Effects of endostar combined multidrug chemotherapy in osteosarcoma

Endostatin in disease modulation: From cancer to beyond

Angiogenesis plays a pivotal role in various pathological conditions, making it a key target in therapeutic development. Anti-angiogenic therapies are gaining traction for their potential in treating a range of angiogenesis-dependent diseases. Among these, endogenous angiogenesis inhibitors, particularly endostatin, have garnered significant attention for their therapeutic potential. While extensively studied for its anti-angiogenic effects in cancer, endostatin also exhibits anti-atherosclerotic and anti-fibrotic properties, broadening its therapeutic scope. Despite the successful clinical use of recombinant human endostatin in China for nearly two decades, its broader therapeutic potential remains underexplored. Thus, this review delves into the multifaceted applications of endostatin, examining its role in ocular diseases, inflammation, reproductive disorders, and tumor angiogenesis. Furthermore, it provides a comprehensive overview of its emerging roles beyond angiogenesis, particularly in the context of atherosclerosis and fibroproliferative conditions.

RETRACTED: Poly (lactic-co-glycolic acid)-encapsulated Endostar-loaded calcium phosphate cement as anti-tumor bone cement for the treatment of bone metastasis in lung cancer

Lung cancer is one of the most common malignant tumors in the world. In approximately 30%-40% of lung cancer patients, bone metastases ensues with osteolytic destruction. Worse still, intractable pain, pathological fracture, and nerve compression caused by bone metastases are currently the bottleneck of research, diagnosis, and treatment of lung cancer. Therefore, the present study aims at investigating the effectiveness of a new composite material made of calcium phosphate cement (CPC) and Endostar on repairing bone defects in vitro and in vivo. As indicated in results, the mechanical properties of CPC+Endostar and CPC+PLGA+Endostar do not differ from those of pure CPC. The PLGA-embedded Endostar slow-release microspheres were designed and prepared, and were combined with CPC. Poly (lactic-co-glycolic acid (PLGA) is a biodegradable polymer material in vivo, so the effect on its mechanical properties is negligible. CPC+Endostar and CPC+PLGA+Endostar have been proved to inhibit cell proliferation, promote apoptosis and block cell cycle in G2 phase; the expression levels of osteoclast-related genes CXCL2, TGF-β1, IGF-1, IL-6, and RANKL were significantly decreased while osteogenic ability and alkaline phosphatase activity observably enhanced. In vivo studies have revealed that the expression levels of TRAP, RANKL, and Caspase3 in CPC+PLGA+ENDO-treated tumor tissues after 3 weeks were higher than those in other groups with the prolongation of animal treatment time, while the expression levels of OPN and BCL2 were lower than those in other groups. In hematoxylin and eosin and TUNEL staining, 3 weeks of CPC+PLGA+ENDO-treatment yielded higher tissue necrosis and apoptosis than other groups; computed tomography and magnetic resonance imaging results showed the posterior edge bone damage reduced as a result of the CPC+PLGA+ENDO grafting in vertebral pedicle. Overall, the feasibility and reliability of CPC-loaded Endostar in the treatment of bone metastasis in lung cancer were investigated in this study, so as to promote the basic research and treatment of bone metastasis in lung cancer and other malignant tumors.

Targeted anti-angiogenesis therapy for advanced osteosarcoma

To date, despite extensive research, the prognosis of advanced osteosarcoma has not improved significantly. Thus, patients experience a reduced survival rate, suggesting that a reevaluation of current treatment strategies is required. Recently, in addition to routine surgery, chemotherapy and radiotherapy, researchers have explored more effective and safer treatments, including targeted therapy, immunotherapy, anti-angiogenesis therapy, metabolic targets therapy, and nanomedicine therapy. The tumorigenesis and development of osteosarcoma is closely related to angiogenesis. Thus, anti-angiogenesis therapy is crucial to treat osteosarcoma; however, recent clinical trials found that it has insufficient efficacy. To solve this problem, the causes of treatment failure and improve treatment strategies should be investigated. This review focuses on summarizing the pathophysiological mechanisms of angiogenesis in osteosarcoma and recent advances in anti-angiogenesis treatment of osteosarcoma. We also discuss some clinical studies, with the aim of providing new ideas to improve treatment strategies for osteosarcoma and the prognosis of patients.

Generation and utilization of endostatin-sensitive cell lines for assessing the biological activity of endostatin

Recombinant proteins are gaining increasing popularity for treating human diseases. The clinical effectiveness of recombinant proteins is directly related to their biological activity, which is an important indicator in drug development and quality control. However, certain recombinant proteins have unclear or complex signal pathways, making detecting their activity in vitro difficult. For instance, recombinant human endostatin (endostatin), a new antitumor drug developed in China, lacks a sensitive and stable assay for its biological activity since being market approval. To address this issue, we performed a genome-wide screening of immortalized human umbilical vein endothelial cells (HUVECs) using a CRISPR/Cas9 knockout library containing 20,000 targeted genes. We identified two potential endostatin-resistant genes, NEPSPP and UTS2, and successfully constructed a highly sensitive cell line, HUVEC-UTS2-3#, by knocking down the UTS2 gene. Based on the optimized parameters of HUVEC-UTS2-3# cells, we established a new method for detecting the biological activity of endostatin. The method was validated, and it produced results consistent with primary HUVEC cells but with higher sensitivity and more stable data. The use of gene-editing technology provides a novel solution for detecting the biological activity of recombinant proteins that other methods cannot detect.

Recombinant human endostatin as a potential anti-angiogenic agent: therapeutic perspective and current status

Angiogenesis is the physiological process that results in the formation of new blood vessels develop from pre-existing vasculature and plays a significant role in several physiological and pathological processes. Inhibiting angiogenesis, a crucial mechanism in the growth and metastasis of cancer, has been proposed as a potential anticancer therapy. Different studies showed the beneficial effects of angiogenesis inhibitors either in patients suffering from different cancers, alone or in combination with conventional therapies. Even though there are currently a number of efficient anti-angiogenic drugs, including monoclonal antibodies and kinase inhibitors, the associated toxicity profile and their affordability constraints are prompting researchers to search for a safe and affordable angiostatic agent for cancer treatment. Endostatin is one of the endogenous anti-angiogenic candidates that have been extensively pursued for the treatment of cancer, but even over three decades after its discovery, we have not made much advancement in employing it as an anticancer therapeutic despite of its remarkable anti-angiogenic effect with low toxicity profile. A recombinant human endostatin (rh-Es) variant for non-small cell lung cancer was approved by China in 2006 and has since been used effectively. Several other successful clinical trials related to endostatin for various malignancies are either ongoing or have already been completed with promising results. Thus, in this review, we have provided an overview of existing anti-angiogenic drugs developed for cancer therapy, with a summary of tumour angiogenesis in the context of Endostatin, and clinical status of rh-Es in cancer treatment. Furthermore, we briefly discuss the various strategies to improve endostatin features (poor pharmacokinetic properties) for developing rh-Es as a safe and effective agent for cancer treatment.

Efficacy of Recombinant Human Endostatin plus Neoadjuvant Chemotherapy for Osteosarcoma and Its Influence on Serum VEGF and MMP-9 Levels

Objective

To investigate the efficacy of recombinant human endostatin (rh-Endo) plus neoadjuvant chemotherapy (NACT) for osteosarcoma (OSA) and its influence on serum vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9).

Methods

The case data of 141 OSA patients presented to the North District, Xiangyang Central Hospital Affiliated to Hubei University of Arts and Sciences from January 2018 to June 2019, were analyzed retrospectively. Patients receiving NACT (methotrexate + ifosfamide + adriamycin) were assigned into the control group (CNG; n = 65), while those treated with rh-Endo plus NACT were included in the combination group (CMG; n = 76). The following aspects were compared: clinical efficacy, serum tumor markers, serum VEGF and MMP-9 contents, inflammatory factors, incidence of adverse reactions, limb function scores at 6 months of follow-up, and prognostic quality of life (QOL).

Results

A statistically higher overall response rate (ORR) was determined in CMG versus CNG (84.2% vs. 64.6%, P < 0.05). The pretreatment serum bone alkaline phosphatase (BALP), insulin-like growth factor (IGF)-1, serum amyloid A (SAA), VEGF, MMP-9, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and interleukin (IL)-10 levels differed insignificantly between the two cohorts (P > 0.05); while except IL-10 that showed increased expression in both cohorts and was comparatively higher in CMG, the other 8 parameters reduced in both cohorts after 2 weeks of drug withdrawal, and the reduction of each parameter was more significant in CMG (P < 0.05). The total adverse reaction rate was 30.2% in CMG, which was higher than that of 36.9% in CNG, albeit without a statistical difference (P > 0.05). An evidently higher 2-year survival rate was determined in CMG (P < 0.05).

Conclusions

rh-Endo plus NACT is more effective than NACT alone in the treatment of osteosarcoma, which can validly restore the balance of vascular endothelial cells, reduce inflammation, and is worth promoting in clinic.

Multi-omics analysis based on 3D-bioprinted models innovates therapeutic target discovery of osteosarcoma

Current in vitro models for osteosarcoma investigation and drug screening, including two-dimensional (2D) cell culture and tumour spheroids (i.e. cancer stem-like cells), lack extracellular matrix (ECM). Therefore, results from traditional models may not reflect real pathological processes in genuine osteosarcoma histological structures. Here, we report a three-dimensional (3D) bioprinted osteosarcoma model (3DBPO) that contains osteosarcoma cells and shrouding ECM analogue in a 3D frame. Photo-crosslinkable bioinks composed of gelatine methacrylamide and hyaluronic acid methacrylate mimicked tumour ECM. We performed multi-omics analysis, including transcriptomics and DNA methylomics, to determine differences between the 3DBPO model and traditional models. Compared with 2D models and tumour spheroids, our 3DBPO model showed significant changes in cell cycle, metabolism, adherens junctions, and other pathways associated with epigenetic regulation. The 3DBPO model was more sensitive to therapies targeted to the autophagy pathway. We showed that simulating ECM yielded different osteosarcoma cell metabolic characteristics and drug sensitivity in the 3DBPO model compared with classical models. We suggest 3D printed osteosarcoma models can be used in osteosarcoma fundamental and translational research, which may contribute to novel therapeutic strategy discovery.

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3DBPO model behaved better than traditional 2D and CSC models in simulating in vivo osteosarcoma microenvironment.

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3DBPO model showed significant changes in many signaling pathways associated with epigenetic regulation.

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3DBPO model was particularly sensitive to autophagy-related drugs.

Research of the Active Components and Potential Mechanisms of Qingfei Gujin Decoction in the Treatment of Osteosarcoma Based on Network Pharmacology and Molecular Docking Technology

Aim

Qingfei Gujin Decoction (QGD) has been shown to be effective against osteosarcoma. This research was aimed at investigating the main active ingredients and potential mechanisms of QGD acting on osteosarcoma through network pharmacology and molecular docking techniques.

Methods

The active ingredients and targets of QGD were screened from the TCMSP database, and the predicted targets were obtained from the PharmMapper database. Meanwhile, the targets of osteosarcoma were collected using OMIM, PharmGKB, and DisGeNET databases. Then, GO and KEGG enrichment analyses were performed by RStudio. PPI and drug-ingredient-target networks were constructed using Cytoscape 3.2.1 to screen the major active ingredients, key networks, and targets. Finally, molecular docking of key genes and their regulatory active ingredients was performed using AutoDockTools 1.5.6 software.

Results

38 active ingredients were collected, generating 89 cross-targets; quercetin, luteolin, β-sitosterol, and kaempferol were the main active ingredients of QGD acting on osteosarcoma, and major signaling pathways such as PI3K-Akt signaling pathway, MAPK signaling pathway, and IL-17 signaling pathway were observed. TP53, SRC, and ESR1 were identified as key proteins that docked well with their regulated compounds.

Conclusion

QGD is effective against osteosarcoma through multicomponent, multitarget, and multipathway. This study was helpful for finding effective targets and compounds for osteosarcoma treatment.

Inhibition of Walker-256 Tumor Growth by Combining Microbubble-Enhanced Ultrasound and Endostar

OBJECTIVES

This research is to investigate the anti-tumor effects by combining anti-vascular effect of microbubble enhanced ultrasound (MEUS) mechanical destruction and anti-angiogenic effect of Endostar.

METHODS

Rats bearing Walker-256 tumor were randomly divided into 4 groups treated by Endostar + MEUS combination, Endostar, MEUS or Sham ultrasound (US), respectively. MEUS was induced by Sonazoid microbubble and a focused therapeutic US device. Contrast-enhanced ultrasound (CEUS) was used to assess tumor perfusion before and after treatment. Microvessel density (MVD) was evaluated with immunohistochemical staining of CD31, CD34, and VEGFA. TUNEL assay was used to determine the apoptosis rate of tumor cells.

RESULTS

Endostar + MEUS combined group induced the most reduced blood perfusion and most retarded tumor growth compared with other 3 groups. Decreased MVD was shown in Endostar + MEUS, Endostar and MEUS group, but the lowest MVD value was presented in the combined treatment group. Significant increase was observed in the combined therapy group and MEUS group.

CONCLUSIONS

This study showed an improved anti-vascular and anti-angiogenic effect achieved by combining Endostar and MEUS, and may provide a new method potential for anti-tumor therapy.

Chemotherapy Combined With Recombinant Human Endostatin (Endostar) Significantly Improves the Progression-Free Survival of Stage IV Soft Tissue Sarcomas

Purpose

Our previously study showed that recombinant human endostatin (Endostar) combined with chemotherapy had significant activity to increase the mPFS in patients with advanced sarcomas with tolerable side effects. However, the small cohort size and short follow-up time made it difficult to screen sensitive sarcoma subtypes and determine whether there is an overall survival benefit. With the largest sarcoma cohort to our knowledge, we try to confirm the efficacy and safety of chemotherapy combined with Endostar in stage IV sarcomas, with the specific purpose of finding out the sensitive sarcoma types for this combined treatment.

Methods

After the exclusion of ineligible patients, 156 patients with stage IV bone and soft tissue sarcomas were included in this study according to the inclusion criteria.

Results

By the end of follow-up, the ORR was 10.7% (9/84) vs 1.4% (1/72) (p=0.041), the DCR was 26.2% (22/84) vs 5.6% (4/72) (p=0.001) in the combined group and chemotherapy group, respectively. The mPFS of combined group was significantly longer than the chemotherapy group (10.42 vs 6.87 months, p=0.003). The mOS were 26.84 months and 23.56 months, without significant difference (p= 0.481). In osteogenic sarcoma, there was no statistically significant difference in the mPFS between the two groups (p=0.59), while in the soft tissue sarcoma, the mPFS in the combined group was significantly higher than that of the chemotherapy group (11.27 vs 8.05 months, p=0.004). Specifically, undifferentiated polymorphic sarcoma (UPS) was the possible sarcoma subtypes that benefited from the combined therapy. For the 38 UPS patients (28 patients in the combined group and 10 patients in the chemotherapy group), the mPFS in the combined group was up to 14.88 months, while it was only 7.1 months in the chemotherapy group, with a significant difference (p=0.006). The most common adverse events in the combined group were myelosuppression, gastrointestinal reactions and abnormal liver function, without significant difference in two groups.

Conclusion

Chemotherapy plus Endostar could prolong mPFS and improve ORR and DCR in patients with stage IV soft tissue sarcoma, suggesting that the combined therapy could improve the patient prognosis in soft tissue sarcomas, especially the UPS patients.

Current research progress in targeted anti-angiogenesis therapy for osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumour with a peak in incidence during adolescence. Delayed patient presentation and diagnosis is common with approximately 15% of OS patients presenting with metastatic disease at initial diagnosis. With the introduction of neoadjuvant chemotherapy in the 1970s, disease prognosis improved from 17% to 60%-70% 5-year survival, but outcomes have not significantly improved since then. Novel and innovative therapeutic strategies are urgently needed as an adjunct to conventional treatment modalities to improve outcomes for OS patients. Angiogenesis is crucial for tumour growth, metastasis and invasion, and its prevention will ultimately inhibit tumour growth and metastasis. Dysregulation of angiogenesis in bone microenvironment involving osteoblasts and osteoclasts might contribute to OS development. This review summarizes existing knowledge regarding pre-clinical and developmental research of targeted anti-angiogenic therapy for OS with the aim of highlighting the limitations associated with this application. Targeted anti-angiogenic therapies include monoclonal antibody to VEGF (bevacizumab), tyrosine kinase inhibitors (Sorafenib, Apatinib, Pazopanib and Regorafenib) and human recombinant endostatin (Endostar). However, considering the safety and efficacy of these targeted anti-angiogenesis therapies in clinical trials cannot be guaranteed at this point, further research is needed to completely understand and characterize targeted anti-angiogenesis therapy in OS.

A rapid response of lung squamous cell carcinoma following treatment with sintilimab combined with recombinant humane endostatin injection and nab-paclitaxel in an elderly patient: A case report

RATIONALE

At present, the prognosis of patients with giant lung squamous cell carcinoma (LSCC) is poor, and there is no safe and effective treatment for elderly patients with large LSCC.

PATIENT CONCERNS

Here, we reported a 77-year-old man admitted to the hospital with cough for 3 months and significant chest pain. Computed tomography (CT) imaging showed a large mass in the left lung with pleural effusion.

DIAGNOSES

Chest CT scan revealed a 12.5 cm × 7.3 cm mass in the left upper lobe adjacent to the pulmonary vein, with left pleural effusion. Pulmonary tumor markers were significantly elevated, and CT-guided percutaneous lung mass biopsy specimens showed LSCC.

INTERVENTIONS

After diagnosis, the patient was treated with sintilimab combined with endostar and nab-paclitaxel. After 2 cycles of treatment, the lung mass in the patient shrank rapidly and the clinical symptoms were relieved.

OUTCOMES

The patient's tumor dramatically shrank, and the pleural effusion was decreased after 4 cycles of treatment without any adverse effects. Meanwhile, the high-level tumor marker resumed normal.

LESSONS

Sintilimab combined with endostar and nab-paclitaxel may be a good treatment option for lung squamous cell cancer, especially for that in elderly patients.

The role of extracelluar matrix in osteosarcoma progression and metastasis

Osteosarcoma (OS) is the most common primary bone malignancy and responsible for considerable morbidity and mortality due to its high rates of pulmonary metastasis. Although neoadjuvant chemotherapy has improved 5-year survival rates for patients with localized OS from 20% to over 65%, outcomes for those with metastasis remain dismal. In addition, therapeutic regimens have not significantly improved patient outcomes over the past four decades, and metastases remains a primary cause of death and obstacle in curative therapy. These limitations in care have given rise to numerous works focused on mechanisms and novel targets of OS pathogenesis, including tumor niche factors. OS is notable for its hallmark production of rich extracellular matrix (ECM) of osteoid that goes beyond simple physiological growth support. The aberrant signaling and structural components of the ECM are rich promoters of OS development, and very recent works have shown the specific pathogenic phenotypes induced by these macromolecules. Here we summarize the current developments outlining how the ECM contributes to OS progression and metastasis with supporting mechanisms. We also illustrate the potential of tumorigenic ECM elements as prognostic biomarkers and therapeutic targets in the evolving clinical management of OS.

Recombined humanized endostatin (Endostar) intravenous infusion in the treatment of refractory nasopharyngeal carcinoma: Three case reports

RATIONALE

Refractory nasopharyngeal carcinoma is challenging to treat and at present there is no standard treatment or any good choice.

PATIENT CONCERNS

Although the three patients in our case reports had already underwent multiple treatments before, they still suffered from disease recurrence of nasopharyngeal carcinoma.

DIAGNOSIS

They were diagnosed as refractory nasopharyngeal carcinoma.

INTERVENTIONS

A continuous infusion of Endostar, an antiangiogenic agent, combined with chemotherapy and radiation therapy was given to treat the patients.

OUTCOMES

Patients showed complete or partial response to the combined therapy as evidenced by regression of tumors and decrease in plasma Epstein-Barr virus (EBV) DNA load.

LESSONS

Continuous infusions of Endostar in combination with chemotherapy and/or radiation therapy showed promising efficacy and safety. The combination therapy indicates a new approach to treat refractory nasopharyngeal carcinoma.

Endostar regulates EMT, migration and invasion of lung cancer cells through the HGF-Met pathway

AIM

Though Endostar (ES) could inhibit tumor growth by inhibiting tumor angiogenesis, other possible mechanisms have been less reported. This study aims to investigate the role of ES in the treatment of lung cancer from the perspective of macrophage-mediated epithelial mesenchymal transformation (EMT).

METHODS

THP1 cells were induced to polarized macrophages (MΦ). A549 and H1795 cells were separately treated with MΦ conditioned medium, ES (12.5 μg/ml) and HGF (5 ng/ml) for 24 h at 37 °C. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of CCL17, CD163, hepatocyte growth factor (HGF), Epidermal Growth Factor (EGF), transforming growth factor (TGF)-β1 and interleukin (IL)-6. Western blot was carried out to detect the p-MET, MET and EMT-related proteins (E-cadherin, N-cadherin, Snail and vimentin). Fibroblast-like A549 and H1975 cells were observed by a microscope. Cell invasion and migration were observed and analyzed by transwell and scratch assays.

RESULTS

The expression levels of CCL17 and CD163 were significant higher in MΦ. ES significantly inhibited the expression of HGF in MΦ. Moreover, ES could restore the abnormal expressions of EMT-related proteins and inhibit MΦ-induced and HGF-induced fibroblast-like lung cancer cells. Furthermore, ES suppressed the MΦ-induced and HGF-induced migration and invasion of lung cancer cells. ES was also found to down-regulate HGF-Met signaling in HGF-treated lung cancer cells.

CONCLUSION

ES suppresses lung cancer progression by down-regulating HGF-Met signaling, revealing the possible mechanism of ES in the process of treating lung cancer patients.

Ultrasound-targeted microbubble destruction improved the antiangiogenic effect of Endostar in triple-negative breast carcinoma xenografts

PURPOSE

Ultrasound-targeted microbubble destruction (UTMD) has been reported to be a meritorious technique for drug targeting delivery. In this study, we aimed to evaluate the synergistic antiangiogenic effect of UTMD combined with Endostar on triple-negative breast carcinoma tumors.

MATERIALS AND METHODS

The lipid-shelled microbubbles (MBs) conjugated with Endostar were constructed using a biotin-avidin bridging chemistry method, and the morphological characteristics and drug-conjugating content were determined. MBs were administered intravenously to nude mice bearing MDA-MB-231 breast carcinoma xenografts and ultrasound exposure followed. The tumor microcirculation was observed by contrast-enhanced ultrasonography (CEUS) and the Endostar biodistribution was detected by enzyme-linked immunosorbent assay. Twenty-four breast carcinoma-bearing nude mice were divided into four groups. After treatment, every 3 days for 15 days the in vivo antitumor effects were assessed by calculating the tumor growth inhibition rate (TGIR). The tumor microcirculation was observed by CEUS, the tumor microvessel density (MVD) was calculated by immunohistochemistry under a microscope, and the vascular endothelial growth factor (VEGF) gene expression was detected by real-time quantitative polymerase chain reaction.

RESULTS

The prepared Endostar-conjugated MBs were round and well-dispersed with a mean size of 2.8 ± 0.7 µm and a drug conjugating content of 800.72 ± 70.53 µg/108 MBs. UTMD blocked the tumor microcirculation, and improved Endostar release in the targeted tumor tissue with a drug content of 1.12 ± 0.43 µg/gram protein, which was about three times higher than that in Endostar group or Endostar conjugated MBs group. Endostar-conjugated MBs combined with UTMD treatment achieved the optimal antitumor effects in vivo with a TGIR of 46.29%, and apparent antiangiogenic effects with minimal tumor blood perfusion, MVD and VEGF gene expression level.

CONCLUSION

UTMD can improve Endostar delivery in the targeting tumor tissue and mediate synergistic antiangiogenetic and antitumor effects, which may be a potential therapeutic strategy for refractory breast cancer.

APE1 stimulates EGFR-TKI resistance by activating Akt signaling through a redox-dependent mechanism in lung adenocarcinoma

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become the standard first-line treatment for advanced lung adenocarcinoma (LUAD) cancer patients with activating EGFR mutations. However, most patients show acquired resistance to EGFR-TKIs, thereby resulting in a modest overall survival benefit. Here, we found that expression level of APE1 was closely associated with TKI resistance in LUAD. Our clinical data show that level of APE1 was inversely correlated with progression-free survival rate and median time to progression in EGFR-mutated LUAD patients. Additionally, we observed increased expression of APE1 in TKI-resistant LUAD cell lines compared to their parental cell lines. Overexpression of APE1-protected TKI-sensitive LUAD cells from TKI-induced cell growth inhibition and cell death. In contrast, inhibition of APE1-enhanced TKI-induced apoptosis, cell growth inhibition and tumor growth inhibition in TKI-resistant LUAD. In addition, we identified that APE1 positively regulates Akt activation and APE1 overexpression-induced TKI resistance was attenuated by inhibition of Akt activity. Finally, we demonstrated that inhibition of the redox function of APE1 enhances the sensitivity of TKI-resistant LUAD cells to TKI treatment and inhibits Akt phosphorylation in TKI-resistant LUAD cells, but not by inhibition of the APE1 DNA repair function. Taken together, our data show that increased expression of APE1 significantly contributes to TKI resistance development in LUAD, and targeting APE1 may reverse acquired resistance of LUAD cells to TKI treatment. Additionally, our data show that APE1 regulates TKI resistance in LUAD cells by activating Akt signaling through a redox-dependent mechanism.

Progress in the chemotherapeutic treatment of osteosarcoma

Osteosarcoma (OS) is the most common type of primary bone tumor in children and adolescents and has been associated with a high degree of malignancy, early metastasis, rapid progression and poor prognosis. However, the use of adjuvant chemotherapy improves the prognosis of patients with OS. OS chemotherapy is based primarily on the use of adriamycin, cisplatin (DDP), methotrexate (MTX), ifosfamide (IFO), epirubicin (EPI) and other drugs. Previous studies have revealed that the survival rate for patients with OS appears to have plateaued: 5-year survival rates remain close to 60%, even with the use of combined chemotherapy. The most limiting factors include complications and fatal toxicity associated with chemotherapy agents, particularly high-dose MTX (HD-MTX), for which high toxicity and great individual variation in responses have been observed. Docetaxel (TXT) is a representative member of the relatively recently developed taxane class of drugs, which function to inhibit OS cell proliferation and induce apoptosis. Recently, more clinical studies have reported that TXT combined with gemcitabine (GEM) is effective in the treatment of OS (relapse/refractory and progressive), providing evidence in support of potential novel treatment strategies for this patient population. However, there is still no global consensus on this type of chemotherapy approach. The present review summarizes current studies surrounding progress in the chemotherapeutic treatment of OS and discusses the advantages and potential feasibility of TXT+GEM in the treatment of OS.

Current Status and Study Progress of Recombinant Human Endostatin in Cancer Treatment

Angiogenesis plays fundamentally critical roles in solid-tumor pathogenesis, growth, invasion and metastasis. Endostatin, one of the most potent anti-angiogenic factors, was first isolated in Folkman's lab in 1997, and was reported to dramatically shrink tumor blood formation. But its insoluble and unstable nature coupled with the high cost of synthesizing the endostatin protein doomed it for clinical cancer treatment. Intrigued by Folkman's pioneering discoveries, Chinese scientists found a way to refold the protein, making it cost-effective to manufacture a recombinant human endostatin, a soluble and stable form of endostatin. A number of clinical studies have demonstrated the significant survival benefit of rh-endostatin in treating late stage non-small-cell lung carcinoma (NSCLC) and, as a result, rh-endostatin (Endostar®) was approved by the State Food and Drug Administration of China (CFDA) in September of 2005 as a treatment option for NSCLC. Since then, increasing bodies of clinical data and experience have been obtained from a variety of other different cancers, such as small cell lung cancer, NSCLC in other settings, including malignant serous effusion, melanoma, colon cancer, gastric cancer, breast cancer, nasopharyngeal cancers, and others. This review aims at summarizing current clinical data of rh-endostatin including its survival benefits, optimized dosages, routes of administration, recommended duration and frequency of treatment, predictive biomarkers, and its safety profile in lung cancers as well as other cancers.

Recombined humanized endostatin (Endostar) combined with chemotherapy for advanced bone and soft tissue sarcomas in stage IV

PURPOSE

This retrospective case-series study evaluated efficacy and safety of Endostar combined with chemotherapy in the treatment of advanced bone and soft tissue sarcomas in stage IV.

MATERIALS AND METHODS

Forty-seven patients diagnosed with stage IV bone and soft tissue sarcomas and treated with chemotherapy in Tianjin Medical University Cancer Institute & Hospital were reviewed. Of these patients, 23 patients were treated with Endostar plus chemotherapy (designated as combined group), and 24 patients received only chemotherapy (designated as control group). Progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and clinical benefit response (CBR) were analyzed to find the difference between these two groups with the purpose to investigate the role of Endostar in metastatic sarcomas.

RESULTS

Endostar combined with chemotherapy had significantly increased PFS. In the combined group and control groups, the median PFS (8.6 months versus 4.4 months) and the CBR (47.8% versus 16.7%) showed significant difference (P = 0.032), while the median overall survival (11.7 months versus 10.6 months, P = 0.658) and the ORR (17.4% versus 8.3%, P = 0.167) showed no significant difference. The common grade 3-4 side effects for both groups were myelosuppression and transient elevation of transaminases.

CONCLUSION

Endostar combined with chemotherapy had significant activity to increase the PFS and improve CBR in patients with advanced sarcomas, with tolerable side effects.

miR-491 Inhibits Osteosarcoma Lung Metastasis and Chemoresistance by Targeting αB-crystallin

Dysregulated microRNAs (miRNAs) play an important role in osteosarcoma (OS) progression. In the present study, we investigate the clinical significance of serum miR-491 level and the potential role of miR-491 in OS lung metastasis and chemoresistance. Clinical data show that the level of miR-491 was decreased in serum from OS patients compared with healthy control subjects, and that a decreased serum miR-491 level is correlated with increased metastasis, poor chemoresponse, and lower survival rate in OS patients. In vitro and in vivo experiments show that overexpression of miR-491 suppresses OS cell lung metastasis, whereas it enhances cisplatin (CDDP)-induced tumor growth inhibition and apoptosis. In contrast, inhibition of miR-491 stimulates OS cell lung metastasis and suppresses CDDP-induced tumor growth inhibition and apoptosis. Furthermore, we demonstrate that miR-491 exerts its role by directly targeting αB-crystallin (CRYAB) in OS. Our findings suggest that serum level of miR-491 has potential as a biomarker for predicting OS progression and prognosis of OS patients. Additionally, restoration of miR-491 may be a novel strategy for inhibiting OS lung metastasis and overcoming OS cell resistance to chemotherapy.

miR-135b Stimulates Osteosarcoma Recurrence and Lung Metastasis via Notch and Wnt/β-Catenin Signaling

Cancer stem cells (CSCs) play an important role in osteosarcoma (OS) metastasis and recurrence, and both Wnt/β-catenin and Notch signaling are essential for the development of the biological traits of CSCs. However, the mechanism that underlies the simultaneous hyperactivation of both Wnt/β-catenin and Notch signaling in OS remains unclear. Here, we report that expression of miR-135b correlates with the overall and recurrence-free survival of OS patients, and that miR-135b has an activating effect on both Wnt/β-catenin and Notch signaling. The overexpression of miR-135b simultaneously targets multiple negative regulators of the Wnt/β-catenin and Notch signaling pathways, including glycogen synthase kinase-3 beta (GSK3β), casein kinase 1a (CK1α), and ten-eleven translocation 3 (TET3). Therefore, upregulated miR-135b promotes CSC traits, lung metastasis, and tumor recurrence in OS. Notably, antagonizing miR-135b potently inhibits OS lung metastasis, cancer cell stemness, CSC-induced tumor formation, and recurrence in xenograft animal models. These findings suggest that miR-135b mediates the constitutive activation of Wnt/β-catenin and Notch signaling, and that the inhibition of miR-135b is a novel strategy to inhibit tumor metastasis and prevent CSC-induced recurrence in OS.

Proliferation, Apoptosis and Invasion effects of mistletoe alkali on human osteosarcoma U2OS in vitro

OBJECTIVE

To evaluate the effects of mistletoe alkali on human Osteosarcoma cells (U2OS) in vitro.

SUMMARY OF BACKGROUND DATA

Osteosarcoma is the most common primary malignant tumor of bone tumor, although there are a lot of therapies such as surgery, radiotherapy and chemotherapy, its prognosis is still very poor. There is increasing interest in the protective biological function of natural antioxidants contained in Chinese medicinal herbs, which are candidates for the prevention of tumors. Mistletoe alkali is one of the compounds extracted from Viscum coloratum (Komar.) Nakai, one kind of mistletoe, whose extracts contribute to the improvement of the prognosis of patients with malignancies.

METHODS

The effect of mistletoe alkali on the growth of U2OS cells was compared with 5-FU, using a Cell Counting Kit-8 (CCK-8). The influence of mistletoe alkali on U2OS's proliferation and apoptosis were tested by TUNEL staining and immunocytochemical (ICC) staining of caspase 3 and proliferating cell nuclear antigen (PCNA). Additionally, the invasion ability of U2OS cells was detected using a Boyden chamber trans-well migration assay.

RESULTS

CCK-8 assays gave an IC50 of 7μg/ml for mistletoe alkali. Compared to 5-FU, mistletoe alkali inhibited U2OS proliferation and induced apoptosis more effectively. The invasion ability of U2OS was also weaker in mistletoe alkali than in 5-FU.

CONCLUSIONS

Mistletoe alkali significantly inhibited growth and invasion abilities of U2OS cells and induced their apoptosis in vitro. Mistletoe alkali may be a more effective drug for Human Osteosarcoma than the standard chemotherapeutic drug 5-FU.

Metastatic osteosarcoma: a challenging multidisciplinary treatment

Osteosarcoma is the most common malignant bone tumor, currently treated with pre-and postoperative chemotherapy in association with the surgical removal of the tumor. About 15-20% of patients have evidence of metastases at diagnosis, mostly in the lungs. Patients with metastatic disease still have a very poor prognosis, with approximately 20-30% of long-term survivors, as compared with 65-70% of patients with localized disease. The optimum management of these patients has not been standardized yet due to several patterns of metastatic disease harboring different prognosis. Complete surgical resection of all sites of disease is mandatory and predictive of survival. Patients with multiple sites of disease not amenable to complete surgery removal should be considered for innovative therapeutic approaches because of poor prognosis.

In vitro cancer cell-ECM interactions inform in vivo cancer treatment

The general progression of cancer drug development involves in vitro testing followed by safety and efficacy evaluation in clinical trials. Due to the expense of bringing candidate drugs to trials, in vitro models of cancer cells and tumor biology are required to screen drugs. There are many examples of drugs exhibiting cytotoxic behavior in cancer cells in vitro but losing efficacy in vivo, and in many cases, this is the result of poorly understood chemoresistant effects conferred by the cancer microenvironment. To address this, improved methods for culturing cancer cells in biomimetic scaffolds have been developed; along the way, a great deal about the nature of cancer cell-extracellular matrix (ECM) interactions has been discovered. These discoveries will continue to be leveraged both in the development of novel drugs targeting these interactions and in the fabrication of biomimetic substrates for efficient cancer drug screening in vitro.

A high risk of osteosarcoma in individuals who are homozygous for the p.D104N in endostatin

The D104N polymorphism (p.D104N) in endostatin has been previously identified in many types of cancer, and this polymorphism is believed to be a phenotypic modulator in some tumors. However, it is unknown whether endostatin p.D104N affects the risk and progression of osteosarcoma (OS). Here, we analyzed the p.D104N endostatin variant in 236 patients with OS and 418 healthy individuals. Similar frequencies of wild type and heterozygous p.104DN endostatin were observed in controls and OS patients. Interestingly, the frequency of the homozygous p.D104N (p.104NN) genotype was higher in OS patients group compared to control group, suggesting that individuals with p.104NN endostatin have a significantly increased risk for OS. In addition, OS patients with p.104NN endostatin had a shorter survival time and a higher rate of metastasis than OS patients with wild type endostatin. Animal experiments revealed that overexpression of p.104NN endostatin did not significantly inhibit OS lung metastasis. Interestingly, administration of endostatin dramatically inhibited OS lung metastasis in the p.104NN endostatin xenograft model. Together, these results suggest that p.104NN of endostatin is associated with the risk of OS and demonstrates predictive significance for clinical outcome in OS patients. In addition, endostatin therapy may be necessary for OS patients harboring p.104NN endostatin.

Advances in emerging drugs for osteosarcoma

INTRODUCTION

Osteosarcoma (OS), the most common primary malignant bone tumor, is currently treated with pre- and postoperative chemotherapy in association with the surgical removal of the tumor. Conventional treatments allow to cure about 60 - 65% of patients with primary tumors and only 20 - 25% of patients with recurrent disease. New treatment approaches and drugs are therefore highly warranted to improve prognosis.

AREAS COVERED

This review focuses on the therapeutic approaches that are under development or clinical evaluation in OS. Information was obtained from different and continuously updated data bases, as well as from literature searches, in which particular relevance was given to reports and reviews on new targeted therapies under clinical investigation in high-grade OS.

EXPERT OPINION

OS is a heterogeneous tumor, with a great variability in treatment response between patients. It is therefore unlikely that a single therapeutic tool will be uniformly successful for all OS patients. This claims for the validation of new treatment approaches together with biologic/(pharmaco)genetic markers, which may select the most appropriate subgroup of patients for each treatment approach. Since some promising novel agents and treatment strategies are currently tested in Phase I/II/III clinical trials, we may hope that new therapies with superior efficacy and safety profiles will be identified in the next few years.

A Gelatinases-targeting scFv-based Fusion Protein Shows Enhanced Antitumour Activity with Endostar against Hepatoma

Gelatinases play important roles in tumour invasion and metastasis and are thus considered promising targets for cancer therapy. In this study, a new single-chain variable fragment (scFv)-based fusion protein Fv-LDP, composed of the anti-gelatinases scFv and lidamycin apoprotein (LDP), was prepared, and its combination with angiogenesis inhibitor Endostar was then investigated. The fusion protein Fv-LDP specifically bound to various tumour cells, and its binding capability to human pulmonary giant cell carcinoma (PG) cells was higher than that of LDP. Fv-LDP inhibited the expression and secretion of gelatinases and could be internalized into tumour cells via endocytosis. Fv-LDP also suppressed the growth of human hepatoma cells and murine hepatoma 22 transplanted in Kunming mice in various degrees. In addition, Endostar could enhance the synergistic or additive inhibition of Fv-LDP on the growth, migration or invasion of human hepatoma cells shown by a colony formation assay and a transwell-based migration or invasion assay, respectively. In vivo, Fv-LDP/Endostar combination showed a significantly synergistic effect on the growth of a human hepatoma xenograft, with an inhibition rate of 80.8% compared with the Fv-LDP (44.1%) or Endostar (8.9%)-treated group. The above-mentioned results indicate that the fusion protein Fv-LDP is effective against transplantable hepatoma in mice and human hepatoma xenografts in athymic mice. Moreover, Endostar can potentiate the inhibition effect of Fv-LDP on the growth of human hepatoma cells and xenografts. These data will provide a new combined strategy for improving the therapeutic efficacy of treatments for hepatoma or other gelatinase-overexpressing tumours.

Evaluation of efficacy of anti-angiogenesis therapy for VX2 hepatic tumors in rabbits by spectral CT and CT perfusion imaging

AIM: To explore the efficacy of anti-angiogenesis therapy for VX2 hepatic tumors in rabbits by spectral computed tomography (CT) imaging and CT perfusion imaging.

METHODS: Sixty New Zealand white rabbits with implanted VX2 hepatic tumors were randomly divided into two groups (A and B), with each group containing 30 rabbits. On day 14 after tumor implantation, group B received intravenous endostatin at a dose of 3 mg/kg for 7 d. Both groups underwent spectral CT and CT perfusion scans on day 21 after tumor implantation. The animals were then sacrificed, and the expression of VEGF mRNA and FGF2 protein in the tumor rim (TR) and the normal region (NR) was detected by RT-PCR and Western blot, respectively.

RESULTS: For CT perfusion parameters, group A showed increased blood flow (BF), blood volume (BV), permeability surface (PS) and hepatic arterial fraction (HAF) and decreased mean transit time (MTT) in the TR compared with NR (P < 0.05). From days 14 to 21, BF and PS showed an increasing trend, while MTT decreased with tumor growth (P < 0.05). The standardization of iodine (NIC) during arterial phase of the TR and NR exhibited a statistically significant difference (P < 0.05). The NIC of the TR during the arterial phase was significantly higher on day 21 than on day 14. Compared with group A on day 21, BF, BV, PS and HAF decreased, and MTT increased in group B. Pearson correlation analysis showed that these parameters were positively correlated with VEGF mRNA and FGF2 protein expression.

CONCLUSION: Spectral imaging and CT perfusion imaging can provide hemodynamic information of liver lesions and quantitatively reflect the efficacy of anti-angiogenesis therapy.

The angiogenic asset of soft tissue sarcomas: a new tool to discover new therapeutic targets

STS (soft tissue sarcomas) are rare malignant tumours deriving from cells of mesenchymal origin and represent only 1% of all malignant neoplasms. It has been extensively demonstrated that angiogenesis has an important role in cancer malignancy. Particularly, a lot of studies demonstrate the importance of angiogenesis in the development of carcinomas, whereas little is known about the role of angiogenesis in sarcomas and especially in STS. This review aims at summarizing the new discoveries about the nature and the importance of angiogenesis in STS and the new possible therapeutic strategies involved. Only a few studies concerning STS focus on tumour neovascularization and proangiogenic factors and look for a correlation with the patients prognosis/survival. These studies demonstrate that intratumoural MVD (microvessels density) may not accurately represent the angiogenic capacity of STS. Nevertheless, this does not exclude the possibility that angiogenesis could be important in STS. The importance of neoangiogenesis in soft tissue tumours is confirmed by the arising number of publications comparing angiogenesis mediators with clinical features of patients with STS. The efficacy of anti-angiogenic therapies in other types of cancer is well documented. The understanding of the involvement of the angiogenic process in STS, together with the necessity to improve the therapy for this often mortal condition, prompted the exploration of anti-tumour compounds targeting this pathway. In conclusion, this review emphasizes the importance to better understand the mechanisms of angiogenesis in STS in order to subsequently design-specific target therapies for this group of poorly responding tumours.

Anti-tumor effect of a novel soluble recombinant human endostatin: administered as a single agent or in combination with chemotherapy agents in mouse tumor models

Background

Angiogenesis has become an attractive target in cancer treatment. Endostatin is one of the potent anti-angiogenesis agents. Its recombinant form expressed in the yeast system is currently under clinical trials. Endostatin suppresses tumor formation through the inhibition of blood vessel growth. It is anticipated that combined therapy using endostatin and cytotoxic compounds may exert an additive effect. In the present study, we expressed and purified recombinant human endostatin (rhEndostatin) that contained 3 additional amino acid residues (arginine, glycine, and serine) at the amino-terminus and 6 histidine residues in its carboxyl terminus. The recombinant protein was expressed in E. Coli and refolded into a soluble form in a large scale purification process. The protein exhibited a potent anti-tumor activity in bioassays. Furthermore, rhEndostatin showed an additive effect with chemotherapy agents including cyclophosphamide (CTX) and cisplatin (DDP).

Methods

rhEndostatin cDNA was cloned into PQE vector and expressed in E. Coli. The protein was refolded through dialysis with an optimized protocol. To establish tumor models, nude mice were subcutaneously injected with human cancer cells (lung carcinoma A549, hepatocellular carcinoma QGY-7703, or breast cancer Bcap37). rhEndostatin and/or DDP was administered peritumorally to evaluate the rate of growth inhibition of A549 tumors. For the tumor metastasis model, mice were injected intravenously with mouse melanoma B16 cells. One day after tumor cell injection, a single dose of rhEndostatin, or in combination with CTX, was administered intravenously or at a site close to the tumor.

Results

rhEndostatin reduced the growth of A549, QGY-7703, and Bcap37 xenograft tumors in a dose dependent manner. When it was administered peritumorally, rhEndostatin exhibited a more potent inhibitory activity. Furthermore, rhEndostatin displayed an additive effect with CTX or DDP on the inhibition of metastasis of B16 tumors or growth of A549 tumors.

Conclusion

Soluble rhEndostatin exhibits a potent anti-tumor activity in mouse xenograft models and it also has an additive effect with CTX and DDP, implying possible applications in clinical settings.

Improved survival in osteosarcoma patients with atypical low vascularization

BACKGROUND

Osteosarcoma is considered a highly vascularized bone tumor with early metastatic dissemination through intratumoral blood vessels mostly into the lung. Novel targets for therapy such as tumor vascularization are highly warranted since little progress has been achieved in the last 30 years. However, proof of relevance for vascularization as a major prognostic parameter has been hampered by tumor heterogeneity, difficulty in detecting microvessels by immunohistochemistry, and small study cohorts. Most recently, we demonstrated that highly standardized whole-slide imaging could overcome these limitations (Kunz et al., PloS One 9(3):e90727, 2014). In this study, we applied this method to a multicenter cohort of 131 osteosarcoma patients to test osteosarcoma vascularization as a prognostic determinant.

METHODS

Computer-assisted whole-slide analysis, together with enzymatic epitope retrieval, was used for CD31-based microvessel quantification in 131 pretreatment formalin-fixed and paraffin-embedded biopsies from three bone tumor centers. Kaplan-Meier-estimated survival and chemoresponse were determined and multivariate analysis was performed. Conventional hot-spot-based microvessel density (MVD) determination was compared with whole-slide imaging.

RESULTS

We detected high estimated overall (p ≤ 0.008) and relapse-free (p ≤ 0.004) survival in 25 % of osteosarcoma patients with low osteosarcoma vascularization in contrast to other patient groups. Furthermore, all patients with low osteosarcoma vascularization showed a good response to neoadjuvant chemotherapy. Comparison of conventional MVD determination with whole-slide imaging suggests false high quantification or even exclusion of samples with low osteosarcoma vascularization due to difficult CD31 detection in previous studies.

CONCLUSION

Low intratumoral vascularization at the time of diagnosis is a strong predictor for prolonged survival and good response to neoadjuvant chemotherapy in osteosarcoma.

Osteosarcoma microenvironment: whole-slide imaging and optimized antigen detection overcome major limitations in immunohistochemical quantification

BACKGROUND

In osteosarcoma survival rates could not be improved over the last 30 years. Novel biomarkers are warranted to allow risk stratification of patients for more individual treatment following initial diagnosis. Although previous studies of the tumor microenvironment have identified promising candidates, novel biomarkers have not been translated into routine histopathology. Substantial difficulties regarding immunohistochemical detection and quantification of antigens in decalcified and heterogeneous osteosarcoma might largely explain this translational short-coming. Furthermore, we hypothesized that conventional hot spot analysis is often not representative for the whole section when applied to heterogeneous tissues like osteosarcoma. We aimed to overcome these difficulties for major biomarkers of the immunovascular microenvironment.

METHODS

Immunohistochemistry was systematically optimized for cell surface (CD31, CD8) and intracellular antigens (FOXP3) including evaluation of 200 different antigen retrieval conditions. Distribution patterns of these antigens were analyzed in formalin-fixed and paraffin-embedded samples from 120 high-grade central osteosarcoma biopsies and computer-assisted whole-slide analysis was compared with conventional quantification methods including hot spot analysis.

RESULTS

More than 96% of osteosarcoma samples were positive for all antigens after optimization of immunohistochemistry. In contrast, standard immunohistochemistry retrieved false negative results in 35-65% of decalcified osteosarcoma specimens. Standard hot spot analysis was applicable for homogeneous distributed FOXP3+ and CD8+ cells. However, heterogeneous distribution of vascular CD31 did not allow reliable quantification with hot spot analysis in 85% of all samples. Computer-assisted whole-slide analysis of total CD31- immunoreactive area proved as the most appropriate quantification method.

CONCLUSION

Standard staining and quantification procedures are not applicable in decalcified formalin-fixed and paraffin-embedded samples for major parameters of the immunovascular microenvironment in osteosarcoma. Whole-slide imaging and optimized antigen retrieval overcome these limitations.

Osteosarcoma: Diagnostic dilemmas in histopathology and prognostic factors

Osteosarcoma (OS), the commonest malignancy of osteoarticular origin, is a very aggressive neoplasm. Divergent histologic differentiation is common in OS; hence triple diagnostic approach is essential in all cases. 20% cases are atypical owing to lack of concurrence among clinicoradiologic and pathologic features necessitating resampling. Recognition of specific anatomic and histologic variants is essential in view of better outcome. Traditional prognostic factors of OS do stratify patients for short term outcome, but often fail to predict their long term outcome. Considering the negligible improvement in the patient outcome during the last 20 years, search for novel prognostic factors is in progress like ezrin vascular endothelial growth factor, chemokine receptors, dysregulation of various micro ribonucleic acid are potentially promising. Their utility needs to be validated by long term followup studies before they are incorporated in routine clinical practice.