Prognostic significance of CD44V6 expression in osteosarcoma: a meta-analysis

Chimeric antigen receptor T cells in the treatment of osteosarcoma (Review)

Osteosarcoma (OS) is a frequently occurring primary bone tumor, mostly affecting children, adolescents and young adults. Before 1970, surgical resection was the main treatment method for OS, but the clinical results were not promising. Subsequently, the advent of chemotherapy has improved the prognosis of patients with OS. However, there is still a high incidence of metastasis or recurrence, and chemotherapy has several side effects, thus making the 5‑year survival rate markedly low. Recently, chimeric antigen receptor T (CAR‑T) cell therapy represents an alternative immunotherapy approach with significant potential for hematologic malignancies. Nevertheless, the application of CAR‑T cells in the treatment of OS faces numerous challenges. The present review focused on the advances in the development of CAR‑T cells to improve their clinical efficacy, and discussed ways to overcome the difficulties faced by CAR T‑cell therapy for OS.

Overall review of curative impact and barriers of CAR-T cells in osteosarcoma

Osteosarcoma (OS) is a rare form of cancer and primary bone malignancy in children and adolescents. Current therapies include surgery, chemotherapy, and amputation. Therefore, a new therapeutic strategy is needed to dramatically change cancer treatment. Recently, chimeric antigen receptor T cells (CAR-T cells) have been of considerable interest as it has provided auspicious results and patients suffering from low side effects after injection that resolve with current therapy. However, there are reports that cytokine release storm (CRS) can be observed in some patients. In addition, as researchers have faced problems that limit and suppress T cells, further studies are required to resolve these problems. In addition, to maximize the therapeutic benefit of CAR-T cell therapy, researchers have suggested that combination therapy could be better used to treat cancer by overcoming any problems and reducing side effects as much as possible. This review summarizes these problems, barriers, and the results of some studies on the evaluation of CAR-T cells in patients with osteosarcoma.

Prognostic value of CD44 expression in oral squamous cell carcinoma: A meta-analysis

CD44 as a marker of cancer stem cells (CSCs) may be correlated with tumor growth, cell migration, metastasis and chemo-radiotherapy resistance of cancers. However, the prognostic value of CD44 in oral squamous cell carcinoma(OSCC) remains controversial. Therefore, the purpose of the current study was to evaluate the correlation of CD44 expression with the prognosis of OSCC through a meta-analysis. We systematically searched PubMed, Scopus, ISI Web of Science, Embase and Cochrane Central databases for relevant studies up to November 2022. We included 11 articles with immunohistochemistry (IHC) method involving 1084 OSCC patients. Hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were calculated to assess the association between CD44 expression and overall survival (OS) and disease-free survival (DFS). Results showed that high expression of CD44 was a poor prognostic marker for OS in OSCC patients (HR: 1.71, 95 % CI: 1.18-2.47). Also results for DFS demonstrated that in patients with high CD44 expression who received treatment, the probability of tumor recurrence or death was 1.66 times and in the worst case this ratio can reach 2.39 (HR: 1.66, 95 % CI: 1.15-2.39). High CD44 expression associated with metastasis to lymph nodes and distant metastasis, poorer survival of the patients, tumor recurrence, higher tumor stage and grade and aggressive clinicopathological features. Therefore CD44 can be used as a valuable independent marker in predicting the prognosis of OSCC patients.

The Hyaluronan/CD44 Axis: A Double-Edged Sword in Cancer

Hyaluronic acid (HA) receptor CD44 is widely used for identifying cancer stem cells and its activation promotes stemness. Recent evidence shows that overexpression of CD44 is associated with poor prognosis in most human cancers and mediates therapy resistance. For these reasons, in recent years, CD44 has become a treatment target in precision oncology, often via HA-conjugated antineoplastic drugs. Importantly, HA molecules of different sizes have a dual effect and, therefore, may enhance or attenuate the CD44-mediated signaling pathways, as they compete with endogenous HA for binding to the receptors. The magnitude of these effects could be crucial for cancer progression, as well as for driving the inflammatory response in the tumor microenvironment. The increasingly common use of HA-conjugated drugs in oncology, as well as HA-based compounds as adjuvants in cancer treatment, adds further complexity to the understanding of the net effect of hyaluronan-CD44 activation in cancers. In this review, I focus on the significance of CD44 in malignancy and discuss the dichotomous function of the hyaluronan/CD44 axis in cancer progression.

CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells

The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1^low cells present a migratory and invasive phenotype, while EWSR1::FLI1^high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1^low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.

CD44 Contributes to the Regulation of MDR1 Protein and Doxorubicin Chemoresistance in Osteosarcoma

Osteosarcoma is the most common type of pediatric bone tumor. Despite great advances in chemotherapy during the past decades, the survival rates of osteosarcoma patients remain unsatisfactory. Drug resistance is one of the main reasons, leading to treatment failure and poor prognosis. Previous reports correlated expression of cluster of differentiation 44 (CD44) with drug resistance and poor survival of osteosarcoma patients, however the underlying mechanisms are poorly defined. Here, we investigated the role of CD44 in the regulation of drug chemoresistance, using osteosarcoma cells isolated from mice carrying a mutation of the tumor suppressor neurofibromatosis type 2 (Nf2) gene. CD44 expression was knocked-down in the cells using CRISPR/Cas9 approach. Subsequently, CD44 isoforms and mutants were re-introduced to investigate CD44-dependent processes. Sensitivity to doxorubicin was analyzed in the osteosarcoma cells with modified CD44 expression by immunoblot, colony formation- and WST-1 assay. To dissect the molecular alterations induced by deletion of Cd44, RNA sequencing was performed on Cd44-positive and Cd44-negative primary osteosarcoma tissues isolated from Nf2-mutant mice. Subsequently, expression of candidate genes was evaluated by quantitative reverse transcription PCR (qRT-PCR). Our results indicate that CD44 increases the resistance of osteosarcoma cells to doxorubicin by up-regulating the levels of multidrug resistance (MDR) 1 protein expression, and suggest the role of proteolytically released CD44 intracellular domain, and hyaluronan interactions in this process. Moreover, high throughput sequencing analysis identified differential regulation of several apoptosis-related genes in Cd44-positive and -negative primary osteosarcomas, including p53 apoptosis effector related to PMP-22 (Perp). Deletion of Cd44 in osteosarcoma cells led to doxorubicin-dependent p53 activation and a profound increase in Perp mRNA expression. Overall, our results suggest that CD44 might be an important regulator of drug resistance and suggest that targeting CD44 can sensitize osteosarcoma to standard chemotherapy.

Immunotherapy in Sarcoma: Where Do Things Stand?

Early experiences with modern immunotherapy have been disappointing in trials of unselected sarcoma subtypes. However, remarkable efficacy has been observed with immune checkpoint inhibitors (ICIs) in a subset of patients, with the most promising outcomes to date in alveolar soft part sarcoma, cutaneous angiosarcoma, undifferentiated pleomorphic sarcoma (UPS), and dedifferentiated liposarcoma (dLPS). Adoptive cellular therapies targeting cancer testis antigens have shown promising activity, but only synovial sarcoma (SS) and myxoid/round cell liposarcomas reliably express these targets. The majority of sarcomas are immunologically "cold" with sparse immune infiltration, which may explain the poor response to immunotherapy. Current immunotherapy trials for sarcomas explore combination therapies with checkpoint inhibitors to overcome immune evasion and novel targets in adoptive cellular therapies. The role of tertiary lymphoid structures, PD-L1 expression, tumor mutational burden, microsatellite instability, and tumor lymphocytes as biomarkers for response are areas of active investigation. In this review, we highlight prior and ongoing clinical efforts to improve outcomes with immunotherapy and discuss the current state of understanding for biomarkers to select patients most likely to benefit from this approach.

CD44 In Sarcomas: A Comprehensive Review and Future Perspectives

It is widely accepted that the tumor microenvironment, particularly the extracellular matrix, plays an essential role in the development of tumors through the interaction with specific protein-membrane receptors. One of the most relevant proteins in this context is the transmembrane protein CD44. The role of CD44 in tumor progression, invasion, and metastasis has been well established in many cancers, although a comprehensive review concerning its role in sarcomas has not been published. CD44 is overexpressed in most sarcomas and several in vitro and in vivo experiments have shown a direct effect on tumor progression, dissemination, and drug resistance. Moreover, CD44 has been revealed as a useful marker for prognostic and diagnostic (CD44v6 isoform) in osteosarcoma. Besides, some innovative treatments such as HA-functionalized liposomes therapy have become an excellent CD44-mediated intracellular delivery system for osteosarcoma. Unfortunately, the reduced number of studies deciphering the prognostic/diagnostic value of CD44 in other sarcoma subgroups, neither than osteosarcoma, in addition to the low number of patients involved in those studies, have produced inconclusive results. In this review, we have gone through the information available on the role of CD44 in the development, maintenance, and progression of sarcomas, analyzing their implications at the prognostic, therapeutic, and mechanistic levels. Moreover, we illustrate how research involving the specific role of CD44 in the different sarcoma subgroups could suppose a chance to advance towards a more innovative perspective for novel therapies and future clinical trials.

Tumor-Infiltrating Lymphocytes and Cancer Markers in Osteosarcoma: Influence on Patient Survival

Simple Summary

Osteosarcoma (OST) is the most common type of high-grade primary bone tumor, which mainly affects young adults. Despite the efforts that have been made to address the importance of immune-related factors in OST, there is still a lot to understand. The purpose of the current study was to evaluate the tumor-infiltrating lymphocytes (TIL), the expression of proteins involved in tumor biology, and their impact on the clinical outcome of OST patients. Our results suggest that the presence of tumor-infiltrating CD4+ cells provides protection to patients, and that CD8+ cells have a significant impact on the patient’s overall survival (OS) and progression-free survival (PFS). In addition, a strong association of tumor-infiltrating CD4+ cells and the presence of CD44s expression in tumor samples was observed. These findings reinforce the idea that TIL and the expression of tumor markers should be taken into consideration in order to improve OST treatment and management.

Abstract

Osteosarcoma (OST) is the most common type of high-grade primary bone tumor, which mainly affects young adults. The current standard of care for OST combines surgical resection with chemotherapy. The clinical outcomes and the current options to treat OST patients are unsatisfactory and novel treatment strategies are needed. The crosstalk between tumor cells and immune cells is essential to the OST microenvironment. Despite the efforts that have been made to address the importance of immune-related factors in OST, there is still a lot to understand. The purpose of the current study was to evaluate the tumor-infiltrating lymphocytes (TIL), the expression of proteins involved in tumor biology, and their impact on the clinical outcome of OST patients. We studied 93 samples of OST patients using immunohistochemistry and histomorphometry. We looked for the infiltration of CD3+, CD4+, CD8+, TIA1+ and CD20+ cells and for the expression of CD44 standard (CD44s) and variant 6 (CD44v6), CD95/Fas, Fas-L, p53 and p-glycoprotein. All the parameters were analyzed for the influence on the occurrence of death and metastasis, plus patient overall survival (OS) and progression-free survival (PFS). The effect of sex, age, tumor location (distal femur or proximal tibia) and the combination with neoadjuvant chemotherapy was also assessed. Our results suggest that the presence of tumor-infiltrating CD4+ cells provides protection to OST patients, and that CD8+ cells have a significant impact on the patient’s overall survival (OS) and progression-free survival (PFS), which is more evident in male patients. In addition, a strong association between tumor-infiltrating CD4+ cells and the presence of CD44s expression in tumor samples was observed. Analysis of TIL and tumor markers related to tumor biology could be useful to stratify patients and monitor the response to therapy, as well as to assist with the development of immunotherapy strategies to improve the effects of cytotoxic TIL to eradicate the tumor cells.

Expression of CD44 and the survival in glioma: a meta-analysis

Background: Higher tumor expression of CD44, a marker of cancer stem cells (CSCs), is associated with poor overall survival (OS) in various cancers. However, the association between CD44 and poor OS remains inconsistent in glioma. We aimed to evaluate the potential predictive role of CD44 for prognosis of glioma patients in a meta-analysis.

Methods: Observational studies comparing OS of glioma patients according to the level of CD44 were identified through searching PubMed, Embase, and Cochrane’s Library databases. Meta-analyses were performed with a random- or fixed-effect model according to the heterogeneity. Subgroup analyses were performed to evaluate the influences of study characteristics.

Results: Eleven retrospective cohort studies were included. Results showed that increased CD44 expression in tumor predicted poor OS in glioma patients (hazard ratio [HR]: 1.42, 95% confidence interval [CI]: 1.02–1.97, P=0.04). Subgroup analyses showed that higher tumor CD44 expression significantly predicted poor OS in patients with World Health Organization (WHO) stages II–III glioma (HR: 2.99, 95% CI: 1.53–5.89, P=0.002), but not in patients with glioblastoma (HR: 1.26, 95% CI: 0.76–2.08, P=0.47; P for subgroup difference = 0.03). Results were not statistically different between subgroups according to patient ethnicity, sample size, CD44 detection method, CD44 cutoff, HR estimation, univariate or multivariate analysis, or median follow-up durations (P-values for subgroup difference all >0.10).

Conclusion: Higher tumor expression of CD44 may predict poor survival in patients with glioma, particularly in those with WHO stage II–III glioma.

Cluster of differentiation 44 promotes osteosarcoma progression in mice lacking the tumor suppressor Merlin

Merlin is a versatile tumor suppressor protein encoded by the NF2 gene. Several lines of evidence suggest that Merlin exerts its tumor suppressor activity, at least in part, by forming an inhibitory complex with cluster of differentiation 44 (CD44). Consistently, numerous NF2 mutations in cancer patients are predicted to perturb the interaction of Merlin with CD44. We hypothesized that disruption of the Merlin-CD44 complex through loss of Merlin, unleashes putative tumor- or metastasis-promoting functions of CD44. To evaluate the relevance of the Merlin-CD44 interaction in vivo, we compared tumor growth and progression in Cd44-positive and Cd44-negative Nf2-mutant mice. Heterozygous Nf2-mutant mice were prone to developing highly metastatic osteosarcomas. Importantly, while the absence of the Cd44 gene had no effect on the frequency of primary osteosarcoma development, it strongly diminished osteosarcoma metastasis formation in the Nf2-mutant mice. In vitro assays identified transendothelial migration as the most prominent cellular phenotype dependent on CD44. Adhesion to endothelial cells was blocked by interfering with integrin α4β1 (very late antigen-4, VLA-4) on osteosarcoma cells and CD44 upregulated levels of integrin VLA-4 β1 subunit. Among other putative functions of CD44, which may contribute to the metastatic behavior, the passage through the endothelial cells also appears to be critical in vivo, as CD44 significantly promoted formation of lung metastasis upon intravenous injection of osteosarcoma cells into immunocompromised mice. Altogether, our results strongly suggest that CD44 plays a metastasis-promoting role in the absence of Merlin.

Prognostic Impact of CD44 Expression in Patients With Myxofibrosarcoma

BACKGROUND/AIM

Abnormal expression of CD44 may promote cancer invasion. However, a limited number of studies have investigated the expression of CD44 in soft tissue sarcoma such as myxofibrosarcoma. We evaluated the relationship between expression of the standard form of CD44 (CD44s) and the clinical course of myxofibrosarcoma.

MATERIALS AND METHODS

Forty-four myxofibrosarcoma patients were retrospectively enrolled. Patient information including the proportion of CD44s-positive cells was collected, and multivariate analyses were conducted to determine the relationship between CD44s expression and clinicopathological factors.

RESULTS

Although CD44s did not affect prognosis, multivariate analysis indicated that high expression of CD44s predicted poor event-free survival (p=0.004) and local recurrence (p=0.049). CD44s expression was not associated with the occurrence of distant metastasis but was significantly higher in those with lung metastasis (p=0.044).

CONCLUSION

Increased expression of CD44s predicted poor event-free survival and local recurrence and was observed in myxofibrosarcoma patients with lung metastasis.

Surface engineering of nanoparticles with ligands for targeted delivery to osteosarcoma

Osteosarcoma is one of the most common malignant bone tumors which affect adolescents. Neoadjuvant chemotherapy followed by operation has become recommended for osteosarcoma treatment. Whereas, the effects of conventional chemotherapy are unsatisfactory because of multidrug resistance, fast clearance rate, nontargeted delivery, side effects and so on. Accordingly, Nanoparticle-mediated targeted drug delivery system (NTDDS) is recommended to be a novel treatment strategy for osteosarcoma. NTDDS can overcome the above obstacles by enhanced permeability and retention effect and active targeting. The active targeting of the delivery system is mainly based on ligands. In this study, we investigate and summarize the most common ligands used in the latest NTDDS for osteosarcoma. It might provide new insights into nanomedicine for osteosarcoma treatment.

The cancer-related transcription factor RUNX2 modulates expression and secretion of the matricellular protein osteopontin in osteosarcoma cells to promote adhesion to endothelial pulmonary cells and lung metastasis

Osteosarcomas are bone tumors that frequently metastasize to the lung. Aberrant expression of the transcription factor, runt-related transcription factor 2 (RUNX2), is a key pathological feature in osteosarcoma and associated with loss of p53 and miR-34 expression. Elevated RUNX2 may transcriptionally activate genes mediating tumor progression and metastasis, including the RUNX2 target gene osteopontin (OPN/SPP1). This gene encodes a secreted matricellular protein produced by osteoblasts to regulate bone matrix remodeling and tissue calcification. Here we investigated whether and how the RUNX2/OPN axis regulates lung metastasis of osteosarcoma. Importantly, RUNX2 depletion attenuates lung metastasis of osteosarcoma cells in vivo. Using next-generation RNA-sequencing, protein-based assays, as well as the loss- and gain-of-function approaches in selected osteosarcoma cell lines, we show that osteopontin messenger RNA levels closely correlate with RUNX2 expression and that RUNX2 controls the levels of secreted osteopontin. Elevated osteopontin levels promote heterotypic cell-cell adhesion of osteosarcoma cells to human pulmonary microvascular endothelial cells, but not in the presence of neutralizing antibodies. Collectively, these findings indicate that the RUNX2/OPN axis regulates the ability of osteosarcoma cells to attach to pulmonary endothelial cells as a key step in metastasis of osteosarcoma cells to the lung.

Is malnutrition associated with postoperative complications in patients with primary bone sarcomas?

BACKGROUND

Modifiable risk factors that can be optimized to minimize postoperative complications in patients with bone sarcomas are yet to be identified.

METHODS

We retrospectively identified 275 patients aged 18 and older who underwent surgery for primary bone sarcomas who also had albumin values recorded within 4 weeks before surgery. Postoperative complications were defined as infection, hematoma, need for additional surgery, or wound complications.

RESULTS

In the multivariate analysis, age (P = 0.049) and neoadjuvant radiotherapy (P = 0.008) were independently associated with postoperative complications. We then performed a subanalysis of patients without a pelvic tumor who also did not receive radiotherapy (n = 178). In this population, albumin less than 2.8 g/dL was found to be independently associated with postoperative complications (odds ratio [OR], 4.69. 95% confidence intervals [CI], 1.03-21.97; P = 0.046).

CONCLUSIONS

This study demonstrates that hypoalbuminemia (albumin < 2.8 g/dL) is associated with postoperative complications in patients with nonpelvic bone sarcomas who do not receive radiation. Future studies are necessary to further elucidate the role of nutrition, and they may show that nutritional status is a modifiable risk factor that can be optimized to improve the outcome of surgery for primary bone sarcomas.

Prognostic significance of matrix metalloproteinase 9 expression in osteosarcoma: A meta-analysis of 16 studies

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) is significant in the progression of osteosarcoma (OS) via increasing tumor growth, invasion and metastasis. Although previous reports indicate the prognostic value of MMP-9 in OS, there is still a great degree on inconsistency between studies. Here we report a comprehensive evaluation of the value of MMP-9 in metastasis of OS by conducting a meta-analysis of published studies.

METHODS

The quantity of the studies was evaluated using the Newcastle-Ottawa quality assessment scale (NOS). Sixteen studies with a total of 816 patients with OS were examined and we calculated the pooled odds ratio (OR) with corresponding 95% confidence interval (CI) (95% CI) to evaluate that the positive expression of MMP-9 predicts neoplasm metastasis and poor survival in OS.

RESULTS

The results of Meta-analysis indicated that patients with positive expression of MMP-9 were significantly associated with neoplasm metastasis (OR = 4.69, 95% CI: 3.05-7.21, P <.001) and poor survival in OS with the pooled OR of 7.19 (95% CI 4.32-11.98, P <.001) when compared to their counterparts with a negative expression of MMP-9. The results of sensitivity analysis showed that the pooled OR was stable. It doesn't significantly change when a single study was removed.

CONCLUSIONS

The results of meta-analysis indicated that MMP-9 may be a prognostic biomarker guiding the clinical therapy for OS.

Anoikis‑resistant human osteosarcoma cells display significant angiogenesis by activating the Src kinase‑mediated MAPK pathway

Tumor cells must resist anoikis to metastasize. There is a key role of angiogenesis in the growth and metastasis of tumors. However, the relationship between anoikis resistance and angiogenesis has not been well explored in human osteosarcoma. In the present study, we reported the higher expression of vascular endothelial growth factor-A (VEGF-A) in osteosarcoma cells that were resistant to anoikis than in parental osteosarcoma cells, promoting the proliferation, tube formation, and migration of human umbilical vein endothelial cells (HUVECs). Src, JNK (Jun amino-terminal kinase) and ERK (extracellular signal-regulated kinase) signaling pathway phosphorylation was activated in anoikis-resistant cells; Src inhibitor reduced the expression of VEGF-A and angiogenesis and inhibited JNK and ERK pathway activity. Overexpression of phosphorylated (p)-Src and VEGF-A was positively correlated to the metastatic potential in human osteosarcoma tissues, as quantified by immunohistochemistry. In addition, p-Src expression was directly correlated with VEGF-A expression and microvessel density in vivo. Our findings revealed that anoikis resistance in osteosarcoma cells increased the expression of VEGF-A and angiogenesis through the Src/JNK/ERK signaling pathways. Thus, Src may be a potential therapeutic alternative in osteosarcoma angiogenesis and metastasis.

Prognostic value of CD44v6 expression in breast cancer: a meta-analysis

Purpose

The prognostic value and clinical significance of CD44 variant isoform v6 (CD44v6) in breast cancer remains controversial. Our study aimed to generalize the correlation between CD44v6 expression and clinicopathological features and prognosis in breast cancer by using a meta-analysis.

Methods

We performed a comprehensive search of relevant literature from PubMed, Cochrane Database, and EMBASE database that were published before January 2018. The pooled ORs and HRs with 95% CIs were used to estimate the effects.

Results

Thirteen articles comprising 1,458 patients were included for analysis. The results revealed that CD44v6 expression was associated with histological grade (overall: OR=1.56, 95% CI [1.06, 2.29], P=0.023; Asian: OR=1.78, 95% CI [1.12, 2.85], P=0.016) and lymph node metastasis (overall: OR=1.96, 95% CI [1.01, 3.78], P=0.046; Asian: OR=2.11, 95% CI [1.00, 4.44], P=0.049). CD44v6 expression was significantly associated with poor prognosis in patients with breast cancer (overall survival: overall: HR=1.55, 95% CI [1.09, 2.22], P=0.015; Asian: HR=2.22, 95% CI [1.34, 3.68], P=0.002).

Conclusion

Our meta-analysis demonstrates that CD44v6 is significantly associated with poor prognosis, histological grade, and lymph node metastasis in breast cancer patients, especially among Asian patients.

AZIN1 RNA editing confers cancer stemness and enhances oncogenic potential in colorectal cancer

Adenosine-to-inosine (A-to-I) RNA editing, a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family, is a recently discovered epigenetic modification dysregulated in human cancers. However, the clinical significance and the functional role of RNA editing in colorectal cancer (CRC) remain unclear. We have systematically and comprehensively investigated the significance of the expression status of ADAR1 and of the RNA editing levels of antizyme inhibitor 1 (AZIN1), one of the most frequently edited genes in cancers, in 392 colorectal tissues from multiple independent CRC patient cohorts. Both ADAR1 expression and AZIN1 RNA editing levels were significantly elevated in CRC tissues when compared with corresponding normal mucosa. High levels of AZIN1 RNA editing emerged as a prognostic factor for overall survival and disease-free survival and were an independent risk factor for lymph node and distant metastasis. Furthermore, elevated AZIN1 editing identified high-risk stage II CRC patients. Mechanistically, edited AZIN1 enhances stemness and appears to drive the metastatic processes. We have demonstrated that edited AZIN1 functions as an oncogene and a potential therapeutic target in CRC. Moreover, AZIN1 RNA editing status could be used as a clinically relevant prognostic indicator in CRC patients.

Prognostic role of lncRNA TUG1 for cancer outcome: Evidence from 840 cancer patients

LncRNA TUG1 has been demonstrated to be aberrantly expressed in several types of cancer and maybe serve as a prognostic marker for cancer patients. However, most individual studies have been limited by small sample sizes and controversial results. Therefore, this meta analysis was conducted to analyze available data to delineate the potential clinical application of lncRNA TUG1 on cancer prognosis, lymph node metastasis and tumor progression. Up to February 20, 2017, literature collections were conducted by comprehensive searching electronic databases, including Cochrane Library, PubMed, Embase, BioMed Central, Springer, ScienceDirect, ISI Web of Knowledge, together with three Chinese databases. The hazard ratios (HR) with 95% confidence interval (95% CI) were calculated to assess the strength of the association. Eight studies with a total of 840 cancer patients were included in the present meta analysis. The results indicated that elevated lncRNA TUG1 significantly predicted unfavorable overall survival (OS) (HR = 2.06, 95% CI: 1.23–3.45, P = 0.006), but failed to show incline to lymph node metastasis (HR: 1.16, 95% CI: 0.82–1.62, P = 0.40) and disease progression (III/IV vs. I/II: HR 1.16, 95% CI: 0.74–1.81, P = 0.52). In stratified analyses, a significantly unfavorable OS associated with elevated lncRNA TUG1 was observed in both bladder cancer (HR = 2.98, 95% CI: 1.84–4.83, P < 0.0001) and other system cancer (HR = 2.63, 95% CI: 1.42–4.87, P = 0.002), but not respiratory system cancer (HR = 0.93, 95% CI: 0.30–2.82, P = 0.895). The results indicated that increased lncRNA TUG1 was an independent prognostic biomarker for unfavorable OS but may not susceptible to lymph node metastasis and tumor progression in cancer patients.

Meta-analysis of serum lactate dehydrogenase and prognosis for osteosarcoma

BACKGROUNDS

A large number of studies have reported the relationships between serum lactate dehydrogenase (LDH) and prognosis of osteosarcoma. However, the result is still controversial and no consensus has been reached. Therefore, we performed a meta-analysis to evaluate the prognostic role of serum LDH in osteosarcoma patients.

METHODS

We performed the systematic computerized search for eligible articles from PubMed, Embase, and Cochrane databases until December 21, 2017. The pooled hazard ratio (HR) and 95% confidence intervals (CIs) of overall survival (OS) and event-free survival (EFS) were obtained to assess the prognostic value of serum LDH.

RESULTS

A total of 18 studies with 2543 osteosarcoma patients were included. Overall, 15 studies assessed the elevated serum LDH level on OS and the pooled HR was 1.87 (95% CI = 1.58-2.20). Meanwhile, the pooled HR to evaluate the relationship between serum LDH and EFS in 9 studies was 1.78 (95% CI = 1.51-2.10). The same results were acquired when these studies were stratified by Enneking stage, geographic region, and sample size. No heterogeneity existed between these subgroups (P > .05). Begg's funnel plot and Egger's test (OS: P = .04; EFS: P = .34) showed that possible publication bias might exist in OS studies. Sensitivity analysis suggested the pooled HR was robust.

CONCLUSIONS

This meta-analysis demonstrates that elevated serum LDH level is apparently associated with lower EFS rate and serum LDH could be a prognostic biomarker for osteosarcoma patients.

CD44v6 as innovative sarcoma target for CAR-redirected CIK cells

Purpose of our study was to explore a new immunotherapy for high grade soft tissue sarcomas (STS) based on cytokine-induced killer cells (CIK) redirected with a chimeric antigen receptor (CAR) against the tumor-promoting antigen CD44v6. We aimed at generating bipotential killers, combining the CAR specificity with the intrinsic tumor-killing ability of CIK cells (CAR⁺.CIK). We set a patient-derived experimental platform. CAR⁺.CIK were generated by transduction of CIK precursors with a lentiviral vector encoding for anti-CD44v6-CAR. CAR⁺.CIK were characterized and assessed in vitro against multiple histotypes of patient-derived STS. The anti-sarcoma activity of CAR⁺.CIK was confirmed in a STS xenograft model. CD44v6 was expressed by 40% (11/27) of patient-derived STS. CAR⁺.CIK were efficiently expanded from patients (n = 12) and killed multiple histotypes of STS (including autologous targets, n = 4). The killing activity was significantly higher compared with unmodified CIK, especially at low effector/target (E/T) ratios: 98% vs 82% (E/T = 10:1) and 68% vs 26% (1:4), (p<0.0001). Specificity of tumor killing was confirmed by blocking with anti-CD44v6 antibody. CAR⁺.CIK produced higher amounts of IL6 and IFN-γ compared to control CIK. CAR⁺.CIK were highly active in mice bearing subcutaneous STS xenografts, with significant delay of tumor growth (p<0.0001) without toxicities.

We report first evidence of CAR⁺.CIK's activity against high grade STS and propose CD44v6 as an innovative target in this setting. CIK are a valuable platform for the translation of CAR-based strategies to challenging field of solid tumors. Our findings support the exploration of CAR⁺.CIK in clinical trials against high grade STS.

CD44v6 overexpression related to metastasis and poor prognosis of colorectal cancer: A meta-analysis

CD44v6 has recently been reported as a biomarker for colorectal cancer. However, the clinical and prognostic significance of CD44v6 in colorectal cancer remains controversial. Therefore, we performed a meta-analysis to clarify this issue. A comprehensive literature search was performed using Medline, Embase and Web of Science, and the statistical analysis was conducted using Stata software. A total of twenty-one studies including 3918 colorectal cancer cases were included. The pooled analysis showed that CD44v6 overexpression in colorectal cancer was an independent prognostic marker correlating with lower 5-year overall survival rate (OR=0.78, 95%CI =0.67-0.91, p=0.001). CD44v6 overexpression was also associated with more lymph node invasion (OR=1.48, 95%CI= 1.02-2.15, p=0.04), and advanced Dukes stage (OR=2.47, 95%CI= 1.29-4.73, p=0.01). In addition, while excluding Zolbec's study, CD44v6 overexpression was associated with distance metastasis (OR=1.65, 95%CI =1.13-2.40, p=0.01). Taken together, this meta-analysis suggested that CD44v6 is an efficient prognostic factor in colorectal cancer.

MLLT3 promotes proliferation of osteosarcoma cells by regulating JNK signaling

Osteosarcoma was the most common malignant tumor derived from bone/soft tissues and afflicted mainly the adolescents. Surgical removing assisted with chemotherapy/radiotherapy was the major therapeutics regardless of high mortality. MLLT3 was one of the most common partners fused with mixed lineage leukemia gene and caused leukemia. But its role in osteosarcoma was not previously reported. In this study, we found that MLLT3 was expressed abundantly in osteosarcoma tissues and cell lines including U-2OS, MG-63, Saos-2 and HOS. And by Kaplan-Meier analysis, MLLT3 expression was shown to be clinically correlated with survival of osteosarcoma patients. The 5-year survival rate was 64.3% for patients with low MLLT3 expression (n=14) while it was 36.4% for patients with high MLLT3 expression (n=11). The difference was significant (p=0.026). When MLLT3 was knocked-down, the proliferation ability decreased about 38% in HOS cells and 46% in MG-63 cells. But the migration as well as the invasive ability was not affected. In addition, the expression level of β-catenin was comparable in HOS cells with/without knockdown of MLLT3. The specific inhibitor LGK-974 against Wnt/β-catenin signaling showed little additive effect with MLLT3 knockdown on growth ability of HOS cells. But the level of c-Jun, BCL-2, Akt and c-Myc was significantly decreased in HOS cells with MLLT3 knockdown, which indicated that MLLT3 may at least partially regulate JNK signaling in HOS cells. In conclusion, we proved MLLT3 as an oncogene in osteosarcoma through partially regulating the JNK signaling pathway. And MLLT3 may be a promising target for treatment of patients with osteosarcoma.

Prognostic value of lncRNA SOX2OT for Chinese cancer patients: A meta-analysis

SOX2OT has been demonstrated to be aberrantly expressed in several types of cancer and maybe serve as a prognostic marker for cancer patients. However, most individual studies have been limited by small sample sizes and controversial results. Therefore, the present meta-analysis was conducted to analyze available data to reveal the potential clinical application of SOX2OT on cancer prognosis, tumor progression, distance metastasis and lymph node metastasis. Up to February 20, 2017, literature collections were conducted by comprehensive searching electronic databases, including Cochrane Library, PubMed, Embase, BioMed Central, Springer, ScienceDirect, ISI Web of Knowledge, together with three Chinese databases: China National Knowledge Internet (CNKI), Weipu and Wanfang. The hazard ratios (HR) with 95% confidence interval (95% CI) were calculated to assess the strength of the association. Five studies with a total of 481 cancer patients were included in the present meta-analysis. The results indicated that elevated SOX2OT significantly predicted unfavorable overall survival (OS) (HR = 2.44, 95% CI: 1.75–3.39, P<0.0001) and tumor progression (III/IV vs. I/II: HR 1.62, 95%CI: 1.30–2.02, P<0.0001), but failed to predict distant metastasis (HR: 3.30, 95%CI: 0.74–14.61, P = 0.12) and lymph node metastasis (HR: 1.29, 95% CI: 0.87–1.91, P = 0.21). The results revealed that SOX2OT expression level was an independent prognostic biomarker for OS and tumor progression in Chinese cancer patients.

Diagnostic accuracy of CD44V6 for osteosarcoma: a meta-analysis

Background

Recently, more and more evidences have revealed the association between CD44V6 and osteosarcoma (OS), but whether it can be used as a clinical biomarker is still unknown. The purpose of this study is to assess the diagnostic value of CD44V6 in OS by conducting a meta-analysis.

Methods

All relevant electronic literatures were collected from seven international databases together with three Chinese databases up to April 23, 2016. Eligible studies were selected through multiple search strategies and the quality was assessed by QUADAS. Data was extracted from studies according to the key statistics index. All analyses were performed using STATA 12 and Meta-DiSc 1.4 statistical software.

Results

According to the exclusion and inclusion criteria, 8 literatures were retrieved, accounting for 463 cases and 188 controls. For discriminating OS from benign bone tumor or healthy controls, the area under the receiver operating characteristic curve (AUC) was 0.91 (95 % CI 0.88–0.93). Overall, the results showed pooled sensitivity of 0.743 (95 % CI 0.606–0.844) and specificity of 0.897 (95 % CI 0.818–0.945), respectively. Substantial heterogeneity was detected in this study (I² = 90 %). The publication bias was assessed by using Deeks’ asymmetry test (p = 0.795). No evidence of heterogeneity from threshold effects was detected by the Spearman correlation coefficient (−0.506, p = 0.201). Meta-regression was performed to mining the source of heterogeneity, and subgroup analysis showed that neither the cut-off values nor the control groups were the source of heterogeneity.

Conclusions

The present results suggest that promoted CD44V6 expression levels are associated with OS and CD44V6 may be used as a diagnostic marker for OS.