Mechanism of Cations Suppressing Proton Diffusion Kinetics for Electrocatalysis.

Proton transfer is crucial for electrocatalysis. Accumulating cations at electrochemical interfaces can alter the proton transfer rate and then tune electrocatalytic performance. However, the mechanism for regulating proton transfer remains ambiguous. Here, we quantify the cation effect on proton diffusion in solution by hydrogen evolution on microelectrodes, revealing the rate can be suppressed by more than 10 times. Different from the prevalent opinions that proton transport is slowed down by modified electric field, we found water structure imposes a more evident effect on kinetics. FTIR test and path integral molecular dynamics simulation indicate that proton prefers to wander within the hydration shell of cations rather than to hop rapidly along water wires. Low connectivity of water networks disrupted by cations corrupts the fast-moving path in bulk water. This study highlights the promising way for regulating proton kinetics via a modified water structure.

Efficacy and Safety of Huashi Baidu Granules in Treating Patients with SARS-CoV-2 Omicron Variant: A Single-Center Retrospective Cohort Study / 中国结合医学杂志

OBJECTIVE@#To evaluate the efficacy and safety of Huashi Baidu Granules (HSBD) in treating patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant.@*METHODS@#A single-center retrospective cohort study was conducted during COVID-19 Omicron epidemic in the Mobile Cabin Hospital of Shanghai New International Expo Center from April 1st to May 23rd, 2022. All COVID-19 patients with asymptomatic or mild infection were assigned to the treatment group (HSBD users) and the control group (non-HSBD users). After propensity score matching in a 1:1 ratio, 496 HSBD users of treatment group were matched by propensity score to 496 non-HSBD users. Patients in the treatment group were administrated HSBD (5 g/bag) orally for 1 bag twice a day for 7 consecutive days. Patients in the control group received standard care and routine treatment. The primary outcomes were the negative conversion time of nucleic acid and negative conversion rate at day 7. Secondary outcomes included the hospitalized days, the time of the first nucleic acid negative conversion, and new-onset symptoms in asymptomatic patients. Adverse events (AEs) that occurred during the study were recorded. Further subgroup analysis was conducted in vaccinated (378 HSBD users and 390 non-HSBD users) and unvaccinated patients (118 HSBD users and 106 non-HSBD users).@*RESULTS@#The median negative conversion time of nucleic acid in the treatment group was significantly shortened than the control group [3 days (IQR: 2-5 days) vs. 5 days (IQR: 4-6 days); P<0.01]. The negative conversion rate of nucleic acid in the treatment group were significantly higher than those in the control group at day 7 (91.73% vs. 86.90%, P=0.014). Compared with the control group, the hospitalized days in the treatment group were significantly reduced [10 days (IQR: 8-11 days) vs. 11 days (IQR: 10.25-12 days); P<0.01]. The time of the first nucleic acid negative conversion had significant differences between the treatment and control groups [3 days (IQR: 2-4 days) vs. 5 days (IQR: 4-6 days); P<0.01]. The incidence of new-onset symptoms including cough, pharyngalgia, expectoration and fever in the treatment group were lower than the control group (P<0.05 or P<0.01). In the vaccinated patients, the median negative conversion time and hospitalized days were significantly shorter than the control group after HSDB treatment [3 days (IQR: 2-5 days) vs. 5 days (IQR: 4-6 days), P<0.01; 10 days (IQR: 8-11 days) vs. 11 days (IQR: 10-12 days), P<0.01]. In the unvaccinated patients, HSBD treatment efficiently shorten the median negative conversion time and hospitalized days [4 days (IQR: 2-6 days) vs. 5 days (IQR: 4-7 days), P<0.01; 10.5 days (IQR: 8.75-11 days) vs. 11.0 days (IQR: 10.75-13 days); P<0.01]. No serious AEs were reported during the study.@*CONCLUSION@#HSBD treatment significantly shortened the negative conversion time of nuclear acid, the length of hospitalization, and the time of the first nucleic acid negative conversion in patients infected with SARS-COV-2 Omicron variant (Trial registry No. ChiCTR2200060472).

Pre-expanded muscle-sparing Latissimus Dorsi free flap: An ideal option for the reconstruction of extensive anterior knee contractures.

BACKGROUND: Extensive and complex contractures in the anterior knee area can pose a significant challenge for reconstruction due to insufficient skin and soft tissue coverage and poor cosmetic and functional outcomes using traditional methods. We presented our experience with pre-expanded muscle-sparing latissimus dorsi (LD) free flap as an alternative option for large-scale anterior knee reconstruction. METHODS: From January 2016 to December 2020, we applied this surgical technique in six patients with large postburn or post-traumatic contractures of the anterior knee. After tissue expansion of several months, the expanded muscle-sparing LD free flap was harvested and transferred to resurface the lesions. Operative procedures, postoperative complications, and long-term outcomes were evaluated. RESULTS: A total of six patients aged 7 to 32 years (mean: 20 years) were reconstructed successfully without any major complication. The flap ranged from 20 × 8 cm to 40 × 16 cm. All donor sites were primarily closed. Follow-up (range: 12 to 24 months) evaluation showed satisfactory results in both cosmetic and functional aspects. CONCLUSIONS: Pre-expanded muscle-sparing LD free flap is a reliable and effective choice for extensive anterior knee contracture reconstruction with satisfactory esthetic and functional outcome. It can provide substantial amount of soft tissue coverage with minimal complications and donor-site morbidity. Furthermore, it offers a good basis for next-step orthopedic surgery, such as total knee arthroplasty (TKA).

PFKFB4 Overexpression Facilitates Proliferation by Promoting the G1/S Transition and Is Associated with a Poor Prognosis in Triple-Negative Breast Cancer.

BACKGROUND: 6-Phosphofructo-2-kinase/fructose-2,6-biphosphate-4 (PFKFB4) is a key factor that plays an important role in tumorigenesis. However, its role in triple-negative breast cancer (TNBC) progression needs to be further validated. We investigated whether PFKFB4 is directly involved in the oncogenic signaling networks of TNBC. METHODS: First, we assessed the expression level of PFKFB4 in tumor tissue specimens by immunohistochemistry and evaluated its prognostic value. Next, the effect of PFKFB4 on TNBC cell growth and associated mechanisms were investigated. Finally, the results were further verified in vivo. RESULTS: We found that PFKFB4 overexpression was associated with an unfavorable prognosis in TNBC patients. PFKFB4 was overexpressed in TNBC cell lines in hypoxic environments, and its overexpression promoted tumor progression in vitro and in vivo. Further analyses demonstrated that the possible mechanism might be that PFKFB4 overexpression facilitates TNBC progression by enhancing the G1/S phase transition by increasing the protein level of CDK6 and phosphorylation of Rb. CONCLUSIONS: These data suggest that PFKFB4 plays significant roles in the tumorigenesis and development of TNBC.

Nuclear isoform of FGF13 regulates post-natal neurogenesis in the hippocampus through an epigenomic mechanism.

The hippocampus is one of two niches in the mammalian brain with persistent neurogenesis into adulthood. The neurogenic capacity of hippocampal neural stem cells (NSCs) declines with age, but the molecular mechanisms of this process remain unknown. In this study, we find that fibroblast growth factor 13 (FGF13) is essential for the post-natal neurogenesis in mouse hippocampus, and FGF13 deficiency impairs learning and memory. In particular, we find that FGF13A, the nuclear isoform of FGF13, is involved in the maintenance of NSCs and the suppression of neuronal differentiation during post-natal hippocampal development. Furthermore, we find that FGF13A interacts with ARID1B, a unit of Brahma-associated factor chromatin remodeling complex, and suppresses the expression of neuron differentiation-associated genes through chromatin modification. Our results suggest that FGF13A is an important regulator for maintaining the self-renewal and neurogenic capacity of NSCs in post-natal hippocampus, revealing an epigenomic regulatory function of FGFs in neurogenesis.

ANGPTL4 overexpression inhibits tumor cell adhesion and migration and predicts favorable prognosis of triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) patients have relatively poor clinical outcomes. A marker predicting the prognosis of patients with TNBC could help guide treatment. Extensive evidence demonstrates that angiopoietin-like 4 (ANGPTL4) is involved in the regulation of cancer growth, metastasis and angiogenesis. Therefore, its role in TNBC is of interest. METHODS: We tested the ANGPTL4 expression level in tumor tissues by immunohistochemistry (IHC) and detected its association with the clinical features of TNBC patients. Next, the effects and mechanisms of ANGPTL4 on TNBC cell migration and adhesion were investigated. RESULTS: We found that ANGPTL4 overexpression was associated with favorable outcomes in TNBC patients. ANGPTL4 upregulation inhibited cell adhesion, migration and invasion in vitro. Further analyses demonstrated that the possible mechanism might involve suppression of TNBC progression by interacting with extracellular matrix-related genes. CONCLUSIONS: The present findings demonstrated that enhancement of ANGPTL4 expression might inversely correlate with TNBC progression. ANGPTL4 is a promising marker of TNBC and should be evaluated in further studies. TRIAL REGISTRATION: Retrospectively registered.

[Biogenesis, research methods, and functions of circular RNAs].

The field of circular non-coding RNAs have been gradually attracted wide attention with the developments of high-throughput sequencing. In this review, we systematically summarize three driving models for circRNAs biogenesis: intron-pairing-driven, RNA binding protein-driven and lariat-driven. In addition, we also briefly introduce the current research methods of circRNAs, which include high-throughput library construction methods, identification through bioinformatics and common experimental verification. Here, we also systematically summarize the functions of circRNAs, including microRNA (miRNA) or protein sponges, regulating the alternative splicing (AS) and expression of host genes, and extensive translation. Finally, we provide a systematic characterization and the latest research progress of circRNAs, which provide a new perspective for further studies of circRNAs in plants.

A novel Bcl-2 inhibitor, BM-1197, induces apoptosis in malignant lymphoma cells through the endogenous apoptotic pathway.

BACKGROUND: Bcl-2 family members play an important role in the development of malignant lymphoma and can induce drug resistance in anticancer treatment. The development of small molecules targeting Bcl-2 family proteins may be a new strategy for the treatment of malignant lymphoma. In this study, we investigate the antitumor effect and cellular mechanism of a novel Bcl-2/Bcl-xL dual inhibitor, BM-1197, in DCBCL and Burkitt lymphoma cells. METHODS: The CCK-8 assay was used to detect cell viability. Apoptosis was determined by Hoechst 33258 staining and flow cytometry. The activity of caspase-3/caspase-9 was determined using a caspase-3/caspase-9 activity kit. Western blotting analysis was performed to evaluate the changes in protein expression. Functional analysis was performed via immunoprecipitation and siRNA interference. Human malignant lymphoma xenograft models in nude mice were established for in vivo efficacy detection. RESULTS: We find that BM-1197 exerts potent growth-inhibitory activity against lymphoma cells that harbor high expression of Bcl-2 and Bcl-xL in vitro and has a synergistic effect with chemotherapeutic drugs. Mechanistically, we see that the intrinsic apoptosis pathway is activated upon BM-1197 treatment. BM-1197 affects the protein interactions of Bak/Bcl-xl, Bim/Bcl-2, Bim/Bcl-xl, and PUMA/Bcl-2 and induces conformational changes in the Bax protein, which result in the activation of Bax and release of cytochrome c, activate caspase - 9, - 3, and - 7 and finally induce cell apoptosis. Furthermore, our data demonstrate that BM-1197 exhibits strong anti-tumor effects against established human malignant lymphoma xenograft models. CONCLUSIONS: Our study demonstrated BM-1197 exerts potent antitumor effects both in vitro and in vivo and provides promising preclinical data for the further development of BM-1197 in malignant lymphoma.

Puquitinib mesylate (XC-302) induces autophagy via inhibiting the PI3K/AKT/mTOR signaling pathway in nasopharyngeal cancer cells.

There are numerous studies that demonstrate the anti-neoplastic activity of phosphatidylinositol 3-kinase (PI3K) inhibitors and the mechanisms of inducing autophagy in cancer cells. The new anticancer drug puquitinib mesylate (XC-302) is a molecular-targeted drug, which suppresses the activity of PI3K directly. However, it remains unclear whether XC­302 can develop an antitumor effect by inducing autophagy in nasopharyngeal cancer cells. The MTT assay was used to study the anti-proliferative effects of XC-302. Subsequently, autophagy was determined by monodansylcadaverine (MDC) staining, punctate localization of green fluorescent protein (GFP)-light chain 3 (LC3), LC3 protein blotting and electron microscopy. The expression levels of beclin 1, p62, protein kinase B (AKT), phospho (p)­AKT, mechanistic target of rapamycin (mTOR) and p­mTOR in XC-302­induced autophagy were detected. Autophagy inhibition was assayed by 3-methyladenine (3­MA) or small interfering RNA (siRNA) silencing of beclin 1. XC-302 inhibited the viability of CNE­2 in a dose-dependent manner and the IC50 of 72 h was 5.2 µmol/l. After cells were exposed to XC-302 for 24 h, MDC-labeled autophagolysosomes were evident in CNE-2 cells by fluorescence microscope. Autophagosomes and autolysosomes were identified by transmission electron microscopy. Following transfection with GFP­LC3, XC-302 induced a significant accumulation of GFP­LC3, as monitored by a confocal microscope, which was reduced by 3-MA. XC-302 induced the formation of LC3­II, increased beclin 1 levels and decreased the expression of p62. Additionally, the expression levels of p­AKT and p­mTOR were reduced with the elevation of XC-302. Knockdown of beclin 1 with siRNA or co-treatment with 3-MA enhanced significantly the survival of CNE-2 and promoted the ability of clone formation. XC-302 also induced apoptosis in CNE-2, and when autophagy was inhibited by 3-MA, the apoptosis rate was decreased. The present data provides the evidence that XC-302 can induce autophagy in CNE-2, which promotes the program of cell death and inhibits the PI3K/AKT/mTOR signaling pathway. Furthermore, XC-302 also promoted apoptosis in CNE-2 cells, which could be reduced when autophagy was suppressed, meaning that autophagy may interact with apoptosis to induce cell death.

The prognostic value of Tiam1 protein expression in head and neck squamous cell carcinoma: a retrospective study.

INTRODUCTION: Head and neck squamous cell carcinoma (HNSCC) is a common cancer worldwide and has a poor prognosis. A biomarker predicting the clinical outcome of HNSCC patients could be useful in guiding treatment planning. Overexpression of the T lymphoma invasion and metastasis 1 (Tiam1) protein has been implicated in the migration and invasion of neoplasms. However, its role in HNSCC progression needs to be further validated. We detected the expression of Tiam1 in normal and tumor tissues and determined its association with clinical outcomes in patients with HNSCC. METHODS: We measured the expression of Tiam1 in normal and cancerous tissue samples from the patients with HNSCC treated at Sun Yat-sen University Cancer Center between 2001 and 2008. The Tiam1 expression was scored from 0 to 12 based on the percentage of positively stained cells and the staining intensity. We then determined the diagnostic performance of this score in predicting overall survival (OS) and disease-free survival (DFS). RESULTS: Of the 194 evaluable patients, those with advanced disease, lymph node metastasis at diagnosis, and recurrence or metastasis during follow-up had a higher tendency of having high Tiam1 expression as compared with their counterparts (P < 0.05). The proportion of samples with high Tiam1 expression was also higher in cancerous tissues than in non-cancerous tissues (57.7% vs. 13.9%, P < 0.001). Cox proportional hazards regression analysis revealed that Tiam1 expression scores of 5 and greater independently predicted short OS and DFS. CONCLUSION: The Tiam1 expression is shown as a promising biomarker of clinical outcomes in patients with HNSCC and should be evaluated in prospective trials.

Comparison of five cisplatin-based regimens frequently used as the first-line protocols in metastatic nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: No randomized trial has been reported comparing different chemotherapy regimens on disseminated nasopharyngeal carcinoma (NPC). This study aims to compare five cisplatin-based regimens including cisplatin + 5-fluororacil (PF), paclitaxel + cisplatin (TP), gemcitabine + cisplain (GP), paclitaxel + cisplatin + 5-fluororacil (TPF), and bleomycin + cisplatin + 5-fluororacil (BPF) regimen most frequently used as the first-line protocols for metastatic NPC retrospectively. METHODS: Eight hundred and twenty-two patients with metastatic NPC were divided into five groups according to the regimen they received. Then, their response rate, toxicity, and long-term survival outcome as well as the prognostic factors were analyzed. RESULTS: The higher response rates in GP and TPF regimens comparing to PF regimen were achieved (Χ (2) = 4.57, P = 0.033; Χ (2) = 7.04, P = 0.008), as well as in TPF regimen comparing to TP regimen (Χ (2) = 5.579, P = 0.018). The occurrence rate of the major III-IV grade toxicity was significantly different between the five groups. However, no statistically significant difference was observed in progression-free survival (PFS; P = 0.247) and overall survival (P = 0.127) among the five groups. Cox multivariate analysis identified the following independent prognostic factors: liver metastases, plasma Epstein Barr Virus (EBV)-DNA level, cycles of chemotherapy, and second-line chemotherapy. CONCLUSIONS: PF, TP, and GP are all effective regimens as the first-line chemotherapy for metastatic NPC, which can be well tolerated. Over four cycles of chemotherapy are recommended under no contraindication. Patients should transfer to the second-line regimen after the treatment failure of the first-line chemotherapy.

Expression of ERCC1 predicts clinical outcome in locoregionally advanced nasopharyngeal carcinoma treated with cisplatin-based induction chemotherapy.

The aim of the present study was to evaluate the correlation between excision repair cross-complementation group 1 (ERCC1) protein with the clinical outcome of nasopharyngeal carcinoma (NPC) patients treated with cisplatin-based induction chemotherapy. One hundred one Stage III-IVB nonkeratinizing NPC patients who were treated with cisplatin (DDP)+fluorouracil (5-Fu) induction chemotherapy were recruited. Pre-treatment tumor biopsy specimens were analyzed for ERCC1 by immunohistochemistry. The relationship of ERCC1 expression and chemotherapy response and survival of these NPC patients was analyzed. The objective response to induction chemotherapy of NPC patients with low ERCC1 expression compared with high ERCC1 expression was 88.2% vs. 72% (P=0.041). The 5-year distant failure-free survival (D-FFS) of NPC patients with low ERCC1 expression compared with high ERCC1 expression was 73.5% vs. 51.3% (P=0.037). ERCC1 expression was a significant prognostic factor for overall survival and D-FFS using Cox regression analysis. High tumor ERCC1 expression predicts low chemotherapy response and poor survival mainly caused by more metastasis in locoregionally advanced NPC treated with cisplatin-based induction chemotherapy.

Serum C-reactive protein as an important prognostic variable in patients with diffuse large B cell lymphoma.

C-reactive protein (CRP) is an acute-phase reactant that is a promising biomarker in patients with cancer of many kinds. The aim of this retrospective study was to evaluate significant changes in CRP levels as a parameter for the response effect and long-term survival of patients with diffuse large B cell lymphoma (DLBCL). Serum CRP data were collected in 94 patients with DLBCL from October 2006 to August 2009 in Cancer Center, Sun Yat-Sen University. Results were correlated with clinical data. The median CRP serum level in patients with DLBCL was 30.91 ± 53.35 in male and 22.39 ± 29.89 mg/L in female. Base line CRP levels were correlated with International Prognostic Index (IPI) scores (p = 0.03). Among the patients with an IPI score of 1-2, base line CRP levels were correlated with long-term survival (p = 0.001). Base line CRP levels were also correlated with OS (p = 0.001) and varied with different clinical stages (p = 0.03). The corresponding CRP levels in the patients with 2 cycles of chemotherapy were correlated with short-term treatment response (p = 0.003) and OS (p = 0.04) or TTP (p = 0.03). CRP serum levels can be used as additional prognostic parameter in patients with diffuse large B cell type lymphoma.

Radiofrequency ablation combined with systemic chemotherapy in nasopharyngeal carcinoma liver metastases improves response to treatment and survival outcomes.

BACKGROUND: Systemic chemotherapy is the major treatment modality for nasopharyngeal carcinoma (NPC) liver metastases. We investigated the effectiveness of radiofrequency ablation (RFA) treatment, which has not been well explored in this disease. METHODS: One-hundred and thirty-four cases of NPC with liver metastases treated with chemotherapy, chemotherapy with RFA, or RFA alone were retrospectively analyzed. Patient survival was evaluated by the log-rank test. Survival was analyses using the Kaplan-Meier method. Cox multivariate analyses of clinicopathological features and different treatment approaches were conducted. RESULTS: Local response rates were 58% in the RFA group, 78% in the chemotherapy group and 93% in the chemotherapy with RFA group (P < 0.001). Increased progression-free survival (PFS) and overall survival (OS) were observed in the chemotherapy with RFA group (P < 0.001). Cox multivariate analysis indicated that the number of liver metastases (1 vs. >1), the dimension of the largest liver metastases (≤3 cm vs. >3 cm), evaluation of treatment (response vs. no response) and disease-free survival (≤12 months vs. >12 months) were independent prognostic factors. CONCLUSIONS: RFA combined with chemotherapy is a promising treatment for NPC metastatic liver disease with improved local response, PFS, and OS compared to current chemotherapy protocols.

Autophagy-related proteins Beclin-1 and LC3 predict cetuximab efficacy in advanced colorectal cancer.

AIM: To investigate the utility of Beclin-1 and LC3, two autophagy-related proteins, in predicting the cetuximab efficacy in advanced colorectal cancer (ACRC). METHODS: The data of 85 patients with ACRC treated at the Sun Yat-sen University Cancer Center from March 1, 2005 to December 31, 2008 were studied, including 45 cases treated with cetuximab-containing chemotherapy and 40 cases treated with non-cetuximab-containing chemotherapy. Beclin-1 and LC3 expression was evaluated by immunohistochemistry, and KRAS status was evaluated by polymerase chain reaction. RESULTS: Beclin-1 and LC3 expression in ACRC was significantly correlated (r = 0.44, P < 0.01); however, LC3 was more highly expressed in cancerous tissues than in normal tissues (Z = -2.63, P < 0.01). In the cetuximab-containing chemotherapy group, patients with low LC3 expression had higher objective response rates (ORRs) than those with high LC3 expression (52.9% vs 17.9%, P = 0.01), and patients with low Beclin-1 expression had a longer median progression-free survival (PFS) than their counterparts with higher Beclin-1 expression (9.0 mo vs 3.0 mo, P = 0.01). However, neither of these predictive relationships was detected in the group treated with non-cetuximab-containing chemotherapy. Patients with wild-type KRAS had higher ORRs (42.3% vs 9.1%, P = 0.049) and disease control rates (DCRs) (73.1% vs 36.4%, P = 0.035), and longer median PFS (5.5 mo vs 2.5 mo, P = 0.02) than those with mutant KRAS in the cetuximab-containing chemotherapy group. Neither Beclin-1 (P = 0.52) nor LC3 (P = 0.32) expression was significantly correlated with KRAS status. CONCLUSION: Patients with low Beclin-1 expression had a longer PFS than those with high Beclin-1 expression, and patients with low LC3 expression had a higher ORR in ACRC patients treated with cetuximab-containing chemotherapy.

Zoledronic acid combined with chemotherapy bring survival benefits to patients with bone metastases from nasopharyngeal carcinoma.

PURPOSE: Bone is the most common site of metastases from nasopharyngeal carcinoma (NPC). Zoledronic acid (ZA) used to prevent skeletal-related events (SREs) of bone metastases has shown anti-tumor effects; yet, no report has been found on the survival benefit of ZA in NPC. This study aimed to evaluate whether ZA can bring survival benefits to patients with bone metastases from NPC. METHODS: A total of 307 patients with of NPC who had bone metastases were analyzed retrospectively. The differences of survival between patients treated with chemotherapy combined with ZA and those with chemotherapy alone were evaluated by the log-rank test. The Cox multivariate analyses of clinical features and different treatment methods of the 307 patients were conducted. RESULTS: The prevalence of SREs in the combined approach group was lower than that with chemotherapy alone (34% vs. 48%, X (2) = 7.003, P = 0.008). The combined approach group had better progression-free survival (PFS) (11.5 vs. 5.5 months, P < 0.001) and overall survival (OS) (23.5 vs. 17.5 months, P < 0.001) than chemotherapy alone group. Cox multivariate analysis identified the following independent prognostic factors: ZA treatment, bone metastatic sites, baseline serum alkaline phosphatase (ALP) level, SREs and cycles of chemotherapy. CONCLUSIONS: ZA treatment combined with chemotherapy could reduce SREs and improve PFS and OS for NPC patients with bone metastases.

Anti-tumor activity and mechanisms of a novel vascular disrupting agent, (Z)-3,4',5-trimethoxylstilbene-3'-O-phosphate disodium (M410).

Vascular disrupting agents (VDAs) have emerged as a new kind of anti-cancer drug in recent years. Structural modification of an active parent compound is an effective approach to developing new agents with more activity and fewer adverse reactions. In our study, six synthesized stilbene derivatives were screened for their cytotoxic activity against human tumor cells, and their mechanisms of action were investigated. The MTT assay was used to determine the anti-proliferative activity of these compounds. Polymerization of tubulin was detected by a tubulin assembly assay, and the cellular microtubule network was observed by immunocytochemical analyses. Cell-cycle distribution was detected by flow cytometry. A nude mouse model with xenografted colon cancer was used to demonstrate the in vivo anti-tumor activity, and microvessel density (MVD) was determined by immunohistochemistry. The expression levels of protein and mRNA were detected by Western blot and RT-PCR, respectively. Among the six newly synthesized compounds, (Z)-3,4',5-trimethoxylstilbene-3'-O-phosphate disodium (M410) showed potent cytotoxic activity toward proliferating tumor cells and exhibited a similar cytotoxicity against multi-drug resistant (MDR) tumor cells. M410 inhibited bovine brain tubulin polymerization in a way similar to that of colchicine. In proliferating human umbilical vein endothelial cells (HUVECs), 20 nM of M410 induced cellular tubulin depolymerization within 4 h, which led to M phase arrest. Systemic administration of M410 at nontoxic doses in nude mice resulted in inhibition of tumor growth of human colon cancer LoVo xenografts. The tumor vessel density also decreased after M410 treatment, as determined by immunohistochemical staining for CD31. M410 downregulated hypoxia-inducible factor-1 alpha (HIF-1α) expression, reduced nuclear HIF-1α, and downregulated vascular endothelial cell growth factor (VEGF) mRNA. Our results indicate that M410 is a potent microtubule inhibitor that is cytotoxic, angiogenesis inhibiting and vascular targeting.

Anti-tumour effects of xanthone derivatives and the possible mechanisms of action.

To explore the potential anti-tumour activities of xanthone derivatives, 26 hydroxylxanthones and benzoxanthones and their structurally modified analogues were examined for potential cytotoxic activities against eight human cancer cell lines. Most of the xanthone derivatives exhibited a higher degree of cytotoxicity on HepG2 cells than on the other seven cancer cell lines. Compound 24 (1,3,7-Trihydroxy-12H-benzo[b] xanthen-12-one) showed the highest degree of cytotoxicity of the tested compounds against HepG2 cells and demonstrated good tumour specificity by exhibiting a much higher degree of cytotoxicity against HepG2 cells than against normal liver cells (L02). Several valuable structure-activity relationships were derived from the cytotoxicity data. In addition, we found that compound 24 could downregulate the expression of the Mcl-1 protein, induce changes in the mitochondrial membrane potential and induce apoptosis in HepG2 cells via the mitochondrial pathway. Compound 24 was also shown to inhibit topoisomerase (topo) II activity and downregulate the levels of both topo II mRNA and protein in HepG2 cells. The present results suggest that due to its potent cytotoxicity and good tumour selectivity, compound 24 may be exploited as a potential lead compound in the development of a new anti-tumour agent with specific activity against liver cancer.