Selective inhibition of c-Met signaling pathways with a bispecific DNA nanoconnector for the targeted therapy of cancer.

Hepatocyte growth factor receptor (c-Met) is a suitable molecular target for the targeted therapy of cancer. Novel c-Met-targeting drugs need to be developed because conventional small-molecule inhibitors and antibodies of c-Met have some limitations. To synthesize such drugs, we developed a bispecific DNA nanoconnector (STPA) to inhibit c-Met function. STPA was constructed by using DNA triangular prism as a scaffold and aptamers as binding molecules. After c-Met-specific SL1 and nucleolin-specific AS1411 aptamers were integrated with STPA, STPA could bind to c-Met and nucleolin on the cell membrane. This led to the formation of the c-Met/STPA/nucleolin complex, which in turn blocked c-Met activation. In vitro experiments showed that STPA could not only inhibit the c-Met signaling pathways but also facilitate c-Met degradation through lysosomes. STPA also inhibited c-Met-promoted cell migration, invasion, and proliferation. The results of in vivo experiments showed that STPA could specifically target to tumor site in xenograft mouse model, and inhibit tumor growth with low toxicity by downregulating c-Met pathways. This study provided a novel and simple strategy to develop c-Met-targeting drugs for the targeted therapy of cancer.

Endoscopic Combined Drainage of One Giant and Multiple Small Pancreatic Pseudocysts: A Case Report.

A pancreatic pseudocyst (PPC) is a frequent complication of pancreatitis, often stemming from alcohol, gallstones, or hyperlipidemia. Endoscopic treatment of PPC has become the mainstream treatment. A case of one giant and multiple small PPCs was observed, manifesting as repeated abdominal bloating, abdominal pain, nausea, and vomiting after meals. Initial computed tomography scans revealed the presence of multiple PPCs. Despite ineffective medical treatment, the pseudocysts progressively increased. In response, we conducted a combined endoscopic intervention, involving Hot AXIOS (Boston Scientific, Marlborough, MA) stenting through endoscopic ultrasound-guided transmural drainage (EUS-TMD) and the placement of the endoscopic nasopancreatic drainage (ENPD) mimic stent through endoscopic retrograde pancreatography (ERP). Remarkably, after nine months of postoperative follow-up, the patient had no discomfort symptoms and the cyst disappeared. We conducted a literature review on endoscopic combined drainage for PPCs, which is still controversial. Our presented case serves as a demonstration that endoscopic combined drainage can effectively and successfully manage giant and multiple PPCs.

Cell Membrane-Anchored DNA Nanoinhibitor for Inhibition of Receptor Tyrosine Kinase Signaling Pathways via Steric Hindrance and Lysosome-Induced Protein Degradation.

Receptor tyrosine kinase (RTK) plays a crucial role in cancer progression, and it has been identified as a key drug target for cancer targeted therapy. Although traditional RTK-targeting drugs are effective, there are some limitations that potentially hinder the further development of RTK-targeting drugs. Therefore, it is urgently needed to develop novel, simple, and general RTK-targeting inhibitors with a new mechanism of action for cancer targeted therapy. Here, a cell membrane-anchored RTK-targeting DNA nanoinhibitor is developed to inhibit RTK function. By using a DNA tetrahedron as a framework, RTK-specific aptamers as the recognition elements, and cholesterol as anchoring molecules, this DNA nanoinhibitor could rapidly anchor on the cell membrane and specifically bind to RTK. Compared with traditional RTK-targeting inhibitors, this DNA nanoinhibitor does not need to bind at a limited domain on RTK, which increases the possibilities of developing RTK inhibitors. With the cellular-mesenchymal to epithelial transition factor (c-Met) as a target RTK, the DNA nanoinhibitor can not only induce steric hindrance effects to inhibit c-Met activation but also reduce the c-Met level via lysosome-mediated protein degradation and thus inhibition of c-Met signaling pathways and related cell behaviors. Moreover, the DNA nanoinhibitor is feasible for other RTKs by just replacing aptamers. This work may provide a novel, simple, and general RTK-targeting nanoinhibitor and possess great value in RTK-targeted cancer therapy.

Microvesicles from bone marrow-derived mesenchymal stem cells promote Helicobacter pylori-associated gastric cancer progression by transferring thrombospondin-2.

BACKGROUND: Our previous study found that bone marrow-derived mesenchymal stem cells (BMSCs) promote Helicobacter pylori (H pylori)-associated gastric cancer (GC) progression by secreting thrombospondin-2 (THBS2). Extracellular vesicles (EVs) are important carriers for intercellular communication, and EVs secreted by BMSCs have been shown to be closely related to tumor development. The aim of this study was to investigate whether BMSC-derived microvesicles (MVs, a main type of EV) play a role in H. pylori-associated GC by transferring THBS2. METHODS: BMSCs and THBS2-deficient BMSCs were treated with or without the supernatant of H. pylori for 12 h at a multiplicity of infection of 50, and their EVs were collected. Then, the effects of BMSC-derived MVs and THBS2-deficient BMSC-derived MVs on the GC cell line MGC-803 were assessed by in vitro proliferation, migration, and invasion assays. In addition, a subcutaneous xenograft tumor model, a nude mouse intraperitoneal metastasis model, and a tail vein injection metastasis model were constructed to evaluate the effects of BMSC-derived MVs and THBS2-deficient BMSC-derived MVs on GC development and metastasis in vivo. RESULTS: BMSC-derived MVs could be readily internalized by MGC-803 cells. BMSC-derived MVs after H. pylori treatment significantly promoted their proliferation, migration and invasion in vitro (all P < 0.05) and promoted tumor development and metastasis in a subcutaneous xenograft tumor model, a nude mouse intraperitoneal metastasis model, and a tail vein injection metastasis model in vivo (all P < 0.05). The protein expression of THBS2 was significantly upregulated after H. pylori treatment in BMSC-derived MVs (P < 0.05). Depletion of the THBS2 gene reduces the tumor-promoting ability of BMSC-MVs in an H. pylori infection microenvironment both in vitro and in vivo. CONCLUSION: Overall, these findings indicate that MVs derived from BMSCs can promote H. pylori-associated GC development and metastasis by delivering the THBS2 protein. Video Abstract.

A sequentially triggered DNA nanocapsule for targeted drug delivery based on pH-responsive i-motif and tumor cell-specific aptamer.

Targeted drug delivery with minor off-target effects is urgently needed for precise cancer treatments. Here, a sequentially triggered strategy based on double targeting elements is designed to meet this purpose. By using an acidic pH-responsive i-motif DNA and a tumor cell-specific aptamer as targeting elements, a smart dual-targeted DNA nanocapsule (ZBI5-DOX) was constructed. ZBI5-DOX can be firstly triggered by acidic pH, and then bind to target cells via aptamer recognition and thus targeted release of the carried DOX chemotherapeutics. With this smart DNA nanocapsule, the carried DOX could be precisely delivered to target SMMC-7721 tumor cells in acidic conditions. After drug treatments, selective cytotoxicity of the DNA nanocapsule was successfully achieved. Meanwhile, the DNA nanocapsule had a specific inhibition effect on target cell migration and invasion. Therefore, this sequentially triggered strategy may provide deep insight into the next generation of targeted drug delivery.

Imaging specific cell-surface sialylation using DNA dendrimer-assisted FRET.

Sialylation plays a vital role in multiple different physiologic processes, aberrant sialylation is highly related to disease development. Especially in cancer development, changed states of specific cell-surface sialylation implies rich cancer-related information. Therefore, it is necessary to image specific cell-surface sialylation for better understanding biological functions of sialylation. To meet this purpose, we designed a DNA dendrimer-assisted fluorescence resonance energy transfer (FRET) strategy in this work. By labeling multiple FRET donors and acceptors on the target molecules through metabolic oligosaccharide engineering (MOE) and targeted recognition of aptamer-tethered DNA dendrimer, the FRET was significantly improved. With the DNA dendrimer-assisted FRET strategy, specific imaging of cell-surface sialylation on SMMC-7721 and CEM cells were successfully achieved. The obtained FRET signal intensity was approximately four times higher than the control without the assistance of DNA dendrimer. Moreover, this method is competent to monitor changed states of PTK7-specific sialylation induced by tunicamycin. The proposed imaging strategy may provide a powerful tool to explore the physiological roles of specific cell-surface sialylation and the related mechanism of diseases.

Bone marrow-derived mesenchymal stem cells promote Helicobacter pylori-associated gastric cancer progression by secreting thrombospondin-2.

OBJECTIVES: Bone marrow-derived cells (BMDCs), especially mesenchymal stem cells (MSCs), may be involved in the development of Helicobacter pylori-associated gastric cancer (GC) in mice, but the specific mechanism remains unclear, and evidence from human studies is lacking. MATERIALS AND METHODS: To verify the role of BM-MSCs in H pylori-associated GC, green fluorescent protein (GFP)-labelled BM-MSCs were transplanted into the subserosal layers of the stomach in a mouse model of chronic H pylori infection. Three months post-transplantation, the mice were sacrificed, and the gastric tissues were subjected to histopathological and immunofluorescence analyses. In addition, we performed fluorescence in situ hybridization (FISH) and immunofluorescence analyses of gastric tissue from a female patient with H pylori infection and a history of acute myeloid leukaemia who received a BM transplant from a male donor. RESULTS: In mice with chronic H pylori infection, GFP-labelled BM-MSCs migrated from the serous layer to the mucosal layer and promoted GC progression. The BM-MSCs differentiated into pan-cytokeratin-positive epithelial cells and α-smooth muscle actin-positive cancer-associated fibroblasts (CAFs) by secreting the protein thrombospondin-2. FISH analysis of gastric tissue from the female patient revealed Y-chromosome-positive cells. Immunofluorescence analyses further confirmed that Y-chromosome-positive cells showed positive BM-MSCs marker. These results suggested that allogeneic BMDCs, including BM-MSCs, can migrate to the stomach under chronic H pylori infection. CONCLUSIONS: Taken together, these findings imply that BM-MSCs participate in the development of chronic H pylori-associated GC by differentiating into both gastric epithelial cells and CAFs.

Exploration of an effective training system for diagnosis of superficial esophageal squamous cell carcinoma with magnifying narrow-band imaging: Prospective research.

BACKGROUND AND AIMS: The aim was to explore an effective training system for diagnosis of superficial esophageal squamous cell carcinoma (SESCC) and its staging with magnifying narrow-band imaging (M-NBI). PATIENTS AND METHODS: Fifteen endoscopists with no or less M-NBI experience participated in this training, which consisted of four stages and five teaching methods (M-NBI classification criterion, case analysis, hands-on operation, error correction and SESCC pathological knowledge). M-NBI images were evaluated and diagnostic accuracy was analyzed. RESULTS: After training, the accuracy of distinguishing neoplastic esophageal from non-neoplastic (0.58 ± 0.16 vs. 0.95 ± 0.05, P = 0.000) and diagnosing SESCC staging (0.25 ± 0.26 vs. 0.89 ± 0.08, P = 0.000) with M-NBI were significantly increased. Participants with no M-NBI experience achieve equivalent diagnostic accuracy with less experienced trainees after the training (0.91 ± 0.08 vs. 0.92 ± 0.04, P = 0.816). Besides, diagnosis of MM (muscularis mucosa)/SM1 (submucosal) staging tumors (Stage I, 0.47 ± 0.15; Stage II-III-IV, 0.76 ± 0.12) with M-NBI was difficult for trainees and should be the focus of this training. Every teaching method could improve the diagnostic accuracy for esophageal lesions, especially for case analysis (from 0.59 ± 0.10 to 0.85 ± 0.08, P = 0.000). In addition, the average operation score for trainees was significantly increased after hands-on teaching (60.40 ± 11.11 vs. 91.80 ± 4.28, P = 0.0001). CONCLUSIONS: For novices, this training system showed efficient performance for diagnosing SESCC staging with M-NBI. Diagnosing MM/SM1 staging SESCC was difficult for beginners, and should be the focus of training.

Clinicopathological heterogeneity between primary and metastatic sites of gastroenteropancreatic neuroendocrine neoplasm.

BACKGROUND: Chromogranin A (CgA), synaptophysin (Syn) and the Ki-67 index play significant roles in diagnosis or the evaluation of the proliferative activity of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). However, little is known about whether these biological markers change during tumor metastasis and whether such changes have effect on prognosis. METHODS: We analyzed 35 specimens of both primary and metastatic tumor from 779 patients who had been diagnosed as GEP-NENs at Wuhan Union Hospital from August 2011 to October 2019. The heterogeneity of CgA, Syn and Ki-67 index was evaluated by immunohistochemical analysis. RESULTS: Among these 779 patients, the three most common sites of NENs in the digestive tract were the pancreas, rectum and stomach. Metastases were found in 311 (39.9%) patients. Among the 35 patients with both primary and metastatic pathological specimens, differences in the Ki-67 level were detected in 54.3% of the patients, while 37.1% showed a difference in CgA and only 11.4% showed a difference in Syn. Importantly, due to the difference in the Ki-67 index between primary and metastatic lesions, the WHO grade was changed in 8.6% of the patients. In addition, a Kaplan-Meier survival analysis showed that patients with Ki-67 index variation had a shorter overall survival (p = 0.0346), while neither Syn variation nor CgA variation was related to patient survival (p = 0.7194, p = 0.4829). CONCLUSIONS: Our data indicate that primary and metastatic sites of GEP-NENs may exhibit pathological heterogeneity. Ki-67 index variation is closely related to the poor prognosis of patients with tumor metastasis, but neither Syn variation nor CgA variation is related to patient prognosis. Therefore, clinicopathologic evaluation of the primary tumor and metastatic sites could be helpful for predicting the prognosis.

Do neuroendocrine carcinomas and mixed neuroendocrine-non-neuroendocrine neoplasm of the gastrointestinal tract have the same prognosis? A SEER database analysis of 12,878 cases.

BACKGROUND: Neuroendocrine carcinomas (NECs) and mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) in the gastrointestinal (GI) tract are both rare and malignant; however, it is unclear whether their prognosis is the same. METHODS: In this cross-sectional study, a total of 12,878 patients with NEC or MiNEN in the GI tract were reviewed retrospectively by searching the Surveillance, Epidemiology, and End Results (SEER) program database. Next, we compared the characteristics and survival between patients with NEC or MiNEN and further analyzed the prognostic factors for the patients. RESULTS: The data showed that patients with MiNEN had a worse prognosis as compared with patients with pure NEC in the small intestine (SI) and appendix, whereas there was no significant survival difference between NEC and MiNEN in the other parts of the GI system. On the whole, age ⩾55 years (p < 0.0001), male (p = 0.002), being diagnosed at TNM Stage II-IV (p < 0.0001) or not receiving surgical treatment (p < 0.0001) were the independent negative prognostic factors for NEC patients, whereas age ⩾55 years (p = 0.003), being diagnosed at TNM Stage III-IV (p < 0.001) or not receiving surgical treatment (p < 0.001) were identified as the independent negative prognostic factors for the MiNEN patients. Furthermore, when NECs or MiNENs were classified based on the primary tumor site, the results showed that the prognostic factors for NEC and MiNEN varied between the tumor sites. CONCLUSION: The prognostic differences between NECs and MiNENs in the GI tract are heterogeneous and site-related. Patients with appendiceal or SI MiNEN have a poorer prognosis than patients with pure appendiceal or SI NEC. Therefore, we should pay more attention to patients with MiNEN in the SI and appendix and monitor them more closely.

ANTI-INFLAMMATORY ACTIVITY OF PLATYCODIN D ON ALCOHOL-INDUCED FATTY LIVER RATS VIA TLR4-MYD88-NF-κB SIGNAL PATH.

BACKGROUND: The current study was designed to evaluate the effect of Platycodin D (PD), triterpenoid saponins extracted from the roots of Platycodon grandiflorum (PG) on alcohol-induced fatty liver (AFL) and investigate the possible mechanism. METHODS AND MATERIALS: A rat model was set up by feeding ethanol and fish oil to experimental rats, which then were treated with PD of 10, 20, 30 mg/kg body weight/day for 4 weeks, respectively, whereafter, liver function enzymes, endotoxin of serum and liver lipid were assayed by biochemical methods, cytokines, histochemistry of hepatic tissue, the protein expression of CD14 and TLR4, the mRNA expression of MD-2, MyD 88 and TRAF-6 were assayed. RESULTS: Treatment with PD on AFL rats significantly decreased the levels of serum ALT, AST and TBIL, coefficient of liver index and the hepatic tissue contents of TG, additionally and dramatically decreased serum endotoxin levels, down-regulated MD-2 and CD14 levels, as well as the mRNA expression of TLR4, MyD88 and TRAF-6, accordingly suppressed NF-κB: p65 as well as endotoxin-mediated inflammatory factors such as TNF-α and IL-6. CONCLUSIONS: Treatment with PD effectively protects against AFL through anti-inflammatory and anti-endotoxic process, and the confirmed mechanism is that PD treatment ameliorate alcoholic-induced liver injury mainly via TLR4-MyD88-NF-K: B signal path in AFL rat. List of Abbreviations: AFL: alcoholic-induced fatty liver, CD14: cluster of differentiation 14, LPS: lipopolysaccharide, LBP: lipopolysaccharide-binding protein, TLR4: toll-like receptor 4, MD-2: molecule myeloid differential protein-2, MyD 88: myeloid differentiation primary response protein 88, TRAF-6: TNF-receptor associated factor-6, NF-κB: nuclear transcription factor kappa B, IL-6: interleukin-6, TNF-α: tumor necrosis factor-α, PG: Platycodon grandiflorum, PD: Platycodin D.

[Role of PI3K/Akt signaling in hydrogen sulfide-induced alteration in expression of collagen I and III in hepatic stellate cells].

OBJECTIVE: To investigate the role of the PI3K/Akt signaling pathway in hydrogen sulfide-induced alterations in expression of collagen I and collagen III in hepatic stellate cells. METHODS: In vitro cultured rat hepatic stellate cells (HSC-T6) were treated with hydrogen sulfide, or left untreated for use as controls, and divided into groups for treatment with different inhibitors for the various factors involved in the PI3K/Akt signaling pathway. Reverse transcription-PCR was used to measure Collagen I and collagen III mRNA expression. Western blotting was used to detect the protein expression of PI3K and p-Akt, which are upstream proteins of the PI3K/Akt pathway. RESULTS: Compared with the untreated control cells, the hydrogen sulfide treated cells showed elevated expression of collagen I mRNA (F =14.635, P less than 0.05), collagen III mRNA (F =14.620, P less than 0.05), PI3K protein (F =26.672, P less than 0.05), and p-Akt (F =23.522, P less than 0.05). Compared to the cells treated with hydrogen sulfide alone, the cells treated with the various inhibitors showed lower expression of collagen I mRNA (F =14.635, P less than 0.05), collagen III mRNA (F=14.620, P less than 0.05), PI3K protein (F =26.672, P less than 0.05), and p-Akt protein (F =23.522, P less than 0.05). CONCLUSION: Hydrogen sulfide can activate the PI3K/Akt pathway and elevate the expression of collagen I and collagen III in rat hepatic stellate cells.

Association of roasting meat intake with the risk of esophageal squamous cell carcinoma of Kazakh Chinese via affecting promoter methylation of p16 gene.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) incidence is high in Kazak Autonomous Prefecture, Xinjiang, China. Roasting food has been reported to be related with the risk of various cancers and is very popular in the area, and may be related with the risk of ESCC. The promoter methylation inactivation of p16 gene can increase the risk of ESCC. Thus, we want to know whether long-term roasting food is related with the risk of ESCC by effecting the promoter methylation of p16 gene. MATERIALS AND METHODS: Ninety ESCC patients and 60 healthy subjects were recruited from Kazak Autonomous Prefecture. MassARRAY was used to detect p16 promoter methylation in ESCC tissues, as well as in normal esophageal tissues. The association between the p16 promoter methylation and daily roasting meat intake was examined. RESULTS: Daily roasting meat intake was related with the risk of ESCC (p<0.01) and the mean CpG methylation rates of p16 promoter (p<0.01). In ESCC patients, the mean methylation rates of CpG 11-12 and CpG 33-34-35 were 29.4% and 37.4%, respectively, which was significantly higher than the rates in normal esophageal tissues (16.7% and 12.4%, respectively; p<0.01). The methylation of p16 promoter is also related with daily roasting meat intake (p<0.01) in Kazakh Chinese with ESCC. For the CpG methylation of the p16 promoter in the well, moderately and poorly differentiated ESCC, there are significant differences (p<0.05) for the 19 CpG units in the ESCC and controls. CONCLUSION: Roasting meat intake was associated with the risk of ESCC via effects on the methylation of p16 promoter. These results suggest roasting food intake should be limited in the diet.