Eudragit S100 prepared pH-responsive liposomes-loaded betulinic acid against colorectal cancer in vitro and in vivo.

This study aimed to develop polymer Eudragit S100 for preparing pH-responsive liposomes-loaded betulinic acid (pH-BA-LP) to improve the therapeutic index of chemotherapy for colorectal cancer. BA-loaded liposomes were coated with Eudragit S100 by a thin film dispersion and easily scalable pH-driven method. The prepared liposomes were evaluated for size, surface morphology, entrapment efficiency, stability, in vitro drug release, and antitumor activity. In particular, pH-BA-LP showed advantages such as lower size (<100 nm), encapsulation efficiency of 90%, high stability, and stably cumulative release. By detecting the antitumor effects of pH-BA-LP in vivo, it showed that the tumor proliferation and cell migration were significantly inhibited in colorectal cancer. The pH-BA-LP also inhibited tumor growth via the regulation of Akt/TLR-mediated signalling and significantly down-regulated the expression of NFAT1 and NFAT4 proteins. It was found that pH-BA-LP can increase NK cells and CD3+ cells in tumor tissues, and the proportion of CD8+ cells in CD3+ cells was also increased, which proved that pH-BA-LP can play an antitumor effect by enhancing the autoimmunity level in tumor-bearing mice. The positive infiltration rates of CD8 and CD68 were increased and CD163 was relatively decreased by using pH-BA-LP, which proved that pH-BA-LP can regulate the immune infiltration levels in tumor-bearing mice. Therefore, the present work provides an effective method to prepare pH-responsive polymer-coated liposomes for colonic delivery with biologically active compounds.

Triterpenoids Extracted from Rhus chinensis Mill Act Against Colorectal Cancer by Inhibiting Enzymes in Glycolysis and Glutaminolysis: Network Analysis and Experimental Validation.

Background: Rhus chinensis Mill is a traditional Chinese medicine (TCM) mostly used to treat several cancer types. Although previous studies have found that certain ingredients of R. chinensis such as flavonoids can inhibit tumor cell proliferation [e.g. colorectal cancer (CRC)], systematic research on the mechanism underlying anticancer effect of active compounds like triterpenoids (TER) is lacking.Study Design: Herein, the concept of "network pharmacology primarily based on active compounds" was applied to explore the anticancer mechanisms of TER extract from R. chinensis. In this regard, potential targets and pathways of glycolysis and glutaminolysis form the basis for the anti-CRC effect of triterpenoids. Network pharmacology was used to predict several key proteins in the metabolic pathways, which were further verified via western blot and metabolomics methods.Results: Our results showed that the total TER in R. chinensis remarkably inhibited the proliferation and apoptosis of SW620 cells. The top 4 compounds of TER (viz., betulinic acid-BTA, betulonic acid-BTOA, betulin-BT, and semialactic acid-SA) were confirmed through the detection of UPLC-MS and analysis of cell proliferation assays. Mechanistically, this study revealed that TER plays an anti-CRC role through key targets, such as ENO1, ALDOA, PFKFB3, PKM2, and LDHA, as well as key glycolytic and glutaminolytic pathways.Conclusion: Collectively, these results have provided new insights into the mechanism underlying anti-CRC effect of triterpenoids extract obtained from R. chinensis, mainly through combination of compositional quantitative analysis, network pharmacology, and experimental verification.

Strategies to target energy metabolism in consensus molecular subtype 3 along with Kirsten rat sarcoma viral oncogene homolog mutations for colorectal cancer therapy.

Alterations in cellular energy metabolism play a critical role in colorectal cancer (CRC), which has been identified as the definition of consensus molecular subtypes (CMSs), and CMS3 tumors exhibit energy metabolism signatures along with Kirsten rat sarcoma viral oncogene homolog (KRAS)-activating mutations. This review summarizes the relationship between CMS3 tumors associated with mutated KRAS and energy metabolism in CRC, especially for the dysregulated energy metabolism that affects tumor cell proliferation, invasion, and migration. Furthermore, this review concentrates on the role of metabolic genes and factors and signaling pathways, which coupled with a primary energy source connected with the CMS3 associated with mutated KRAS, induce metabolic alterations. The strategies to target energy metabolism for the metabolic alterations in mutated KRAS CRC are also introduced. In conclusion, dysregulated energy metabolism has a close relationship with mutated KRAS in CMS3 tumors. Therefore, selective inhibitors or agents against metabolic targets or KRAS signaling may be clinically useful for CMS3 tumor treatment through a personalized approach for patients with cancer.

Strategies for targeting energy metabolism in Kirsten rat sarcoma viral oncogene homolog -mutant colorectal cancer.

Alterations in cellular energy metabolism play critical roles in colorectal cancer (CRC). These alterations, which correlate to KRAS mutations, have been identified as energy metabolism signatures. This review summarizes the relationship between colorectal tumors associated with mutated KRAS and energy metabolism, especially for the deregulated energy metabolism that affects tumor cell proliferation, invasion, and migration. Furthermore, this review will concentrate on the role of metabolic genes, factors and signaling pathways, which are coupled with the primary energy source connected with the KRAS mutation that induces metabolic alterations. Strategies for targeting energy metabolism in mutated KRAS CRC are also introduced. In conclusion, deregulated energy metabolism has a close relationship with KRAS mutations in colorectal tumors. Therefore, selective inhibitors, agents against metabolic targets or KRAS signaling, may be clinically useful for colorectal tumor treatment through a patient-personalized approach.

New strategies for targeting glucose metabolism-mediated acidosis for colorectal cancer therapy.

Colorectal cancer (CRC) is a heterogeneous group of diseases that are the result of abnormal glucose metabolism alterations with high lactate production by pyruvate to lactate conversion, which remodels acidosis and offers an evolutional advantage for tumor cells, even enhancing their aggressive phenotype. This review summarizes recent findings that involve multiple genes, molecules, and downstream signaling in the dysregulated glycolytic pathway, which can allow a tumor to initiate acid byproducts and to progress, thereby resulting in acidosis commonly found in the tumor microenvironment of CRC. Moreover, the relationship between CRC cells and the tumor acidic microenvironment, especially for regulating lactate production and lactate dehydrogenase A levels, is also discussed, as well as comprehensively defining different aspects of glycolytic pathways that affect cancer cell proliferation, invasion, and migration. Furthermore, this review concentrates on glucose metabolism-mediated transduction factors in CRC, which include acid-sensing ion channels, triosephosphate isomerase and key glycolysis-related enzymes that regulate glycolytic metabolites, coupled with the effect on tumor cell glycolysis as well as signaling pathways. In conclusion, glucose metabolism mediated by glycolytic pathways that are integral to tumor acidosis in CRC is demonstrated. Therefore, selective metabolic inhibitors or agents against these targets in glucose metabolism through glycolytic pathways may be clinically useful to regulate the tumor's acidic microenvironment for CRC treatment and to identify specific targets that regulate tumor acidosis through a cancer patient-personalized approach. Furthermore, strategies for modifying the metabolic processes that effectively inhibit cancer cell growth and tumor progression and activate potent anticancer effects may provide more effective antitumor prospects for CRC therapy.

Early prediction of intestinal mucosal barrier function impairment by elevated serum procalcitonin in rats with severe acute pancreatitis.

OBJECTIVES: The aim of this study was to evaluate serum procalcitonin (PCT) levels as a prognostic indicator of intestinal barrier function impairment in rats with severe acute pancreatitis (SAP). METHODS: Thirty-six male Sprague Dawley rats were randomly grouped into SAP group (injected sodium taurocholate via biliopancreatic duct), Gln group (gavaged with glutamine after modeling), and control group. Blood, pancreatic, and terminal ileum tissues were obtained from the rats after 6 h of modeling. Serum amylase (Amy) levels were determined using an automatic biochemical detector, while endotoxin (ET), diamine oxidase (DAO), and PCT levels were measured by ELISA test. The pathology of pancreatic and small intestine tissues were observed. PCT protein expression in intestinal tissues were detected by immunohistochemistry and western blot. RESULT: Pancreatic and intestinal injuries in Gln group were significantly lower than SAP group. Serum amylase, DAO, and PCT levels in SAP and Gln groups differed greatly and were significantly higher than control group. Immuno-histochemistry and western blot results showed that PCT protein expression levels in small intestine tissues of SAP group were higher than Gln group and control group. Serum PCT levels had a significant correlation with serum endotoxin, DAO levels and intestinal mucosal injury scores. CONCLUSION: PCT expression in serum and intestinal tissues in SAP rats increased significantly in the early stages of SAP, and was closely related to the onset and degree of intestinal barrier function impairment. Thus, our results showed that measuring serum PCT can be used to predict intestinal mucosal barrier function impairment in SAP rats.

Ras/ERK signaling pathway is involved in curcumin-induced cell cycle arrest and apoptosis in human gastric carcinoma AGS cells.

Curcumin, the biologically active compound from the rhizome of Curcuma longa, could inhibit cell growth and induce apoptosis in gastric carcinoma. However, the underlying mechanism of curcumin on gastric carcinoma cells still needs further investigation. In this study, morphological observation indicated that curcumin inhibited the proliferation of AGS cells in a dose-dependent manner. According to the flow cytometric analysis, curcumin treatment resulted in G2/M arrest in AGS cells, accompanied with an increased expression of cyclin B1 and a decreased expression of cyclin D1. In addition, DNA ladders were observed by gel electrophoresis. Meanwhile, the activities of caspase-3, -8, and -9 were also enhanced in curcumin-treated AGS cells. Nevertheless, the increased activities could be inhibited by benzyloxycarbonyl-Val-Ala-Asp (OME)-fluoromethylketone (z-VAD-fmk), which suggested that the apoptosis was caspase-dependent. Furthermore, downregulation of rat sarcoma (Ras) and upregulation of extracellular-signal-regulated kinase (ERK) were also observed in AGS cells treated with curcumin by Western blot. U0126, an ERK inhibitor, blocked curcumin-induced apoptosis. The results suggested that curcumin inhibited the growth of the AGS cells and induced apoptosis through the activation of Ras/ERK signaling pathway and downstream caspase cascade, and curcumin might be a potential target for the treatment of gastric carcinoma.

Astragaloside IV inhibits the up-regulation of Wnt/ß-catenin signaling in rats with unilateral ureteral obstruction.

OBJECTIVE: To investigate the effect of Astragaloside IV (AS-IV) on the regulation of the Wnt/ß-catenin signaling pathway in rats with unilateral ureteral obstruction (UUO). METHODS: Rat renal interstitial fibrosis models were prepared using unilateral ureteral ligation. Rats were randomly divided into sham group, sham group with AS-IV (33mg/kg), unilateral ureteral obstruction group, and unilateral ureteral obstruction group receiving varied doses of AS-IV (3.3, 10, and 33 mg/kg). Immunohistochemical analysis, real-time fluorescence quantitative PCR (FQ-PCR), and western blot were used to detect the expression of genes and proteins associated with the Wnt/ß-catenin signaling pathway in renal tissues. RESULTS: Levels of Wnt3, Wnt4, and Frizzled gene expression increased significantly in the UUO model; AS-IV was associated with the downregulation of the expression of Wnt3, Wnt4, Frizzled4, p-LRP5, p-LRP6, disheveled, ß-catenin, LEF-1, TCF-1, Snail, Jagged 1, Twist, MMP2, and MMP7 proteins in a concentration-dependent manner, while the expression of APC, CK1, and E-cadherin was increased. CONCLUSIONS: AS-IV effectively inhibits the up-regulation of proteins in the Wnt/ß-catenin signaling pathway in UUO-model rats, indicating its possible inhibitory effects on renal interstitial fibrosis.

MicroRNA-497 and bufalin act synergistically to inhibit colorectal cancer metastasis.

The study aims to investigate the effect of microRNA-497 (miR-497) expression and bufalin treatment in regulating colorectal cancer invasion and metastasis. The expression of miR-497 in colorectal cancer cells with prior treatment with bufalin was determined using real-time quantitative PCR. The nude mouse abdominal aortic ring assay and the human umbilical vein endothelial cell (HUVEC) migration assays were used to measure the angiogenic effect of bufalin. The effect of both bufalin treatment and miR-497 overexpression on colorectal cancer metastasis was measured using an animal tumor model together with in vivo imaging. These results suggested: (1) In the HCT116 cells and HUVECs, proliferation was inhibited in a time-dependent and/or concentration-dependent manner following the administration of bufalin; (2) Bufalin inhibited cell migration in a concentration-dependent manner by cell motility assays; (3) In the aortic ring assay, administration bufalin to the aortic ring significantly promoted micro-angiogenesis of nude mouse abdominal aorta in a concentration-dependent and time-dependent manner; (4) miR-497 was upregulated in human colorectal cancer HCT116 cells treated with different concentrations of bufalin in a concentration-dependent manner; and (5) Combined application of bufalin and miR-497 significantly reduced metastatic lesions and reduced weight loss compared with bufalin alone and control groups in vivo. This study revealed that bufalin inhibited angiogenesis and regulated miR-497 expression and that bufalin and miR-497 acted in synergy to inhibit colorectal cancer metastasis, resulting in improved quality of life in a nude mouse model.

The effect of acupuncture on gastrointestinal recovery after abdominal surgery: a narrative review from clinical trials.

Abdominal surgery is a critical surgery, with more and more attention being paid to postoperative life quality and associated complications in recent years. Among these complications, postoperative gastrointestinal dysfunction is the most common complication of abdominal surgery. Acupuncture therapy is a treatment approach based on the Traditional Chinese Medicine theory, and its feasibility in aiding gastrointestinal recovery after abdominal surgery is supported by both Traditional Chinese Medicine theory and animal experiments. A lot of clinical research has been conducted to evaluate its efficacy, albeit with limitations, and at preliminary stages. Moreover, intervention timing, acupoint selection, and patient benefits should also be considered in clinical practices. This article summarizes the progress of clinical research on acupuncture therapy in gastrointestinal recovery after abdominal surgery and discusses related issues and operations, with the aim to provide new insights and prospects for the incorporation of acupuncture into the Enhanced Recovery After Surgery protocol.

Electroacupuncture improves survival in rats with lethal endotoxemia via the autonomic nervous system.

BACKGROUND: Recent advances have indicated a complex interplay between the autonomic nervous system and the innate immune system. Targeting neural networks for the treatment of sepsis is being developed as a therapeutic strategy. Because electroacupuncture at select acupoints can modulate activities of the autonomic nervous system, we tested the hypothesis that electroacupuncture at specific acupoints could modulate systemic inflammatory responses and improve survival via its impact on the autonomic nervous system in a rat model of sepsis. METHODS: Sprague-Dawley male rats received electroacupuncture for 45 min before and at 1, 2, or 4 h after a lethal dose of intraperitoneal lipopolysaccharide injection (6 mg/kg). Outcomes included survival and systemic cytokine responses. Also, the possible roles of neural circuitry, including the hypothalamic-pituitary-adrenal axis and the autonomic nervous system, were evaluated. RESULTS: Electroacupuncture pretreatment at the Hegu acupoints significantly attenuate systemic inflammatory responses and improve survival rate from 20% to 80% in rats with lethal endotoxemia. Such a site-specific effect requires the activation of muscarinic receptors in the central nervous system, but not increasing central sympathetic tone. In the periphery synergistic, rather than independent, action of the sympathetic and parasympathetic systems is also necessary. CONCLUSIONS: Electroacupuncture pretreatment has a dramatic survival-enhancing effect in rats with lethal endotoxemia, which involves the activation of efferent neural circuits of the autonomic nervous system (e.g., cholinergic antiinflammatory pathway). This approach could be developed as a prophylactic treatment for sepsis or perioperative conditions related to excessive inflammation.

Candidate metabolite markers of peripheral neuropathy in Chinese patients with type 2 diabetes.

OBJECTIVES: To analyze the serum and urine metabolites present in type 2 diabetes mellitus (T2DM) patients and T2DM patients with diabetic peripheral neuropathy (DPN) and to select differentially expressed biomarkers for early diagnosis of DPN. METHODS: Serum and urine metabolites from 74 T2DM patients with peripheral neuropathy and 41 without peripheral neuropathy were analyzed using gas chromatograph system with time-of-flight mass spectrometer metabolomics to detect biomarkers of peripheral neuropathy in T2DM. RESULTS: There were increased serum triglycerides, alanine aminotransferase, and decreased C-peptide, and total cholesterol levels in T2DM patients with DPN compared to those without peripheral neuropathy. Metabolomic analysis revealed visible differences in metabolic characteristics between two groups, and overall 53 serum differential metabolites and 56 urine differential metabolites were identified with variable influence on projection (VIP) >1 and P<0.05. To further analyze the correlation between the identified metabolites and DPN, four serum metabolites and six urine metabolites were selected with VIP>2, and fold change (FC) >1, including serum ß-alanine, caproic acid, ß-alanine/L-aspartic acid, and L-arabinose/L-arabitol, and urine gluconic acid, erythritol, galactonic acid, guanidoacetic acid, cytidine, and aminoadipic acid. Furthermore, five serum biomarkers and six urine biomarkers were found to show significant changes (P<0.05, VIP>1, and FC>1) respectively in patients with mild, moderate, and severe DPN. In addition, we found that glyoxylate and dicarboxylate metabolism was a differential metabolic pathway not only between T2DM and DPN, but also among different degrees of DPN. The differential metabolites such as ß-alanine and caproic acid are expected to be biomarkers for DPN patients, and the significant changes in glyoxylate and dicarboxylate metabolism may be related to the pathogenesis of DPN. CONCLUSION: There were serum and urine spectrum metabolomic differences in patients with DPN, which could serve as biomarkers for T2DM and DPN patients.

[Effect of jianpi jiedu recipe on microvessel density and cyclooxygenase-2 expression in Heliobacter pylori induced gastric cancer].

OBJECTIVE: To investigate the regulatory effect of jianpi jiedu Recipe (JJR) on the microvessel density (MVD) and cyclooxygenase-2 (COX-2) in long-term infection of Helicobacter pylori induced gastric cancer of C57BL/6 mice, thus providing experimental bases for its treatment of the H. pylori correlated gastropathy. METHODS: C57BL/6 mouse gastric cancer model induced by H. pylori infection was established by gastrogavage of H. pylori standard strain SS1. Mice were divided into the control group, the model group, low dose JJR group, and the high dose JJR group, 40 in each group. Mice were sacrificed after 72-week medication. Changes of the gastric mucosa MVD of mice in each group were detected by immunohistochemical method. Expressions of COX-2 mRNA and protein were detected by Real-time fluorescent quantitative polymerase chain reaction and immunohistochemical method. RESULTS: The occurrence rate of gastric cancer in the control group, the model group, the low dose JJR group, and the high dose JJR group was 0, 22.2%, 11.1%, and 10.0%, respectively. The gastric mucosa MVD (number/cm2) of mice in each group was 2.50 +/- 1.54, 18.56 +/- 2.62, 14.61 +/- 3.60, and 7.39 +/- 1.75, respectively. The gastric mucosa MVD in the model group increased more obviously than that in the control group (P < 0.01). The gastric mucosa MVD significantly decreased in the low dose JJR group and the high dose JJR group (P < 0.01). Expressions of COX-2 mRNA and protein in the model group increased more obviously than those in the control group (P < 0.01). Low dose JJR and high dose JJR could decrease their expressions in a dose dependent manner. CONCLUSIONS: H. pylori infection could increase the gastric mucosa MVD of C57BL/6 mice and promote COX-2 expressions, which might play a promoting effect in the incidence of H. pylori induced gastric cancer. JJR could decrease the gastric mucosa MVD and inhibit COX-2 expressions, which might be one of its important mechanisms of preventing and treating gastric cancer.

The Anti-Tumor Effect and Mechanism of Triterpenoids in Rhus chinensis Mill. on Reversing Effector CD8+ T-cells Dysfunction by Targeting Glycolysis Pathways in Colorectal Cancer.

Rhus chinensis Mill. is a traditional Chinese medicine (TCM) which is commonly used for cancer treatments. Our previous work had proven that triterpenoids of Rhus chinensis (TER) could effectively regulate glycolysis involved in colorectal cancer (CRC) and play an important role in the prevention of T-cells dysfunction. This study aimed to systematically investigate the effects and mechanisms of TER on glucose metabolism in CRC, while the regulatory mechanisms of TER on restoring T-cells function and activity in CRC were explored as well. The extract of triterpenoids from Rhus chinensis was obtained, and production of lactic acid and glucose uptake were assayed. Also, the expression of CD8+ T-cells surface markers, cytokines secreted by CD8+ T cells, and the expression of key glycolytic enzymes and glucose deprivation induced by tumor cells were further examined. Notably, results showed that TER prevented the dysfunction in CD8+ T cells by enhancing mTOR activity and subsequent cellular metabolism. Furthermore, our findings also demonstrated that TER promoted glycolytic gene expression in CD8+ T cells in vivo, and significantly inhibited tumor growth. Altogether, our studies suggested that TER not only reversed effector CD8+ T-cells dysfunction and enhanced T-cells recognition, but also improved tumor microenvironment, thereby providing new insight into the prevention and treatment of CRC with TCM.

PGE2-JNK signaling axis non-canonically promotes Gli activation by protecting Gli2 from ubiquitin-proteasomal degradation.

Both bench and bedside investigations have challenged the supportive role of Hedgehog (Hh) activity in the progression of colorectal cancers, thus raising a critical need to further deeply determine the contribution of Hh to the growth of colorectal cancer. Combining multiple complementary means, including in vitro and in vivo inflammatory colorectal cancer models, and pathological analysis of clinical colorectal cancer patients samples. We report that colorectal cancer cells hijack prostaglandin E2 (PGE2) to non-canonically promote Hh transcriptional factor Gli activity and Gli-dependent proliferation of colorectal cancer cells in a Smo-independent manner. Mechanistically, PGE2 activates c-Jun N-terminal kinase (JNK), which in turn enables Gli2 to evade ubiquitin-proteasomal degradation by phosphorylating Gli2 at Thr1546. This study not only presents evidence for understanding the contribution of Hh to colorectal cancers, but also provides a novel molecular portrait underlying how PGE2-activated JNK fine-tunes the evasion of Gli2 from ubiquitin-proteasomal degradation. Therefore, it proposes a rationale for the future evaluation of chemopreventive and selective therapeutic strategies for colorectal cancers by targeting PGE2-JNK-Gli signaling route.

The effects and mechanisms of isoliquiritigenin loaded nanoliposomes regulated AMPK/mTOR mediated glycolysis in colorectal cancer.

In this study, isoliquiritigenin (ISL) incorporated nanoliposomes were prepared and their effects on colorectal cancer (CRC) cell lines were investigated. Herein, we sought to explore the anti-cancer mechanisms of ISL loaded nanoliposomes (ISL-NLs) on AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathways mediated glycolysis. Also, the key targets such as caveolin 1 (CAV1), glucose transporters and Akt/mTOR that promote glycolysis, and are activated via the induction of α-enolase (ENO1), fructose bisphosphate aldolase A (ALDOA) and monocarboxylate transporter 4 (MCT4) expressions were also investigated. It was shown that ISL-NLs significantly suppressed the proliferation and glucose uptake of CRC cell by potentially regulating the glycolysis and lactate targets as well as pathways that formed the basis of the anti-CRC effects of ISL-NLs. The mechanism underlying this effect was further validated via the regulation of some key targets such as ENO1, ALDOA, lactate dehydrogenase A (LDHA) and MCT4 in glycolysis coupled with cellular myelocytomatosis oncogene (c-myc), hypoxia-inducible factor 1-alpha (HIF-1α) in protein kinase B/mTOR (Akt/mTOR) pathways. Moreover, the AMPK proteins were identified to be up-regulated while the lactic acid production was suppressed by ISL-NLs in the CRC cells, indicating that ISL-NLs had an inhibitory effect on AMPK mediated glycolysis and lactate production. Altogether, these results have provided insights into the mechanism underlying the key role that liposomal ISL played in the multiple inhibition of AMPK and Akt/mTOR mediated glycolysis and lactate generation, which may be regulated as the alternative metabolic pathways of CRC as well as serve as adjuvant therapy for the disease.

The Antitumor Activity of Betulinic Acid-Loaded Nanoliposomes Against Colorectal Cancer In Vitro and In Vivo via Glycolytic and Glutaminolytic Pathways.

The purpose of this study is to develop betulinic acid loaded nanoliposomes to improve the chemotherapy effect of colorectal cancer. The cellular uptake and anti-tumor effects of betulinic acid loaded nanoliposomes in vitro were characterized and evaluated, and their effects on glycolysis, glutamine decomposition and key anti-cancer targets were analyzed. Moreover, their anticancer efficacy was assessed in vivo. Compared with free betulinic acid in vitro, the cellular uptake and anti-tumor activity of betulinic acid-loaded nanoliposomes were significantly enhanced; these nanoliposomes significantly suppressed the proliferation and glucose uptake of colorectal cancer cells. Mechanistically, the anti-colorectal cancer effect of betulinic acid-loaded nanoliposomes was confirmed by their triggering of cellular apoptosis and regulating the potential glycolytic and glutaminolytic targets and pathways. After tumor proliferation was inhibited and colorectal cancer cells apoptosis, the anticancer effect of betulinic acid loaded nanoliposomes in vivo was significantly enhanced. All in all, betulinic acid loaded nanoliposomes are expected to be an effective drug delivery system for colorectal cancer treatment.

Effects and mechanisms of fatty acid metabolism­mediated glycolysis regulated by betulinic acid­loaded nanoliposomes in colorectal cancer.

Although previous studies have demonstrated that triterpenoids, such as betulinic acid (BA), can inhibit tumor cell growth, their potential targets in colorectal cancer (CRC) metabolism have not been systematically investigated. In the present study, BA­loaded nanoliposomes (BA­NLs) were prepared, and their effects on CRC cell lines were evaluated. The aim of the present study was to determine the anticancer mechanisms of action of BA­NLs in fatty acid metabolism­mediated glycolysis, and investigate the role of key targets, such as acyl­CoA synthetase (ACSL), carnitine palmitoyltransferase (CPT) and acetyl CoA, in promoting glycolysis, which is activated by inducing hexokinase (HK), phosphofructokinase­1 (PFK­1), phosphoenolpyruvate (PEP) and pyruvate kinase (PK) expression. The results demonstrated that BA­NLs significantly suppressed the proliferation and glucose uptake of CRC cells by regulating potential glycolysis and fatty acid metabolism targets and pathways, which forms the basis of the anti­CRC function of BA­NLs. Moreover, the effects of BA­NLs were further validated by demonstrating that the key targets of HK2, PFK­1, PEP and PK isoenzyme M2 (PKM2) in glycolysis, and of ACSL1, CPT1a and PEP in fatty acid metabolism, were blocked by BA­NLs, which play key roles in the inhibition of glycolysis and fatty acid­mediated production of pyruvate and lactate. The results of the present study may provide a deeper understanding supporting the hypothesis that liposomal BA may regulate alternative metabolic pathways implicated in CRC adjuvant therapy.

Increasing the anticancer performance of bufalin (BUF) by introducing an endosome-escaping polymer and tumor-targeting peptide in the design of a polymeric prodrug.

A well-defined multifunctional brush-type polymeric prodrug covalently linked with an anticancer drug (bufalin, BUF), a tumor-targeting peptide (RGD), and an endosome-escaping polymer, poly(N,N-diethylaminoethyl methacrylate-co-butyl methacrylate (P(DEA-co-BMA)), was developed. Its anticancer performance against colon cancer was investigated in vitro and in vivo. Reversible addition-fragmentation transfer (RAFT) polymerization of oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA), 2-((3-(tert-butoxy)-3-oxopropyl)thio)ethyl methacrylate (BSTMA), and 2-(2-bromoisobutyryloxy)ethylmethacrylate (BIEM) afforded the multifunctional random copolymer, P(OEGMA-co-BSTMA-co-BIEM), in which hydrophilic POEGMA can stabilize nanoparticles in water, PBSTMA can be converted into carboxyl groups, and PBIEM can be employed as a macromolecular atom radical transfer polymerization (ATRP) initiator. The ATRP of DEA and BMA using P(OEGMA-co-BSTMA-co-BIEM) as a macromolecular ATRP initiator led to the formation of the pH-responsive brush-type copolymer, P(OEGMA-co-BSTMA)-g-P(DEA-co- BMA). After hydrolysis by trifluoroacetic acid and post-functionalization the final polymeric prodrug, P(OEGMA-co-BUF-co-RGD)-g-P(DEA-co-BMA), was obtained with a drug content of ∼7.8 wt%. P(OEGMA-co-BUF-co-RGD)-g-P(DEA-co-BMA) can be assembled into nanoparticles (BUF- NP-RGD) in aqueous solution with a diameter of 148.4 ±â€¯0.7 nm and a zeta potential of -7.6 ±â€¯0.4 mV. BUF-NP-RGD exhibited controlled drug release in the presence of esterase. Additionally, P(OEGMA-co- BSMA)-g-P(DEA-co-BMA) showed a significant hemolysis effect at a pH comparable to that of endosomes/lysosomes. Cell viability and a tumor-bearing nude mouse model were employed to evaluate the anticancer efficacy of BUF-NP-RGD. It was revealed that BUF-NP-RGD showed improved anticancer performance compared with that of free BUF both in vitro and in vivo. Histological and immunochemical analysis further demonstrated that BUF-NP-RGD exhibited improved cell apoptosis, angiogenesis inhibition, and an anti-proliferation effect.

Protective effects of probucol on Ox-LDL-induced epithelial-mesenchymal transition in human renal proximal tubular epithelial cells via LOX­1/ROS/MAPK signaling.

Oxidized low-density lipoprotein (Ox-LDL), as a strong oxidant, results in renal injury through multiple mechanisms. The aim of the present study was to determine the injury effects of Ox­LDL and the potential protective effects of the antioxidant reagent probucol on epithelial­mesenchymal transition (EMT) in human renal proximal tubular epithelial cells (HK­2) and to further explore the role and interrelation of lectin­like oxidized low­density lipoprotein receptor­1 (LOX­1), reactive oxygen species (ROS) and mitogen­activated protein kinase (MAPK) pathway. In the present study, concentrations of 0­100 µg/ml Ox­LDL were used to induce HK­2 cell EMT. Then, probucol (20 µmol/l) and the LOX­1 inhibitor, polyinosinic acid (250 µg/ml), were also used to pretreat HK­2 cells. Intracellular ROS activity was evaluated using the specific probe 2',7'­dichlorodihydrofluorescein diacetate (DCFH­DA). Concentration of nitric oxide (NO) was determined using a biochemical colorimetric method. Expression of E­cadherin, α­smooth muscle actin (SMA), LOX­1, NADPH oxidase 4 (NOX4), cytochrome b­245 α chain (p22phox), extracellular signal­regulated kinase (ERK), and p38 MAPK protein levels were examined by western blotting. The results revealed that Ox­LDL induced the expression of LOX­1 and α­SMA and reduced the expression of E­cadherin in a dose­dependent manner, and these effects were inhibited by polyinosinic acid or probucol pretreatment. Stimulation with 50 µg/ml Ox­LDL induced the expression of NOX4 and p22phox and increased intracellular ROS activity, but NO production in the cell supernatants was not affected. The Ox­LDL­mediated increases in Nox4 and p22phox expression and in ROS activity were inhibited by probucol pretreatment. Further investigations into the underlying molecular pathways demonstrated that ERK and p38 MAPK were activated by Ox­LDL stimulation and then inhibited by probucol pretreatment. The findings of the present study therefore suggest that Ox­LDL induced EMT in HK­2 cells, the mechanism of which may be associated with LOX­1­related oxidative stress via the ERK and p38 MAPK pathways. Notably, pretreatment with probucol inhibited the Ox­LDL­induced oxidative stress by reducing the expression of LOX­1, and blocked the progression of EMT.