The mechanism by which SIRT1 regulates autophagy and EMT in drug-resistant oesophageal cancer cells.

Cancer cell resistance presents a significant clinical challenge. The mechanisms underlying drug resistance in cancer cells are intricate and remain incompletely understood. Notably, tumor cell resistance often coincides with the epithelial-mesenchymal transition (EMT). In this study, we observed an elevation in autophagy levels following the development of drug resistance in oesophageal cancer cells. Inhibition of autophagy led to a reduction in drug-resistant cell migration and the inhibition of EMT. Furthermore, we identified an upregulation of SIRT1 expression in drug-resistant oesophageal cancer cells. Subsequent inhibition of SIRT1 expression in drug-resistant cells resulted in the suppression of autophagy levels, migration ability, and the EMT process. Our additional investigations revealed that a SIRT1 inhibitor effectively curbed tumor growth in human oesophageal cancer xenograft model mice (TE-1, TE-1/PTX) without evident toxic effects. This mechanism appears to be associated with the autophagy levels within the tumor tissue.

Development and validation of a sensitive UPLC-MS/MS analytical method for GFH009 in rat plasma and its application to toxicokinetics studies.

GFH009 is a potent, highly selective, small molecule that targets and inhibits the activity of the CDK9/cyclin T1 regulatory complex of P-TEFb. This study aimed to develop and validate a highly selective and sensitive ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for precise quantification of GFH009 in rat plasma. This method was subsequently employed for conducting toxicokinetic studies of GFH009 in rats. Plasma was prepared using a simple protein precipitation method by acetonitrile. Chromatographic separation of the analytes was achieved on a BEH C18 analytical column with a rapid 3.0 min run time and a flow rate of 0.5 ml/min. The calibration curves for plasma samples exhibited excellent linearity over a wide concentration range of 1.0-1,000 ng/ml for GFH009. Intra- and inter-day accuracies were within 92.7-105.7%, and precisions were no more than 6.7%. Furthermore, the analyte demonstrated stability under four different storage conditions, with variations of <15.0%. This study pioneers a methodological innovation by introducing a highly reliable, specific and sensitive analytical method for GFH009 in rat plasma. The successful application of this method in toxicokinetic studies further underscores its significance, offering valuable insights for the methodology of clinical pharmacokinetic research.

Luteolin attenuates cancer cell stemness in PTX-resistant oesophageal cancer cells through mediating SOX2 protein stability.

Cancer drug resistance is a formidable obstacle that enhances cancer stem-like cell properties, tumour metastasis and relapse. Luteolin (Lut) is a natural flavonoid with strong antitumor effects. However, the underlying mechanism(s) by which Lut protects against paclitaxel-resistant (PTX-resistant) cancer cell remains unknown. Herein, we found that Lut significantly attenuated the stem-like properties of PTX-resistant cancer cells by downregulating the expression of SOX2 protein. Additionally, further study showed that Lut could inhibit the PI3K/AKT pathway to decrease the phosphorylation level of AKT(S473) and UBR5 expression, which is an ubiquitin E3 ligase that promotes SOX2 degradation. In addition, Lut also inhibited PTX-resistant cancer cell migration and invasion by blocking epithelial-mesenchymal transition (EMT). Importantly, Lut inhibited the tumorigenic ability of oesophageal PTX-resistant cancer cells and showed no obvious toxicity in vivo. Thus, Lut has potential as a promising agent for drug-resistant oesophageal cancer therapy.

Luteolin combined with low-dose paclitaxel synergistically inhibits epithelial-mesenchymal transition and induces cell apoptosis on esophageal carcinoma in vitro and in vivo.

Although paclitaxel is a promising frontline chemotherapy agent for various malignancies, the clinical applications have been restricted by side effects, drug resistance, and cancer metastasis. The combination of paclitaxel and other agents could be the promising strategies against malignant tumor, which enhances the antitumor effect through synergistic effects, reduces required drug concentrations, and also suppresses tumorigenesis in multiple ways. In this study, we found that luteolin, a natural flavonoid compound, combined with low-dose paclitaxel synergistically regulated the proliferation, migration, epithelial-mesenchymal transition (EMT), and apoptosis of esophageal cancer cells in vitro, as well as synergistically inhibited tumor growth without obvious toxicity in vivo. The molecular mechanism of inhibiting cell migration and EMT processes may be related to the inhibition of SIRT1, and the mechanism of apoptosis induction is associated with the reactive oxygen species (ROS)/c-Jun N-terminal kinase (JNK) pathway-mediated activation of mitochondrial apoptotic pathway.

EMT and Cancer Cell Stemness Associated With Chemotherapeutic Resistance in Esophageal Cancer.

Drug resistance often occurs after chemotherapy in esophageal cancer patients, leading to cancer metastasis and recurrence. However, the relationship among cancer cell migration, recurrence and drug resistance in esophageal cancer drug-resistant cells has not been clearly explained. In this study, we constructed paclitaxel (PTX)-resistant esophageal cancer cells to explore the causes of drug resistance and poor prognosis after chemotherapy in esophageal cancer. Colony formation assay was used to evaluate the difference of colony formation between parental cells and drug resistance cells. Microsphere formation assay was used to examine the phenotype of stem cells. Wound healing and Transwell assays were used to detect the migration ability of drug-resistant cells. Western blotting and immunofluorescence assays were used to explore the mechanisms. Finally, we used nude mouse xenograft model to explore the tumor characteristics and the expression of relative proteins to verify our findings in vivo. Our study demonstrated that the cancer cell stemness characteristics exist in drug-resistant esophageal cancer cells, that expressed the biomarkers of stem cells and were prone to epithelial-mesenchymal transition (EMT). Our results suggested that the expression of EMT biomarkers and stemness-related proteins increased in esophageal cancer cells after continuously using chemotherapeutic drugs for a period of time. This study indicated that simultaneously targeting EMT and stemness could be a better strategy for the treatment of esophageal cancer drug resistance.

Lateral position: a friendly surgical position for intramedullary nailing of tibial shaft fractures via infrapatellar approach.

BACKGROUND: The conventional infrapatellar approach to intramedullary nailing of tibial fractures adopts the supine high-flexion knee position. However, this has disadvantages including difficulty in obtaining the proximal tibial anteroposterior view during intraoperative fluoroscopy, prolonged duration of fluoroscopy. Accordingly, the present study investigated the utility of the lateral position in the infrapatellar approach to intramedullary nailing of tibial shaft fractures. METHODS: The present study was a retrospective analysis of 112 patients who sustained closed tibial shaft fractures and treated with intramedullary nailing via the infrapatellar approach. Patients were divided into two groups according to surgical position: lateral or supine. The demographic and clinical data were collected and analyzed. RESULTS: There were 54 patients in the lateral and 58 in the supine position groups. The duration of surgery and fluoroscopy was shorter in the lateral group than the supine group (p < 0.05). Blood loss during surgery was lower in the lateral compared with supine position group (p < 0.05). The malunion rate was lower in the lateral position group as compared with the supine position group (p < 0.05); moreover, fewer surgical assistants were needed than in the supine group (p < 0.05). There were no significant differences in fracture healing time, other complications between the two groups (p > 0.05). CONCLUSIONS: The lateral position was a more convenient choice for intramedullary nailing of tibial shaft fractures via infrapatellar approach.

Synthesis and in vitro and in vivo biological evaluation of novel derivatives of flexicaulin A as antiproliferative agents.

As our research focuses on anticancer drugs, a series of novel derivatives of flexicaulin A (FA), an ent-kaurene diterpene, condensed with an aromatic ring were synthesized, and their antiproliferative activities against four human cancer cell lines (TE-1, EC109, MCF-7, and MGC-803) were evaluated. The activities of most of the new compounds were better than those of FA. Compound 2y exhibited the best activity with an IC50 value reaching 0.13 µM against oesophageal cancer cells (EC109 cells). The IC50 values for 2y in normal cells (GES-1 cells and HUVECs) were 0.52 µM and 0.49 µM, respectively. Subsequent mechanistic investigations found that compound 2y can inhibit the proliferation of cancer cells and cell cloning. In addition, 2y could reduce the mitochondrial membrane potential, increase the apoptosis rate, and increase the ROS level in EC109 cells. Moreover, 2y can upregulate the expression of ROS/JNK pathway-related proteins (p-ASK1, p-MKK4, p-JNK, and p-Cjun (ser63)) and pro-apoptotic proteins (Bax, Bad, and Bim). In vivo experiments showed that 2y can inhibit tumour growth in nude mice. The mechanism involves an increase in protein expression in the ROS pathway, leading to changes in apoptosis-related proteins. In addition, compound 2y shows low toxicity. These results indicate that compound 2y holds promising potential as an antiproliferative agent.

Menopause and frailty: a scoping review.

IMPORTANCE AND OBJECTIVE: Frailty refers to the decline in physiological reserve capacity caused by the deterioration of multiple physiological systems (brain, endocrine system, immune system, and skeletal muscle), leading to increased vulnerability and decreased stress capacity. Women have a higher prevalence of frailty than men, although the epidemiological factors underlying this phenomenon are not fully understood. Menopause and menopause-related characteristics may be among the contributing factors. Hence, the purpose of this scoping review was to explore the relationship between menopause and frailty. We attempted to summarize information such as the age that menopause occurs, years since menopause, types of menopause, and hormones and inflammatory markers of frailty among postmenopausal women. METHODS: PubMed, EMBASE, The Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature and Web of Science, the China National Knowledge Infrastructure, the China Biomedical Literature Service System, Wanfang Database and the WeiPu (VIP) Database were searched from inception until April 3, 2019. Supplementary searches of the references, cited documents, and similar documents of the included literature were also carried out. DISCUSSION AND CONCLUSIONS: Of 762 papers identified, 15 articles matching the criteria were included. The prevalence of frailty among postmenopausal women ranged from 5.9% to 57.3%. Existing studies suggest that menopause is associated with frailty. Early menopause, hysterectomy, low-free testosterone levels, and high C-reactive protein levels may increase the likelihood of frailty among postmenopausal women. Few original studies have explored the relationship between estrogen and frailty and the results of these studies are conflicting. Changes in hormone and inflammatory cytokine levels may mediate frailty among postmenopausal women. More in-depth research would be required to better understand the physiological and etiological mechanisms of the occurrence of frailty among postmenopausal women.

Mediation effect of AhR expression between polycyclic aromatic hydrocarbons exposure and oxidative DNA damage among Chinese occupational workers.

Polycyclic aromatic hydrocarbons (PAH) are well-known to be carcinogenic and the mechanisms that it contributes to oxidative DNA damage and aryl hydrocarbon receptor (AhR)-dependent induction are also well understood. However, little is known about the associations between PAH exposure, AhR expression, and oxidative DNA damage. We investigated their associations of AhR expression and oxidative DNA damage related to PAH exposure among 310 workers from a coke-oven plant in China. Urine biomarkers of PAH exposure (2-hydroxynaphthalene, 2-NAP; 2-hydroxyfluorene, 2-FLU; 9-hydroxyphenanthren, 9-PHE; and 1-hydroxypyrene, 1-OHP) and a marker of oxidative damage (8-hydroxy- 2'- deoxyguanosine, 8-OHdG) were measured by high performance liquid chromatography. AhR expression in venous blood was measured by reverse transcription -polymerase chain reaction. The results showed that increasing levels of urinary 1-OHP was positively associated with high 8-OHdG (OR (95% CI) was 4.01 (1.41-11.45) for 4th quartile, compared with 1st quartile, P for trend = 0.013). The similar associations were also found between urinary 1-OHP and high-AhR expressions (4th vs. 1st quartile = 3.50, 95% CI: 1.24-9.87, P for trend = 0.029). A significant association between AhR expression and high 8-OHdG was also found (4th vs. 1st quartile = 2.44, 95% CI: 1.05-5.70, P for trend = 0.027). In addition, mediation analysis showed the AhR expression could explain 35.9% of the association of oxidative DNA damage related to PAH exposure. Our findings implicated that the association between PAH exposure and oxidative DNA damage may be mediated by AhR expression among Chinese occupational workers.

M2 polarization of monocytes in ankylosing spondylitis and relationship with inflammation and structural damage.

The aim of this study was to evaluate the polarization of peripheral blood monocytes in the patients with ankylosing spondylitis (AS) and to determine the correlations between monocyte polarization and inflammation and structural damage. A total of 120 AS patients, 50 rheumatoid arthritis (RA) patients and 100 healthy controls were enrolled in the study. M1 (CD68+CD192+) and M2 (CX3CR1+CD163+) monocytes were characterized by flow cytometry. Demographic, clinical, radiographic and laboratory data were collected and analyzed. A large increase in M2 (CX3CR1+CD163+) monocytes was observed in AS, and M2/M1 ratio was 7.18 ± 6.12, 2.54 ± 3.14 and 35.61 ± 20.04 in control, RA and AS, respectively. The M2/M1 ratio correlated with modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) (r = 0.565; p < 0.001), ESR (r = -0.321; p < 0.001, CRP (r = -0.265; p < 0.001) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (r = -0.201; p = 0.028). Anti-TNF-α therapy induced a significant reduction in the percentage of M1 monocyte, ESR, CRP and BASDAI in AS patients. The present results demonstrated that M2 type polarized monocytes are predominant in the peripheral blood in AS and the M2/M1 ratio is correlated with structural damage (mSASSS), inflammatory biomarkers (ESR and CRP) and BASDAI.

The effect of total hip replacement on employment in patients with ankylosing spondylitis.

Although total hip replacement (THR) has been proven to be effective, the effect of THR on employment in ankylosing spondylitis (AS) in Chinese population is still unknown. We aimed to demonstrate whether or not patients with AS returned to work following THR and factors associated with the work ability after THR. We performed a retrospective study including a total number of 128 AS patients undergoing THR between 2009 and 2013. Presurgery and postsurgery data including disease state, work status, type of job, and time of resuming work were collected. Factors associated with early return to work were assessed through ordinal regression. Eighty-seven of 128 patients (68 %) were employed within 1 year before THR and 98 returned to work after surgery. Among them, 21, 46, and 31 resumed work by 3, 6, and 12 months postoperation, respectively. Multivariate ordinal regression showed that patients with unilateral THR, younger age, lower BASFI score, employed presurgery, and low or moderate physical demand were more likely to resume work earlier. Most individuals working presurgery returned to work after THR. For young AS patients with hip involvement, THR is an effective treatment for improving and maintaining work ability.

Comparison of Blood Loss After Total Hip Arthroplasty Between Ankylosing Spondylitis and Osteoarthritis.

BACKGROUND: This study was conducted to compare the blood loss during primary total hip arthroplasty (THA) between ankylosing spondylitis (AS) and hip osteoarthritis (OA). METHODS: We reviewed 120 THAs in 68 patients comprising 3 groups: AS with total bony ankylosis of the hips (ASB), AS with stiff hips (ASS), and OA. Demographics, perioperative laboratory values, intraoperative data, blood loss, transfusion rate, transfusion reactions, surgical complications, hospitalization cost, and length of stay (LOS) were collected and analyzed among ASB, ASS, and OA groups. RESULTS: The patients of the ASB and ASS groups were much younger and thinner than those of the OA group. There were no significant differences in the preoperative values of activated partial thromboplastin time, prothrombin time, and international normalized ratio among the 3 groups (all P > .05). The intraoperative blood loss, volume of drainage, hidden blood loss, transfusion rate, transfusion reactions, and hospitalization cost in the ASB group were significantly higher than in the other 2 groups, although not significantly different between the ASS and OA groups (P > .05). CONCLUSION: Both AS and OA can cause hyperosteogeny to the hips, but ASB patients have more serious symptoms in their affected hips. This may cause more blood loss in THA surgery because of bone surface bleeding. The reason that ASB patients suffered more blood loss may be related to the high difficulty and long duration of the operation.

The effect of resveratrol on surgery-induced epidural fibrosis in laminectomy rats.

Epidural fibrosis (EF) is a common complication for the patients who underwent laminectomy. Recently, EF is thought to cause recurrent postoperative pain after laminectomy. Resveratrol has been shown to exert its anti-inflammatory, antifibrotic, and antiproliferative multifaceted properties. The object of this study was to investigate the effects of resveratrol on the prevention of postlaminectomy EF formation in laminectomy rats. A controlled double-blinded study was performed on 60 healthy adult Sprague-Dawley rats that underwent lumbar laminectomy at the L1-L2 levels. They were divided randomly into 3 groups (1, 2, and 3) of 20 rats each-group 1: resveratrol treatment group; group 2: resveratrol dilution saline treatment group; group 3: sham group (rats underwent laminectomy without treatment). All rats were killed 4 weeks after operation. The Rydell score, hydroxyproline content, vimentin cells density, fibroblasts density, and inflammatory factors expressional levels all suggested better results in resveratrol group than the other two groups. Resveratrol is able to inhibit fibroblasts proliferation, and TGF- ß 1 and IL-6 expressions and prevent epidural fibrosis in postlaminectomy rat.

[Study on safety of apnea test in clinical determination of brain death].

OBJECTIVE: To determine the occurrence of severe complications such as hypotension, pulmonary artery hypertension as well as hypercapnia during apnea test in the affirmation of brain death and to investigate the possible effective prophylactic interventions. METHODS: Conventional apnea test was performed in 15 clinically suspected brain death patients. Stable circulation was achieved by adjusting preload only (n=4) or combined with titrating norepinephrine (NE, n=11). Blood gas was respectively analyzed before apnea test, 10 minutes after 100% fraction of oxygen (FiO(2)) ventilation, at each 2-minute interval after disconnecting ventilator and 5 minutes after reventilation. Hemodynamic parameters and dosage of NE were recorded at the same time points. Plasma concentration of lactate was measured before and at the end of apnea test. RESULTS: Spontaneous breath occurred in 1 case among 15 suspected brain death patients. Partial pressure of carbon dioxide (PaCO(2)) reached higher than 60 mm Hg (1 mm Hg=0.133 kPa) within 8 minutes in positive apnea test patients (P<0.01). pH significantly decreased (P<0.05), but partial pressure of oxygen (PaO(2)) maintained higher than 100 mm Hg during the test. Heart rate (HR) and mean artery pressure (MAP) slightly lowered (P>0.05), but pulmonary artery pressure (PAP) markedly elevated (P<0.05) at the end of the test in comparison with their base lines. On the other hand, HR and MAP increased in the negative apnea test case after ventilator disconnection. Severe arrhythmia events did not occur in all the cases. There was no change in the dosage of NE infusion, the range of which was 0.10-0.60 microg.kg(-1).min(-1) with the mean level of (0.23+/-0.17) microg.kg(-1).min(-1). The trend of HR, MAP, PAP and pulmonary arterial wedge pressure (PAWP) alterations was the same in patients no matter whether or not NE was used. HR, MAP and PAWP lowered, while PAP enhanced. Plasma lactate level was not significantly altered at the end of the test compared with the base line (from (1.41+/-0.05) mmol/L to (1.47+/-0.07) mmol/L). CONCLUSION: Adequate oxygenation could be maintained during conventional apnea test. The risk of inducing severe hypotension is low in non brain death patients. Based on adequate preload, low dose of NE infusion could prevent patients with high risk circulation instability from severe hypotension.