Metformin sensitises osteosarcoma to chemotherapy via the IGF-1R/miR-610/FEN1 pathway.

Metformin can enhance cancer cell chemosensitivity to anticancer drugs. IGF-1R is involved in cancer chemoresistance. The current study aimed to elucidate the role of metformin in osteosarcoma (OS) cell chemosensitivity modulation and identify its underlying mechanism in IGF-1R/miR-610/FEN1 signalling. IGF-1R, miR-610, and FEN1 were aberrantly expressed in OS and participated in apoptosis modulation; this effect was abated by metformin treatment. Luciferase reporter assays confirmed that FEN1 is a direct target of miR-610. Moreover, metformin treatment decreased IGF-1R and FEN1 but elevated miR-610 expression. Metformin sensitised OS cells to cytotoxic agents, while FEN1 overexpression partly compromised metformin's sensitising effects. Furthermore, metformin was observed to enhance adriamycin's effects in a murine xenograft model. Metformin enhanced OS cell sensitivity to cytotoxic agents via the IGF-1R/miR-610/FEN1 signalling axis, highlighting its potential as an adjuvant during chemotherapy.

Predicted CD4+ T cell infiltration levels could indicate better overall survival in sarcoma patients.

OBJECTIVE: The role of tumor-infiltrating lymphocytes (TILs) has not yet been characterized in sarcomas. The aim of this bioinformatics study was to explore the effect of TILs on sarcoma survival and genome alterations. METHODS: Whole-exome sequencing, transcriptome sequencing, and survival data of sarcoma were obtained from The Cancer Genome Atlas. Immune infiltration scores were calculated using the Tumor Immune Estimation Resource. Potential associations between abundance of infiltrating TILs and survival or genome alterations were examined. RESULTS: Levels of CD4+ T cell infiltration were associated with overall survival of patients with pan-sarcomas, and higher CD4+ T cell infiltration levels were associated with better survival. Somatic copy number alterations, rather than mutations, were found to correlate with CD4+ T cell infiltration levels. CONCLUSIONS: This data mining study indicated that CD4+ T cell infiltration levels predicted from RNA sequencing could predict sarcoma prognosis, and higher levels of CD4+ T cells infiltration indicated a better chance of survival.

Development and Validation of an Immune-Related Gene Pair Signature in Skin Cutaneous Melanoma.

INTRODUCTION: Skin cutaneous melanoma (SKCM) is a common skin malignancy worldwide, and its metastasis and mortality rates are high. The molecular characteristics exhibited by tumor-immune interactions have drawn the attention from researchers. Therefore, increased knowledge and new strategies to identify effective immune-related biomarkers may improve the clinical management of SKCM by providing more accurate prognostic information. PATIENTS AND METHODS: In this study, we established a prognostic immune-related gene pair (IRGP) signature for predicting the survival of SKCM patients. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases provided gene expression profiles together with clinical information, and the samples were randomly divided into three groups including the training, testing, and validation datasets. The regression model of least absolute shrinkage and selection operator (LASSO) helped to identify a 13-IRGP signature with a significant relation to the survival of SKCM patients. RESULTS: The training, TCGA, and independent sets have an average value of area under the curve of 0.79, 0.76, and 0.82, respectively. In addition, this 13-IRGP signature can noticeably divide SKCM patients into high-risk group and low-risk group with significantly different prognoses. Many biological activities such as gene family were enriched among the genes in our IRGP signature. While analyzing the risk signature and clinical characteristics, there was a large difference in the risk score between T stage and tumor stage grouping. Finally, we constructed a nomogram and forest plots of the risk score and clinical features. CONCLUSION: In summary, we developed a robust 13-IRGP prognostic signature in SKCM, which can identify and provide new insights into immunological biomarkers.

The potentiality of immunotherapy for sarcomas: a summary of potential predictive biomarkers.

Sarcomas are rare and heterogeneous malignant tumors of mesenchymal origin. A total of 25-50% of patients treated with initial curative intent will develop as recurrent and metastatic disease. In the recurrent and metastatic setting, effect of chemotherapy is limited; therefore, more effective therapies are urgently desired. As a brake for activation of T cell, PD-1/PD-L1 plays a crucial role in the progression of tumor by altering status of immune surveillance. Some success has been acquired recently in the use of PD-1/PD-L1 inhibitors for the treatment of several solid tumors, for examples, non-small-cell lung cancer and melanoma. Immunotherapeutic strategies based on PD-1/PD-L1 for sarcomas have also been explored these years. As in other cancers, major challenges are identification of biomarkers to predict response for immunotherapy, optimization of patient's benefit and minimization of side effects. Therefore, we focused on potential biomarkers of immunotherapy for treatment of sarcomas in this review.

miR-193b Increases the Chemosensitivity of Osteosarcoma Cells by Promoting FEN1-Mediated Autophagy.

BACKGROUND: Osteosarcoma (OS) is one of the most common malignant bone tumors and specific microRNAs (miRNAs) are closely associated with malignant OS progression. In this study, we examined the role of microRNA-193b-3p (miR-193b) and the involvement of autophagy and apoptosis in the chemosensitivity of OS cells. METHODS: We employed qRT-PCR, Western blot, and immunohistochemistry to examine the expression levels of miR-193b, flap endonuclease 1 (FEN1), and autophagy-related proteins. Apoptosis was determined by flow cytometry using an Annexin V-FITC/PI apoptosis detection kit. Luciferase reporter assays confirmed the relationship between miR-193b and FEN1. RESULTS: miR-193b was downregulated in OS compared to adjacent normal tissues (p < 0.05). miR-193b overexpression in the OS cell lines induced autophagy and apoptosis, as shown by Western blotting and flow cytometry. Knockdown of FEN1, a structure-specific nuclease overexpressed in OS tissues (p < 0.001), induced apoptosis through activation of autophagy. Luciferase reporter assays confirmed that FEN1 is a direct target of miR-193b, FEN1 knockdown reinforced miR-193b induced apoptosis. Moreover, miR-193b expression enhanced epirubicin-induced autophagy and apoptosis. CONCLUSION: Collectively, the results showed that miR-193b/FEN1 may serve as a novel therapeutic target for OS aimed mainly at the induction of autophagy and apoptosis. The miR-193b/FEN1 axis increased the chemosensitivity of OS cells, while activation of autophagy enhanced the anticancer effects of epirubicin.

EWS-FLI1-mediated tenascin-C expression promotes tumour progression by targeting MALAT1 through integrin α5ß1-mediated YAP activation in Ewing sarcoma.

BACKGROUND: The extracellular matrix has been critically associated with the tumorigenesis and progression of Ewing sarcoma (ES). However, the regulatory and prognostic roles of tenascin-C (TNC) in ES remain unclear. METHODS: TNC expression was examined in specimens by immunohistochemistry, and the association of TNC expression with ES patient survival was also analysed. TNC-knockout cell lines were constructed using CRISPR/Cas9 methods. In vitro experiments and in vivo bioluminescent imaging using BALB/c nude mice were conducted to evaluate the effect of TNC on ES tumour progression. RNA sequencing was performed, and the underlying mechanism of TNC was further explored. RESULTS: TNC was overexpressed in ES tissue and cell lines, and TNC overexpression was associated with poor survival in ES patients. TNC enhanced cell proliferation, migration and angiogenesis in vitro and promoted ES metastasis in vivo. The oncoprotein EWS-FLI1 profoundly increased TNC expression by directly binding to the TNC promoter region. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) upregulation induced by Yes-associated protein (YAP) activation was responsible for TNC-regulated ES tumour progression. Activated integrin α5ß1 signalling might be correlated with YAP dephosphorylation and nuclear translocation. CONCLUSIONS: TNC may promote ES tumour progression by targeting MALAT1 through integrin α5ß1-mediated YAP activation.

LncRNA GAS5 is a critical regulator of metastasis phenotype of melanoma cells and inhibits tumor growth in vivo.

The present study intended to demonstrate the effects of long noncoding RNA growth arrest-specific transcript 5 (GAS5) on the migration and invasion of melanoma cells. We first detected the expression of GAS5 among four kinds of melanoma cell lines, followed by constructing GAS5-knocked down and overexpressed stable cells. Next, we evaluated the effects of GAS5 on cell migration and invasion using wound healing and gelatin zymography assays. Finally, melanoma cells with different GAS5 expression were injected into nude mice, and the tumor volumes were recorded and tumor tissues were analyzed after sacrificing the mice. This study systematically examined the function of GAS5 in mediating melanoma metastasis and revealed that GAS5 plays an anticancer role in melanoma via regulating gelatinase A and B, both in vitro and in vivo.

Lentiviral-mediated overexpression of long non-coding RNA GAS5 reduces invasion by mediating MMP2 expression and activity in human melanoma cells.

The present study evaluated the effects of long non-coding RNA GAS5 on the migration and invasion of melanoma cells. Using the SK-Mel­110 melanoma cell line, we stably expressed GAS5, visualized the distribution of GAS5 by RNA fluorescence in situ hybridization (FISH) and examined changes in cell migration and invasion with Transwell assays. In GAS5 overexpressed SK-Mel­110 cells, migrated and invaded cells decreased by 65.3 and 55.6%, respectively. Moreover, the MMP2 protein level, and its activity was downregulated by 67.9 and 15.8%, respectively. Overexpressing lncRNA GAS5 inhibited the migration and invasion ability of melanoma SK-Mel­110 cells, partially by decreasing the MMP2 expression and its activity. This study is the first to reveal a potential relationship between lncRNA GAS5 and the migration and invasion of melanoma.

Association of CXCR1 and 2 expressions with gastric cancer metastasis in ex vivo and tumor cell invasion in vitro.

BACKGROUND: CXCR1 and CXCR2, cell surface receptors of interleukin-8, regulate cell migration and alteration of their expression has been associated with poor prognosis of various cancers. The aim of this study was to detect their expression in gastric cancer to identify associations with another cell adhesion molecule, matrix metalloproteinase-9 (MMP9), and with clinicopathological data ex vivo, and then explore their potential role in gastric cancer cells in vitro. MATERIALS AND METHODS: A total of 172 cases of gastric cancer tissue specimens were collected for immunohistochemical analysis of CXCR1, CXCR2, and MMP9 expression. Expression of CXCR1 and CXCR2 proteins was knocked in or down using their cDNA and shRNA, respectively, in gastric cancer cell lines to assess the changed cell phenotypes and gene expression. RESULTS: CXCR1, CXCR2, and MMP9 were expressed in 61.0%, 77.9%, and 75.6% of gastric cancer tissues, respectively. Moreover, CXCR1 and CXCR2 expression was associated with tumor differentiations, advanced clinical stages, lymph node, and distant metastasis of gastric cancer. Similarly, MMP9 expression was associated with CXCR1 and CXCR2. Expression of these three proteins was interrelated. In vitro study showed that levels of CXCR1 and CXCR2 proteins were associated with the capacity of gastric cancer cell migration, while knockdown of their expression inhibited gastric cancer cell migration and invasion abilities in vitro. In contrast, overexpression of CXCR1 and CXCR2 proteins promoted tumor cell migration and invasion. At the gene levels, knockdown of CXCR1 or CXCR2 expression suppressed expression of Ets-1, SRC-1, and JNK proteins and phosphorylated c-Jun and Erk1/2. Conversely, upregulation of CXCR1 or CXCR2 promoted expression of Ets-1, SRC-1, JNK, and c-Jun proteins and phosphorylated JNK, c-Jun and Erk1/2. CONCLUSIONS: These findings suggest that CXCR1 and CXCR2 play an important role in gastric cancer progression. Further study will be performed to investigate whether target of their expression can be used as a novel strategy in clinical control of gastric cancer metastasis.

[Application of medial head gastrocnemius muscle flap to limb-salvage operation of proximal tibial malignant tumor].

OBJECTIVE: To evaluate the efficacy of transposition of the medial gastracnemius muscle flap in the limb-salvage operation of the proximal tibial tumors. METHODS: From January 2001 to September 2005, 13 patients (8 males, 5 females; aged 14-57 years, averaged 29.7 years) suffering from the proximal tibial tumors were treated with a limb-salvage operation. Among them, there were 4 patients with osteosarcoma, 6 with malignant fibrous histocytoma, 1 with malignant giant cell tumor, 1 with synovial sarcoma, and 1 with Ewing's sarcoma. According to the Enneking staging system, 1 case was in Stage I B, 9 in Stage II A, and 3 in Stage II B. One or two cycles of neoadjuvant chemotherapy were used to each of the patients before operation. All of the patients underwent the medial head of the gastrocnemius muscle flap transposition to reconstruct the soft tissues after resection of the tumors and reconstruction of the bone defect by prothesis or bone-graft or the two methods combined. RESULTS: The follow-up for 7-47 months (average, 19. 2 months) in all the patients revealed that. there was no flap necrosis, no skin necrosis at the incision margins, and no infection or fracture of the implanted bone. The patient with malignant fibrous histocytoma died of systemic metastasis 20 months after operation. The patient with Ewing's sarcoma had a local tumor recurrence 18 months after operation; though treated with the focal cleaning and the bone cement filling, the patient still developed lung metastasis of the tumor 26 months after operation. The patient with osteosarcoma underwent amputation 12 months after operation because of the tumor recurrence. According to the function assessment by the Mankin system, there were 6 patients who had an excellent result, 4 had a good result, and 3 had a poor result, with a satisfaction rate of 77%. CONCLUSION: The flap transposition of the medial head of the gastrocnemius muscle can reconstruct the soft tissue defect, decrease the local complication rate and improve the clinical outcome of the limb salvage for the proximal tibia malignant tumor.

[Treating metastatic vertebral tumor with percutaneous vertebroplasty: a report of 28 cases].

BACKGROUND & OBJECTIVE: Treating metastatic vertebral tumor is a common difficulty. Conservative treatment can't efficiently release the pain, and establish the spinal column; while operation may destroy normal tissue, and cause many complications, which would prolong the time of in-hospital, and delay the treatment of primary disease, at the same time, operation is not suitable for multiple metastatic spinal tumors. This study was designed to investigate the efficacy of percutaneous vertebroplasty (PVP) on metastatic spinal tumor under the guidance of digital subtraction angiography (DSA). METHODS: A total of 58 patients with metastatic spinal tumor were divided into 2 groups according to their intention, 28 (group A) were treated with PVP combined radiochemotherapy, 30 (group B) were treated with routine radiochemotherapy. Baselines of the 2 groups have no significant difference. Two months after treatment, the life quality, therapeutic response, stabilization of the vertebral column, and toxic effect were compared between group A and group B. RESULTS: After treatment, both groups showed significant changes in life quality, and therapeutic response (P < 0.05, t(1)=2.74, t(2)=11.74). Group A showed no complication. Group B showed 5 cases of pathologic constrictive fracture in spinal body. CONCLUSION: PVP is a simple and minimally invasive treatment with few complications, which can release pain, decrease incidence of pathologic constrictive fracture in spinal body, and improve life quality of patients with metastatic spinal tumor.

[Repair of large bone defect due to excision of bone tumor with bone allograft].

OBJECTIVE: To study the reparative and reconstructive methods for the large bone defect due to the excision of bone tumor. METHODS: According to the size and shape of the bone defect, we selected the proper bone and joint or manipulated bone segment of the profound hypothermia freezing allograft and gave locked intramedullary nails or steel plate and screws for stable internal fixation. RESULTS: In the 22 cases, 20 survived without tumor and 2 died. One patient treated with the allograft of semi-knee joint was found rejection. Then the wound did not heal. After the skin flap grafting was performed, the wound still did not heal, so the patient accepted amputation(4.5%). In the other 21 cases, the X-ray and 99mTc SPECT showed some callus or concentration of nuclein which implied bone union. According to Markin bone graft criterion, the excellent rate of function recovery was 81.8%. CONCLUSION: Allografting of bone and joint is a good and workable method in repairing and reconstructing the bone defect due to the excision of bone tumor. It should be further studied and be applied.