same time, the RNA extracted from HS decoction treated with the anti-MIR2911 antagomir could not inhibit the VZV replication, demonstrating that VZV replication was specifically and sufficiently inhibited by MIR2911. These results indicated that, by targeting the IE62 gene, MIR2911 may effectively inhibit VZV replication. Our results also suggest a potential novel strategy for the treatment and prevention of diseases caused by VZV infection.

Honeysuckle-encoded microRNA2911 inhibits Enterovirus 71 replication via targeting VP1 gene.

Enterovirus 71 (EV71) is the primary pathogen of hand-foot-and-mouth disease (HFMD) in children and virus infections are associated with severe neurological dysfunctions and even death. MIR2911 is a honeysuckle-encoded atypical microRNA with extreme stability. Here, we report that MIR2911 directly inhibits EV71 replication by targeting the VP1 gene. Bioinformatics prediction and luciferase reporter assay showed that MIR2911 could target the VP1 gene of EV71. Transfection experiments using synthetic MIR2911 and extracted RNA from HS decoction shown that each of these preparations was capable of inhibiting EV71 VP1 protein expression; however, these preparations did not impact EV71 mutants in which the MIR2911-binding sites were mutated. Furthermore, EV71 replication was increased by antagomirs against MIR2911 in the HS decoction, implying that MIR2911 was physiologically functional in controlling EV71 replication in vitro. These results indicated that, by targeting VP1 gene, MIR2911 may effectively inhibit EV71 replication. Our results also provide a potential novel strategy on the therapy and/or prevention of HFMD originating from EV71 virus infection.

H5N1 influenza virus-specific miRNA-like small RNA increases cytokine production and mouse mortality via targeting poly(rC)-binding protein 2.

Infection of H5N1 influenza virus causes the highest mortality among all influenza viruses. The mechanisms underlying such high viral pathogenicity are incompletely understood. Here, we report that the H5N1 influenza virus encodes a microRNA-like small RNA, miR-HA-3p, which is processed from a stem loop-containing viral RNA precursor by Argonaute 2, and plays a role in enhancing cytokine production during H5N1 infection. Mechanistic study shows that miR-HA-3p targets poly(rC)-binding protein 2 (PCBP2) and suppresses its expression. Consistent with PCBP2 being an important negative regulator of RIG-I/MAVS-mediated antiviral innate immunity, suppression of PCBP2 expression by miR-HA-3p promotes cytokine production in human macrophages and mice infected with H5N1 virus. We conclude that miR-HA-3p is the first identified influenza virus-encoded microRNA-like functional RNA fragment and a novel virulence factor contributing to H5N1-induced 'cytokine storm' and mortality.

sTRAIL-iRGD is a promising therapeutic agent for gastric cancer treatment.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively kills tumor cells and augments chemotherapeutics in vivo. Here, we developed sTRAIL-iRGD, a recombinant protein consisting of sTRAIL fused to CRGDKGPDC, a C-terminal end binding peptide with an integrin-binding arginine-glycine-aspartic acid (iRGD) motif. CRGDKGPDC is a tumor-homing peptide with high penetration into tumor tissue and cells. We found that sTRAIL-iRGD internalized into cultured gastric cancer tumor cells and localized to both the tumor mass in vivo and three-dimensional multicellular spheroids in vitro. sTRAIL-iRGD had an antitumor effect in tumor cell lines, multicellular spheroids and nude mice with tumors. Repeated treatment with sTRAIL-iRGD reduced tumor growth and volume in vivo. Mice treated with sTRAIL-iRGD and paclitaxel (PTX) in combination showed no sign of sTRAIL-iRGD-related liver toxicity. Our data suggest that sTRAIL-iRGD is a promising anti-gastric cancer agent with high selectivity and limited systemic toxicity.

Tumor-penetrating peptide fused to a pro-apoptotic peptide facilitates effective gastric cancer therapy.

KLA (sequence, KLAKLAKKLAKLAK) is a peptide which leads to programmed cell death by disrupting the mitochondrial membrane. However, low penetration in tumors greatly limits its application and efficacy. To develop a KLA-based cancer therapy, KLA-iRGD, a recombinant protein was constructed. It consists of the KLA peptide and iRGD (CRGDKGPDC), a tumor-homing peptide with high penetration into tumor tissue and cells. The conjugated KLA exhibits pro-apoptotic activity to prevent the growth of a tumor once it is inside the cell. Once KLA-iRGD is internalized in cultured tumor cells, via the activation of the receptor neuropilin-1, it spreads extensively throughout the mass of the tumor. The recombinant KLA-iRGD protein showed antitumor activity in vivo in mice and in vitro in tumor cell lines. Repeated treatment with KLA-iRGD greatly prevented tumor growth, resulting in a considerable reduction in tumor volume. According to our data, KLA-iRGD may serve as a potential anticancer agent with limited systemic toxicity and high selectivity for the treatment of MKN45 gastric cancer, which may lead to the enhancement of new targeted anticancer agents.