The Morel-Lavallée Lesion: Review and Update on Diagnosis and Management.

Morel-Lavallée lesion is a closed soft tissue degloving injury usually associated with high-velocity trauma. It most commonly occurs in the thigh, hip, and pelvis. Because such lesions are prone to a missed or delayed diagnosis, it may present a potential risk of infection at the fracture site once it progresses. Therefore, timely identification and management of Morel-Lavallée lesion is crucial. Moreover, there are no relevant guidelines for the treatment of Morel-Lavallée lesion. Based on the above facts, we reviewed the etiology, epidemiology, pathophysiology, clinical presentation, imaging features, treatment, prognosis, and complications of Morel-Lavallée lesion with the aim of providing a comprehensive overview of Morel-Lavallée lesion, increasing awareness of this injury among orthopaedic surgeons, and thus providing a management algorithm that can be applied to this injury.

Identification of Flavonoids from Scutellaria barbata D. Don as Inhibitors of HIV-1 and Cathepsin L Proteases and Their Structure-Activity Relationships.

Scutellaria barbata D. Don (SB, Chinese: Ban Zhi Lian), a well-known medicinal plant used in traditional Chinese medicine, is rich in flavonoids. It possesses antitumor, anti-inflammatory, and antiviral activities. In this study, we evaluated the inhibitory activities of SB extracts and its active components against HIV-1 protease (HIV-1 PR) and SARS-CoV2 viral cathepsin L protease (Cat L PR). UPLC/HRMS was used to identify and quantify the major active flavonoids in different SB extracts, and fluorescence resonance energy transfer (FRET) assays were used to determine HIV-1 PR and Cat L PR inhibitions and identify structure-activity relationships. Molecular docking was also performed, to explore the diversification in bonding patterns of the active flavonoids upon binding to the two PRs. Three SB extracts (SBW, SB30, and SB60) and nine flavonoids inhibited HIV-1 PR with an IC50 range from 0.006 to 0.83 mg/mL. Six of the flavonoids showed 10~37.6% inhibition of Cat L PR at a concentration of 0.1 mg/mL. The results showed that the introduction of the 4'-hydroxyl and 6-hydroxyl/methoxy groups was essential in the 5,6,7-trihydroxyl and 5,7,4'-trihydroxyl flavones, respectively, to enhance their dual anti-PR activities. Hence, the 5,6,7,4'-tetrahydroxyl flavone scutellarein (HIV-1 PR, IC50 = 0.068 mg/mL; Cat L PR, IC50 = 0.43 mg/mL) may serve as a lead compound to develop more effective dual protease inhibitors. The 5,7,3',4'-tetrahydroxyl flavone luteolin also showed a potent and selective inhibition of HIV-1 PR (IC50 = 0.039 mg/mL).

Clinical Outcomes of the Modified Stoppa Combined with Iliac Fossa Approach for Complex Acetabular Fractures: A Medium- and Long-term Retrospective Study.

OBJECTIVE: The modified Stoppa combined with iliac fossa approach has gained increasing popularity. Although early clinical outcomes have been satisfactory, extensive long-term clinical outcomes are relatively scarce. The purpose of this study was to evaluate the medium- and long-term outcomes of this approach for complex acetabular fractures. METHODS: This was a retrospective study involving 57 patients with complex acetabular fractures from January 2009 to January 2016. All fractures were treated with the modified Stoppa combined with iliac fossa approach. Follow-up was at least 5 years. Primary outcome measures, including quality of reduction and clinical outcomes, were recorded by an independent observer. Secondary outcome measures included time to surgery, surgical time, intraoperative blood loss, and perioperative complications. RESULTS: Fifty-seven patients (range, 18-80 years) included 46 males and 11 females. There were 32 cases on the left side and 25 cases on the right side. The most common associated injury was pulmonary contusion. According to the Judet-Letournel classification, there were 27 both-column fractures, 16 anterior column with posterior hemitransverse fractures and 14 T-type fractures. The average time from injury to surgery was 7.3 days. The average intraoperative blood loss and transfusion were 750.9 ml and 564.3 ml, respectively. All fractures healed within 6 months after surgery. The average follow-up time was 7.7 years, and there was no loss of follow-up. The quality of reduction was graded as anatomical in 23 cases (40.4%), imperfect in 22 cases (38.6%), and poor in 12 cases (21.0%). According to grading system of Merle d' Aubigne and Postel, clinical outcomes at 1 year follow-up were excellent in 17 cases (29.8%), good in 25 cases (43.9%), fair in four cases (7.0%), and poor in 11 cases (19.3%). The excellent and good rate was 73.7% and the difference was not statistically significant compared with the clinical outcomes at the last follow-up. Intraoperative complications included four cases of obturator nerve injury and two cases of vascular injury. Postoperative complications included one case of wound delayed healing, two cases of deep vein thrombosis, two cases of avascular necrosis of femoral head, three cases of heterotopic ossification and five cases of post-traumatic arthritis. Only one of these patients underwent reoperation for femoral head necrosis. CONCLUSIONS: The modified Stoppa combined with iliac fossa approach can achieve satisfactory reduction quality and hip function. It might be a valuable alternative to the ilioinguinal approach for the surgical management of acetabular fractures.

Cancer-related fatigue in hospitalised patients treated for lymphoma and its burden on family caregivers.

OBJECTIVE: To investigate the prevalence of cancer-related fatigue (CRF) in patients with lymphoma and to explore the burden of CRF on the family caregivers (FCs). METHODS: A cross-sectional study was conducted in a university-affiliated tertiary care hospital in China. Patients with lymphoma who received treatment in the in-patient ward of the Haematology Department were consecutively recruited. Face-to-face interviews were conducted to gather information related to the patients' sociodemographic characteristics and perceived CRF and its burden on the FCs. Cochran-Armitage trend analysis and Multivariable logistic regression analyses were employed to determine the association between CRF and the FCs' burden. RESULTS: Of the 116 cancer patient-FC dyads, about 70% of patients experienced some level of fatigue, while 51% of unpaid family members suffered some degree of depression. The Cochran-Armitage trend analysis showed that the FCs' burden significantly increased with the severity of CRF. Logistic regression indicated that the FCs of the patients reporting fatigue experienced a higher burden in both the unadjusted and adjusted models. CONCLUSION: The prevalence of CRF appeared to be high among patients with lymphoma. It might be important to design innovative health-promoting practices for ameliorating or preventing the impact of fatigue.

Prevalence and association of anxiety and depression among orthopaedic trauma inpatients: a retrospective analysis of 1994 cases.

BACKGROUND: Patients with traumatic injuries are often accompanied by emotional disorders, which seriously impede functional gains. The objective of this study was to identify the prevalence and risk factors associated with underlying anxiety and depression in orthopaedic trauma patients. METHODS: From July 2015 to December 2017, all orthopaedic trauma patients were included in the retrospective study. Patients with conditions that might affect cognitive impairment were excluded from the study. Basic demographic data were collected. All patients were screened for emotional disorders on admission using a simple questionnaire called "Huaxi Emotional-Distress Index" (HEI). Bivariate analyses and logistic regression were used to identify the factors associated with a HEI score of > 8. RESULTS: One hundred and sixty-two patients (8.1%) had a HEI score of > 8. About 1.0% of enrolled patients had severe emotional disorders (HEI score ≥ 17). The reasons caused by emotional disorders in patients with orthopaedic trauma were a higher Injury Severity Score (ISS), a higher visual analogue score (VAS) and type of surgery. On logistic regression, marital status was a protective factor for emotional disorders, while VAS and ISS were the risk factors for emotional disorders. CONCLUSIONS: Although a significantly low percentage of orthopaedic trauma patients in our setting have emotional disorders, traumatic orthopaedic surgeons still need to pay attention to the risk of emotional disorders and integrate effective screening tools into clinical practice to screen for these factors and stratify emotional disorders. Appropriate targeted psychological intervention and treatment should be adopted according to the stratification of emotional disorders.

Author Correction: Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of mice.

During re-read of our previously article Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of micepublished in Acta Pharmacologica Sinica, we were regretted to point out a mistake shown in Fig. 2a. The representative figure chosen to indicate the inhibitory effect of 4 mg/kg of plumbagin treatment at 1 week against MDA-MB-231SArfp cells localization within bone environment was incorrect due to the mishandling in manuscript preparation. Although this correction does not affect the results and conclusion of the paper, all the authors agree on the correction of our negligence as providing the corrected Fig. 2a presented below. We feel sorry and apologize for all the inconvenience it caused.An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Correction to: Suppressive effects of plumbagin on invasion and migration of breast cancer cells via the inhibition of STAT3 signaling and down-regulation of inflammatory cytokine expressions.

[This corrects the article DOI: 10.4248/BR201304007.].

Author Correction: Synergistic suppression of human breast cancer cells by combination of plumbagin and zoledronic acid in vitro.

The authors regretted to find the mis-representative images in Fig. 3a, c and Fig. 4a, c when re-read our previously published article Synergistic suppression of human breast cancer cells by combination of plumbagin and zoledronic acid In vitro (DOI: 10.1038/aps.2015.42) in the journal of Acta Pharmacologica Sinica. This mistake occurred due to the careless compilation when the authors tried to show the synergistic effect against tumor apoptosis during figure presentation process. The right Fig. 3a, c and Fig. 4a, c were provided below. Despite that this correction does not affect the results and conclusions of the aforementioned paper, all the authors still consent on the correction of this negligence. We apologize to the Editor and the readership of the journal for any inconvenience caused. Your thoughtful understanding is highly appreciated.

Molecular pathogenesis of fracture nonunion.

Fracture nonunion, a serious bone fracture complication, remains a challenge in clinical practice. Although the molecular pathogenesis of nonunion remains unclear, a better understanding may provide better approaches for its prevention, diagnosis and treatment at the molecular level. This review tries to summarise the progress made in studies of the pathogenesis of fracture nonunion. We discuss the evidence supporting the concept that the development of nonunion is related to genetic factors. The importance of several cytokines that regulate fracture healing in the pathogenesis of nonunion, such as tumour necrosis factor-α, interleukin-6, bone morphogenetic proteins, insulin-like growth factors, matrix metalloproteinases and vascular endothelial growth factor, has been proven in vitro, in animals and in humans. Nitric oxide and the Wnt signalling pathway also play important roles in the development of nonunion. We present potential strategies for the prevention, diagnosis and treatment of nonunion, and the interaction between genetic alteration and abnormal cytokine expression warrants further investigation. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: A better understanding of nonunion molecular pathogenesis may provide better approaches for its prevention, diagnosis and treatment in clinical practice.

CXCR1/Akt signaling activation induced by mesenchymal stem cell-derived IL-8 promotes osteosarcoma cell anoikis resistance and pulmonary metastasis.

The loss of appropriate cell adhesion normally induces apoptosis via a process termed anoikis. The aim of this study was to investigate the effects of mesenchymal stem cells (MSCs) in the cancer microenvironment on the anoikis resistance and pulmonary metastasis of osteosarcoma (OS) cells, and to evaluate the critical role of the interleukin (IL)-8/C-X-C chemokine receptor (CXCR) 1/Akt-signaling pathway in these processes. Metastatic OS subtype cells, which did or did not interact with MSC-conditioned medium (MSC-CM) in vitro, were isolated from the pulmonary site and named Saos2-lung-M. Both MSC-CM and IL-8 treatment increased the anoikis resistance of Saos2 cells in vitro. Moreover, exogenous MSC-CM promoted the survival and metastasis of Saos2 cells in nude mice. Saos2-lung-M cells were more malignant and resistant to anoikis than parental cells. MSCs secreted IL-8, thereby protecting OS cells from anoikis. Blocking the IL-8/CXCR1/Akt pathway via CXCR1 knockdown inhibited the pulmonary metastasis of Saos2-lung-MSCs and prolonged the survival of tumor-bearing mice. In conclusion, MSCs enhanced OS cell resistance to anoikis and pulmonary metastasis via regulation of the IL-8/CXCR1/Akt pathway. These findings suggest that MSCs can "select for" OS cells with high metastatic potential in vivo, and highlight CXCR1 as a key target in the regulation of pulmonary metastasis of OS cells.

TIMP3 Overexpression Improves the Sensitivity of Osteosarcoma to Cisplatin by Reducing IL-6 Production.

Osteosarcoma is the most common bone cancer in children and adolescents. Tissue inhibitors of metalloproteinases (TIMPs)-3 inhibit matrix metalloproteinases to limit extracellular matrix degradation. Cisplatin is a widely used chemotherapeutic drug used to cure osteosarcoma. Interleukin (IL)-6 and TIMP3 play important roles in the drug resistance of osteosarcoma; however, their relationship in this process remains unclear. This study aimed to explore the role of TIMP3 in the cisplatin sensitivity of osteosarcoma and its underlying molecular mechanisms in vitro and in vivo. We compared TIMP3 expression levels between patients with cisplatin-sensitive and -insensitive osteosarcoma. TIMP3 was overexpressed or knocked down in the Saos2-lung cell line, which is a Saos2 subtype isolated from pulmonary metastases that has higher cisplatin chemoresistance than Saos2 cells. IL-6 expression, cell proliferation, sensitivity to cisplatin, migration, and invasion after TIMP3 overexpression or knockdown were determined. The same experiments were performed using MG63 and U2OS cells. Subsequently, luciferase-labeled Saos2-lung cells overexpressing TIMP3 were injected into the tibiae of nude mice treated with cisplatin. The results showed that IL-6 inhibited TIMP3 expression in Saos2 and Saos2-lung cells via signal transducer and activator of transcription 3 (STAT3) activation. STAT3 knockdown reversed the effect of IL-6. The expression of TIMP3 was higher in patients with cisplatin-sensitive osteosarcoma than in those with insensitive osteosarcoma. IL-6 expression was downregulated upon TIMP3 overexpression, and upregulated by TIMP3 knockdown. TIMP3 overexpression suppressed cell proliferation and enhanced cisplatin sensitivity by activating apoptosis-related signal pathways and inhibiting IL-6 expression in vitro and in vivo. In conclusion, cisplatin sensitivity correlated positively with TIMP3 expression, which is regulated by the IL-6/TIMP3/caspase pathway. The TIMP3 pathway could represent a target for new therapies to treat osteosarcoma.

Defective Circulating Regulatory B Cells in Patients with Dilated Cardiomyopathy.

BACKGROUND/AIMS: Newly identified IL-10-producing regulatory B cells (Bregs) have been shown to play an important role in the suppression of immune responses. Chronic immune activation participates in the pathogenesis of dilated cardiomyopathy (DCM) but whether Bregs are involved in its development remains unclear. We aimed to investigate the circulating frequency and function of Bregs in DCM. METHODS: In total, 35 DCM patients (20 men and 15 women) and 44 healthy controls (23 men and 21 women) were included in the experiment, and the frequency of Bregs was detected using flow cytometry. RESULTS: According to our results, the frequency of circulating IL-10-producing Bregs was significantly lower in DCM patients compared with healthy controls. Furthermore, the CD24hiCD27+ B cell subset in which IL-10-producing Bregs were mainly enriched from DCM patients showed impaired IL-10 expression and a decreased ability to suppress the TNF-α production of CD4+CD25- Tconv cells and to maintain Tregs differentiation. Correlation analysis showed that the frequency of IL-10-producing Bregs and the suppressive function of CD24hiCD27+ B cells were positively correlated with left ventricular ejection fraction and negatively correlated with NT-proBNP in DCM patients. CONCLUSIONS: In conclusion, the reduced frequency and impaired functions suggest a potential role of Bregs in the development of DCM.

Bacterial inhibition potential of quaternised chitosan-coated VICRYL absorbable suture: An in vitro and in vivo study.

BACKGROUND/OBJECTIVE: As a widely used absorbable suture with antibacterial property, triclosan- coated polyglactin suture (Vicryl Plus) has been extensively utilized to reduce the occurrence rate of surgical site infections (SSIs) in orthopaedic surgery. However, the potential toxicity and side-effects of triclosan raised increasing concerns about its biological safety. This study aimed to investigate the antimicrobial activity and biocompatibility of quaternised chitosan-coated Vicryl suture (HV) both in vitro and in vivo. METHODS: In this study, a modified chitosan derivate, (hydroxypropyltrimethyl ammonium chloride chitosan, HACC), was coated over the surface of the absorbable Vicryl suture. Two standard bacteria strains, Staphylococcus epidermidis (ATCC35984) and methicillin-resistant Staphylococcus aureus (ATCC43300), were selected to evaluate bacterial adhesion and biofilm formation on the sutures at 6, 24 and 48 h in vitro. Additionally, human skin-derived fibroblasts cells were used to test the cytocompatibility of the sutures. Furtherly, sutures contaminated with methicillin-resistant S. aureus were implanted subcutaneously in SD rats in order to confirm the in vivo antibacterial performance and biocompatibility. RESULTS: We found that HACC-coated Vicryl suture (HV) exhibited significant anti-bacterial effects on the two tested strains. The bacterial attachment and biofilm formation on the surface of the HV sutures were found to be comparable to that of Vicryl Plus sutures (VP). Moreover, all the four tested sutures presented good cytocompatibility with human skin-derived fibroblasts cells. Histology and immunohistochemistry results indicated that the infections and inflammations were significantly inhibited around the HV and VP sutures. CONCLUSION: In general, the present study demonstrated that the quaternised chitosan coating is a flexible and cost-effective alternative strategy to prevent the suture related surgical site infections in orthopaedic practices.

Functional differences between AMPK α1 and α2 subunits in osteogenesis, osteoblast-associated induction of osteoclastogenesis, and adipogenesis.

The endocrine role of the skeleton-which is impaired in human diseases including osteoporosis, obesity and diabetes-has been highlighted previously. In these diseases, the role of AMPK, a sensor and regulator of energy metabolism, is of biological and clinical importance. Since AMPK's main catalytic subunit α has two isoforms, it is unclear whether functional differences between them exist in the skeletal system. The current study overexpressed AMPKα1 and α2 in MC3T3-E1 cells, primary osteoblasts and mouse BMSCs by lentiviral transduction. Cells overexpressing AMPKα2 showed higher osteogenesis potential than AMPKα1, wherein androgen receptor (AR) and osteoactivin played important roles. RANKL and M-CSF were secreted at lower levels from cells overexpressing α2 than α1, resulting in decreased osteoblast-associated osteoclastogenesis. Adipogenesis was inhibited to a greater degree in 3T3-L1 cells overexpressing α2 than α1, which was modulated by AR. An abnormal downregulation of AMPKα2 was observed in human BMSCs exhibiting the fibrous dysplasia (FD) phenotype. Overexpression of AMPKα2 in these cells rescued the defect in osteogenesis, suggesting that AMPKα2 plays a role in FD pathogenesis. These findings highlight functional differences between AMPKα1 and α2, and provide a basis for investigating the molecular mechanisms of diseases associated with impaired functioning of the skeletal system.

In vivo evaluation of the anti-infection potential of gentamicin-loaded nanotubes on titania implants.

Titanium-based implants have been widely used in orthopedic surgery; however, failures still occur. Our in vitro study has demonstrated that gentamicin-loaded, 80 nm-diameter nanotubes possessed both antibacterial and osteogenic activities. Thus, the aim of this study was to further investigate the in vivo anti-infection effect of the titanium implants with gentamicin-loaded nanotubes. Thirty-six male Sprague Dawley rats were used to establish an implant-associated infection model. A volume of 50 µL Staphylococcus aureus suspension (1×10(5) CFU/mL) was injected into the medullary cavity of the left femur, and then the titanium rods without modification (Ti), titanium nanotubes without drug loading (NT), and gentamicin-loaded titanium nanotubes (NT-G) were inserted with phosphate-buffered saline-inoculated Ti rods as a blank control. X-ray images were obtained 1 day, 21 days, and 42 days after surgery; micro-computed tomography, microbiological, and histopathological analyses were used to evaluate the infections at the time of sacrifice. Radiographic signs of bone infection, including osteolysis, periosteal reaction, osteosclerosis, and damaged articular surfaces, were demonstrated in the infected Ti group and were slightly alleviated in the NT group but not observed in the NT-G group. Meanwhile, the radiographic and gross bone pathological scores of the NT-G group were significantly lower than those of the infected Ti group (P<0.01). Explant cultures revealed significantly less bacterial growth in the NT-G group than in the Ti and NT groups (P<0.01), and the NT group showed decreased live bacterial growth compared with the Ti group (P<0.01). Confocal laser scanning microscopy, scanning electron microscopy, and histopathological observations further confirmed decreased bacterial burden in the NT-G group compared with the Ti and NT groups. We concluded that the NT-G coatings can significantly prevent the development of implant-associated infections in a rat model; therefore, they may provide an effective drug-loading strategy to combat implant-associated infections in clinic.

AMPK promotes osteogenesis and inhibits adipogenesis through AMPK-Gfi1-OPN axis.

Several metabolic, genetic and oncogenic bone diseases share the common pathological phenotype of defective bone marrow stromal cell (BMSC) differentiation. Many reports in bone science in the past several years have suggested that the skeleton also has an endocrine role. The role of AMP-activated protein kinase (AMPK) as an energy metabolism sensor and how it regulates BMSC differentiation is largely unknown. In the current study, we used AMPK agonists to activate AMPK in MC3T3-E1 cells to investigate the functional roles of AMPK in osteogenesis. However, metformin and AICAR failed to activate AMPK consistently. Therefore, we established MC3T3-E1 and 3T3-L1 cell models of AMPK α subunit overexpression through lentivirus vector, in which AMPK was overactivated. AMPK hyperactivation stimulated MC3T3-E1 cell osteogenesis and inhibited 3T3-L1 cell adipogenesis. Osteopontin (OPN) mediated AMPK regulation of osteogenesis and adipogenesis. Furthermore, we provided evidence that the transcriptional repressor growth factor independence-1 (Gfi1) was downregulated and disassociated from the OPN promoter in response to AMPK activation, resulting in the upregulation of OPN. Overexpression of wild-type and dominant-negative Gfi1 modulated MC3T3-E1 osteogenesis and 3T3-L1 adipogenesis. Further evidence suggested that AMPK enhanced ectopic bone formation of MC3T3-E1 cells through the AMPK-Gfi1-OPN axis. In conclusion, AMPK was sufficient to stimulate osteogenesis of MC3T3-E1 cells and inhibit adipogenesis of 3T3-L1 cells through the AMPK-Gfi1-OPN axis. These findings helped elucidate the molecular mechanisms underlying AMPK regulation of osteogenesis and adipogenesis.

Mesenchymal stem cells promote osteosarcoma cell survival and drug resistance through activation of STAT3.

Increasing evidence suggests that the tumor microenvironment plays a key role in the development of drug resistant tumor cells. In this study, we tried to determine whether the mesenchymal stem cells (MSCs) in the tumor microenvironment contribute to the increased chemoresistance of osteosarcoma. We found that exposure of Saos-2 and U2-OS cells to MSCs conditioned medium (CM) increased the viable cells in the presence of therapeutic concentrations of doxorubicin or cisplatin. Meanwhile, the MSC CM-associated pro-proliferative effects were accompanied by reduced caspase 3/7 activity and Annexin V binding. We confirmed that STAT3 activation by IL-6 regulates MSCs-induced chemoresistance. Blockade of this signal re-sensitized drug-resistant Saos-2 cells to drug treatment. Using a osteosarcoma mouse model with co-injection of MSCs with Saos-2cells, we found that inhibition of STAT3 prolonged the survival time of tumor bearing mice by suppressing tumor growth and increasing the sensitivity of tumor cells to doxorubicin. Finally, we demonstrated that increased expression of p-STAT3, multidrug resistance protein (MRP) and P-glycoprotein (MDR-1) was associated with high chemotherapy resistance in clinical osteosarcoma samples. Collectively, our findings suggest that MSCs within the tumor microenvironment may represent a new target to enhance chemotherapeutic efficacy in osteosarcoma patients.

TIMP3 regulates osteosarcoma cell migration, invasion, and chemotherapeutic resistances.

Tissue inhibitors of metalloproteinases (TIMPs) inhibit matrix metalloproteinases (MMPs) to limit degradation of the extracellular matrix. Low levels of TIMP3 have been demonstrated in cancer tissues at advanced clinical stages, with positive distant metastasis and chemotherapeutic resistance. We examined the role of TIMP3 in osteosarcoma (OS) cell invasiveness and chemoresistance. TIMP3 was overexpressed or knocked down in the human OS cell lines Saos2 and MG63. Cell migration and invasion capacities were then evaluated using Transwell assays, and resistance to cisplatin was assessed by CCK-8 assay and flow cytometry. Real-time PCR and western blotting were used to investigate activation of signaling pathways downstream of TIMP3. Overexpression of TIMP3 inhibited the migration and invasion of Saos2 and MG63 cells, while knockdown of TIMP3 had the opposite effect. Cell survival after exposure to cisplatin was inhibited by TIMP3 overexpression in both Saos2 and MG63 cells. Consistently, downregulation of TIMP3 gene expression significantly decreased the sensitivity of OS cells to cisplatin treatment. MMP1, MMP2, Bcl-2, and Akt1 were all downregulated following TIMP3 overexpression, while Bax and cleaved caspase-3 were upregulated. TIMP3 knockdown had opposite effects on the regulation of these genes. Taken together, our findings suggest TIMP3 as a new target for inhibition of OS progression and chemotherapeutic resistance.

CXCR1 knockdown improves the sensitivity of osteosarcoma to cisplatin.

Chemotherapy resistance is a major cause of poor prognoses for osteosarcoma patients. This study aimed to determine whether CXCR1 gene knockdown improves the sensitivity of osteosarcomas to chemotherapy. Both CXCR1 expression and cisplatin sensitivity were investigated and compared in two osteosarcoma cell lines. Sensitivity to the chemotherapy drug cisplatin and apoptosis were investigated with or without stimulation via Interleukin-8 (IL-8), which is a ligand of CXCR1. Furthermore, activation of the Akt signaling pathway was determined. Finally, luciferase-labeled CXCR1-knockdown Saos2-lung cells were injected into the tibiae of nude mice that were treated with cisplatin thereafter. We found that CXCR1 expression and cisplatin sensitivity were negatively correlated in osteosarcoma cell lines. IL-8-induced reduction in sensitivity could be blocked by silencing CXCR1, and CXCR1 knockdown suppressed the Akt signaling pathway. Moreover, CXCR1-knockdown tumors were significantly smaller than control tumors, which was consistent with the luciferase intensity results. The expression levels of IL-8, CXCR1 and p-Akt were suppressed in CXCR1-knockdown cells. Taken together, these data indicate that CXCR1 gene knockdown in osteosarcoma cells improved the sensitivity to chemotherapy and that this process might be regulated in part by the IL-8/CXCR1/Akt signaling pathway.

Synergistic suppression of human breast cancer cells by combination of plumbagin and zoledronic acid In vitro.

AIM: Zoledronic acid (ZA), a bisphosphonate, is currently used in combination with chemotherapeutic agents to suppress breast cancer cell proliferation or breast cancer-induced osteolysis. The aim of this study was to investigate the effects of ZA combined with a natural anticancer compound plumbagin (PL) against human breast cancer cells in vitro. METHODS: Human breast cancer MDA-MB-231SArfp cells were treated with ZA, PL or a combination of ZA and PL. The cell growth, apoptosis and migration were evaluated using CCK-8 assay, flow cytometry and transwell assay, respectively. The expression of apoptosis-related proteins was measured using real-time PCR and Western blotting. Synergism was evaluated using Compusyn software, and the combination index (CI) and drug reduction index (DRI) values were determined. RESULTS: PL or ZA alone caused mild cytotoxicity (the IC50 value at 24 h was 12.18 and above 100 µmol/L, respectively). However, the combination of ZA and PL caused a synergistic cytotoxicity (CI=0.26). The DRI values also showed a synergistic effect between PL and ZA, with actual values of 5.52 and 3.59, respectively. Furthermore, PL and ZA synergistically induced apoptosis and inhibited migration of the breast cancer cells. Moreover, the combination of ZA and PL decreased the expression of Notch-1, cleaved PARP, Bcl-2 and Bcl-xl, and increased the expression of cleaved caspase-3, CDKN1A and ID1. When the breast cancer cells were transfected with specific siRNA against Notch-1, the combination of ZA and PL markedly increased the expression of Bcl-2. CONCLUSION: Combination of ZA and PL synergistically suppresses human breast cancer MDA-MB-231SArfp cells in vitro. PL can inhibit ZA-induced activation of the Notch-1 signaling pathway and subsequently reduce the expression of Bcl-2, thus potentiating cancer cell apoptosis.