PIK3CA and AKT gene polymorphisms in susceptibility to osteosarcoma in a Chinese population

The role of programmed cell death in osteosarcoma: From pathogenesis to therapy

Osteosarcoma (OS) is a prevalent bone solid malignancy that primarily affects adolescents, particularly boys aged 14-19. This aggressive form of cancer often leads to deadly lung cancer due to its high migration ability. Experimental evidence suggests that programmed cell death (PCD) plays a crucial role in the development of osteosarcoma. Various forms of PCD, including apoptosis, ferroptosis, autophagy, necroptosis, and pyroptosis, contribute significantly to the progression of osteosarcoma. Additionally, different signaling pathways such as STAT3/c-Myc signal pathway, JNK signl pathway, PI3k/AKT/mTOR signal pathway, WNT/β-catenin signal pathway, and RhoA signal pathway can influence the development of osteosarcoma by regulating PCD in osteosarcoma cell. Therefore, targeting PCD and the associated signaling pathways could offer a promising therapeutic approach for treating osteosarcoma.

Exploration in the Mechanism of Ginsenoside Rg5 for the Treatment of Osteosarcoma by Network Pharmacology and Molecular Docking

OBJECTIVE

Osteosarcoma is a primary malignancy originating from mesenchymal tissue characterized by rapid growth, early metastasis and poor prognosis. Ginsenoside Rg5 (G-Rg5) is a minor ginsenoside extracted from Panax ginseng C.A. Meyer which has been discovered to possess anti-tumor properties. The objective of current study was to explore the mechanism of G-Rg5 in the treatment of osteosarcoma by network pharmacology and molecular docking technology.

METHODS

Pharmmapper, SwissTargetPrediction and similarity ensemble approach databases were used to obtain the pharmacological targets of G-Rg5. Related genes of osteosarcoma were searched for in the GeneCards, OMIM and DrugBank databases. The targets of G-Rg5 and the related genes of osteosarcoma were intersected to obtain the potential target genes of G-Rg5 in the treatment of osteosarccoma. The STRING database and Cytoscape 3.8.2 software were used to construct the protein-protein interaction (PPI) network, and the Database for Annotation, Visualization and Integrated Discovery (DAVID) platform was used to perform gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. AutoDock vina software was used to perform molecular docking between G-Rg5 and hub targets. The hub genes were imported into the Kaplan-Meier Plotter online database for survival analysis.

RESULTS

A total of 61 overlapping targets were obtained. The related signaling pathways mainly included PI3K-Akt signaling pathway, Proteoglycans in cancer, Lipid and atherosclerosis and Kaposi sarcoma-associated herpesvirus infection. Six hub targets including PIK3CA, SRC, TP53, MAPK1, EGFR, and VEGFA were obtained through PPI network and targets-pathways network analyses. The results of molecular docking showed that the binding energies were all less than -7 kcal/mol. And the results of survival analysis showed TP53 and VEGFA affect the prognosis of sarcoma patients.

CONCLUSION

This study explored the possible mechanism of G-Rg5 in the treatment of osteosarcoma using network pharmacology method, suggesting that G-Rg5 has the characteristics of multi-targets and multi-pathways in the treatment of osteosarcoma, which lays a foundation for the follow-up experimental and clinical researches on the therapeutic effects of G-Rg5 on osteosarcoma.

Non-coding RNAs as potential biomarkers in osteosarcoma

Osteosarcoma (OS) is a primary solid malignant tumor that occurs most frequently in the metaphysis of long bones. More likely to happen to children and adolescents. OS has high mortality and disability rate. However, the etiology and pathogenesis of OS have not been fully understood till now. Due to the lack of effective biomarkers, OS cannot be precisely detected in the early stage. With the application of next-generation and high-throughput sequencing, more and more abnormally expressed non-coding RNAs(ncRNAs) have been identified in OS. Growing evidences have suggested the ncRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), have played an important role in the tumorigenesis and progression of OS. Thus, they can be served as novel biomarkers for diagnosis, treatment and prognosis. This review summarized the application of ncRNA as biomarkers in OS in detail, and discussed the limitation and future improvement of the potential biomarkers.

DNA damage response and repair in osteosarcoma: Defects, regulation and therapeutic implications

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents which has the survival rate of 20% in its advanced stages. Osteosarcomas are mostly resistance to our common treatments. DNA damage response (DDR) is a specialized multistep process containing abundant proteins which are necessary for the survival of any cell and organism. DDR machinery detects a diversity of DNA lesions and inhibits the cell cycle progression if these lesions are not repairable. DDR is involved in aging, age-related diseases, and cancer. In recent years, DDR inhibitors have gained the attention of researches due to their potentials in offering novel therapeutic targets and improving the response of many cancers to either chemo- or radio-therapy. In this regard, we tried to gather a great body of evidence about the role of DDR ingredients in osteosarcoma's initiation/progression, prognosis, and treatment.

An update on the roles of circular RNAs in osteosarcoma

Osteosarcoma is the most common primary bone malignancy and is a neoplasm thought to be derived from the bone‐forming mesenchymal stem cells. Aberrant activation of oncogenes and inactivation of tumour suppressor genes by somatic mutations and epigenetic mechanisms play a pivotal pathogenic role in osteosarcoma. Aside from alterations in these protein‐coding genes, it has now been realized that dysregulation of non‐coding RNAs (ncRNAs), including microRNAs (miRNAs), long non‐coding RNAs (lncRNAs) and the recently discovered circular RNAs (circRNAs), is crucial to the initiation and progression of osteosarcoma. CircRNAs are single‐stranded RNAs that form covalently closed loops and function as an important regulatory element of the genome through multiple machineries. Recently, an increasing number of studies suggested that circRNAs also played critical roles in osteosarcoma. This review summarizes recent development and progression in circRNA transcriptome analysis and their functions in the modulation of osteosarcoma progression.

Putative functional variants of PI3K/AKT/mTOR pathway are associated with knee osteoarthritis susceptibility

BACKGROUND

Osteoarthritis (OA) is a degenerative musculoskeletal disease which causes joint deformity and pain and finally leads to limb dysfunction. Knee osteoarthritis (KOA) has the highest incidence among all kinds of OA. Strong evidence leads to the understanding that P13K/AKT/mTOR signaling is very important in cartilage degeneration.

METHODS

This research sought to understand the association between genetic variation of PI3K/AKT/mTOR genes and KOA susceptibility among Chinese population. All the genetic variants of PI3K/AKT/mTOR pathway were graded and selected using RegulomeDB database, and then, an association study including 278 osteoarthritis patients and 289 controls was conducted.

RESULTS

Finally, eight SNPs' genotypes' distributions and susceptibility to KOA were presented. AKT1 rs2498789 was associated with KOA susceptibility in dominate genetic model (AA + GA vs GG) after adjusted for BMI, age, and gender: OR = 1.46, 95% CI: 1.03-2.05, P = .03. PIK3CA rs7646409 was also associated with KOA susceptibility (TC vs TT) after adjusted for BMI, age, and gender: OR = 0.58, 95% CI: 0.36-0.93, P = .02. PIK3CA rs7646409 (TC vs TT) with KOA risk was more significant in age < 60 group (P for heterogeneity was .03). Risk score showed significant association with KOA susceptibility after cumulative analysis (OR = 2.45, 95% CI: 1.35-4.45, P = .003).

CONCLUSIONS

This study shows that genetic variation of PI3K/AKT/mTOR is associated with KOA susceptibility in Chinese Han population, indicating that PI3K/AKT/mTOR is very important in KOA pathogenesis.

COX‑2 promotes epithelial‑mesenchymal transition and migration in osteosarcoma MG‑63 cells via PI3K/AKT/NF‑κB signaling

The present study aimed to investigate the mechanism by which cyclooxygenase-2 (COX-2) promotes the metastasis of MG-63 osteosarcoma cells through the PI3K/AKT/NF-κB pathway. To achieve this, a recombinant lentivirus containing the COX-2 gene was constructed in order to overexpress COX-2; a recombinant lentivirus containing a control sequence was also constructed. A Transwell chamber migration assay was performed to quantify the migration of the COX-2-transduced cells, and of cells treated with a COX-2 inhibitor (NS398) or a PI3K inhibitor (LY294002). Immunofluorescence assays were performed to determine changes in E-cadherin, vimentin and NF-κB expression levels. ELISAs were performed to quantify the levels of matrix metallopeptidase (MMP)-2, MMP-9 and vascular endothelial growth factor (VEGF) in the culture medium. Western blot analysis was conducted to measure the protein expression levels of MMP-2, MMP-9, PI3K, phosphorylated (p-) PI3K, AKT, p-AKT, inhibitor of NF-κΒ kinase (IKK) and p-IKK. The results demonstrated that the migration ability of the COX-2-overexpressing MG-63 cells was significantly increased compared with the control cells. The migration ability of cells treated with NS398 or LY294002 was significantly decreased. Compared with the control cells, E-cadherin expression was significantly decreased in COX-2-overexpressing cells, while the expression levels of vimentin, MMP-2, MMP-9, VEGF, p-PI3K, p-AKT and p-IKK were significantly increased. Compared with the control cells, E-cadherin expression was significantly increased in cells treated with NS398 or LY294002, while the expression levels of vimentin, MMP-2, MMP-9, VEGF, p-PI3K, p-AKT, and p-IKK were significantly decreased. The total protein levels of PI3K, AKT and IKK were not changed among the treatment groups. In summary, COX-2 overexpression decreased the expression levels of the epithelial protein E-cadherin and increased the expression levels of the mesenchymal proteins vimentin, MMP-2 and MMP-9, as well as promoted cell migration, by activating the PI3K/AKT/NF-κB signaling pathway.

Association between AKT rs2494752 single nucleotide polymorphism and the risk of metastasis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of human tumors, which is characterized by high morbidity and mortality rates. AKT1 transcriptional activity is implicated in HCC initiation and development. In the present study, the effects of rs2494752 single nucleotide polymorphism (SNP) on AKT1 transcriptional activity in the progression of HCC cells were investigated. A case-control study was analyzed in 1,056 HCC patients and 1,080 healthy individuals using the PCR assay method. Results indicated AKT1 expression levels were up-regulated in HCC tissue compared to adjacent normal tissues. Furthermore, a higher frequency of AKT rs2494752 AG and AA genotypes were observed in HCC cases (P=0.0046). Gene polymorphism identified C and T alleles were frequency in HCC patients compared to healthy individuals. Individuals harboring AKT rs2494752 AG/AA genotype had a vital increased susceptibility to HCC in the dominant model (P=0.0028). In addition, AKT1 rs2494752 GG genotype showed an increasing of AKT1 promoter activity determined by the luciferase assay. Furthermore, it was demonstrated that AKT1 rs2494752 GG and C polymorphism was more aggressive than other AKT1 rs2494752 cancer cells. Moreover, AKT1 rs2494752 GG markedly increased rates of response to NCT chemotherapy. Additionally, results revealed that AKT1 rs2494752 GG and C increased the risk factors of HCC. In conclusion, these results indicate that AKT1 rs2494752 polymorphisms may be regarded as a candidate gene in assessing the susceptibility, metastasis and responses to chemotherapy in the progression of hepatocellular carcinoma.

Genetic susceptibility to bone and soft tissue sarcomas: a field synopsis and meta-analysis

Background

The genetic architecture of bone and soft tissue sarcomas susceptibility is yet to be elucidated. We aimed to comprehensively collect and meta-analyze the current knowledge on genetic susceptibility in these rare tumors.

Methods

We conducted a systematic review and meta-analysis of the evidence on the association between DNA variation and risk of developing sarcomas through searching PubMed, The Cochrane Library, Scopus and Web of Science databases. To evaluate result credibility, summary evidence was graded according to the Venice criteria and false positive report probability (FPRP) was calculated to further validate result noteworthiness. Integrative analysis of genetic and eQTL (expression quantitative trait locus) data was coupled with network and pathway analysis to explore the hypothesis that specific cell functions are involved in sarcoma predisposition.

Results

We retrieved 90 eligible studies comprising 47,796 subjects (cases: 14,358, 30%) and investigating 1,126 polymorphisms involving 320 distinct genes. Meta-analysis identified 55 single nucleotide polymorphisms (SNPs) significantly associated with disease risk with a high (N=9), moderate (N=38) and low (N=8) level of evidence, findings being classified as noteworthy basically only when the level of evidence was high. The estimated joint population attributable risk for three independent SNPs (rs11599754 of ZNF365/EGR2, rs231775 of CTLA4, and rs454006 of PRKCG) was 37.2%. We also identified 53 SNPs significantly associated with sarcoma risk based on single studies.Pathway analysis enabled us to propose that sarcoma predisposition might be linked especially to germline variation of genes whose products are involved in the function of the DNA repair machinery.

Conclusions

We built the first knowledgebase on the evidence linking DNA variation to sarcomas susceptibility, which can be used to generate mechanistic hypotheses and inform future studies in this field of oncology.

Association between single nucleotide polymorphisms in the PI3K/AKT/mTOR pathway and bladder cancer risk in a sample of Iranian population

In the past few years several investigations have focused on the role of PI3K/AKT/mTOR pathway and its deregulations in different cancers. This study aimed to examine genetic polymorphisms of this pathway in bladder cancer (BC). In this case-control study, 235 patients with pathologically confirmed bladder cancer and 254 control subjects were examined. PIK3CA, AKT1 and mTOR variants were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The findings proposed that the PIK3CA rs6443624 SNP significantly decreased the risk of BC (OR=0.44, 95 % CI=0.30-0.65, p<0.0001 CA vs CC; OR=0.35, 95 % CI=0.16-0.78, p=0.0107, AA vs CC; OR=0.60, 95 % CI=0.46-0.79, p=0.0002, A vs T). The AKT1 rs2498801 variant is associated with a decreased risk of BC (OR=0.57, 95 % CI=0.39-0.82, p=0.003, AG vs AA; OR=0.74, 95 % CI=0.56-0.97, p=0.032, G vs A) while, AKT1 rs1130233 polymorphism considerably increased the risk of BC (OR=3.70, 95 % CI=2.52-5.43, p<0.0001, GA vs GG; OR=5.81, 95 % CI=1.53-21.97, p=0.010, AA vs GG; OR=2.71, 95 % CI=1.98-3.70, p<0.0001, A vs G). Additionally, mTOR rs2295080 variant notably increased the risk of BC (OR=2.25, 95 % CI=1.50-3.38, p<0.0001, GT vs GG; OR=4.75, 95 % CI=2.80-8.06, p<0.0001, TT vs GG; OR=3.10, 95 % CI=2.34-4.10, p<0.0001, T vs G). None of the other examined polymorphisms (AKT1 rs1130214, AKT1 rs3730358, mTOR rs1883965) revealed significant association with BC. In conclusion, our findings suggest that PIK3CA rs6443624, AKT1 rs2498801, AKT1 rs1130233, as well mTOR rs2295080 polymorphism may be related to bladder cancer development in a sample of Iranian population. Validation of our findings in larger sample sizes of different ethnicities would provide evidence on the role of variants of PI3K/AKT/mTOR pathway in developing BC.

MicroRNA-26a induces osteosarcoma cell growth and metastasis via the Wnt/β-catenin pathway

MicroRNAs (miRNAs/miRs) are a type of highly conserved, small non-coding RNA that are vital to the post-transcriptional regulation of gene expression via base pairing with target mRNA 3'-untranslated regions (3'-UTRs). Several studies have indicated that the abnormal expression of miRNAs occurs frequently in human osteosarcoma (OS). In the present study, the role of miR-26a in the progression and metastasis of OS was investigated using reverse transcription-quantitative polymerase chain reaction, a luciferase activity assay, cell viability assay, in vitro migration and invasion assays, transfection and western blot analysis. miR-26a was upregulated in OS tissues and cell lines, and the expression of miR-26a was indicated to affect the proliferation, migration and invasion of OS Saos-2 cells. At the molecular level, the results showed that glycogen synthase kinase-3β (GSK-3β) was identified as a target of miR-26a, and the ectopic expression of miR-26a inhibited GSK-3β by directly binding to the 3'-UTR. Therefore, the expression of miR-26a was negatively correlated with GSK-3β in the OS tissues. These data suggest that miR-26a is significant in the proliferation of human OS cells due to the direct regulation of Wnt/β-catenin signaling.

GRM4 gene polymorphism is associated with susceptibility and prognosis of osteosarcoma in a Chinese Han population

Osteosarcoma (OS), the most common primary bone malignancy, occurs primarily in adolescents and young adults. In earlier genome-wide association studies, rs7591996, rs10208273, rs17206779 and rs1906953 were identified as candidate loci for OS in Caucasians but the association of these single-nucleotide polymorphisms (SNPs) with OS in a Chinese Han population remains unknown. We measured the frequency of these four variants in a Chinese Han population to better understand the genetic etiology of OS. Polymerase chain reaction sequencing was used to detect the genotypes of four candidate SNPs in peripheral blood samples collected from 168 OS patients and 216 healthy controls. Logistic regression models were used to estimate the odds ratios and 95 % confidence intervals. We found rs1906953 in the glutamate receptor metabotropic 4 (GRM4) gene was associated significantly with OS in our Chinese Han population; as with the other SNPs, however, no statistically significant difference was detected. Further analysis showed the association between rs1906953 and OS was independent of gender and age. The rs1906953 locus was not associated with Enneking stages or tumor location; however, it was associated significantly with OS metastasis and prognosis. The GRM4 gene polymorphism was associated with the susceptibility and metastasis of OS in a Chinese Han population.

Detection of PIK3CA gene mutations with HRM analysis and association with IGFBP-5 expression levels in breast cancer

Breast cancer is the second most common cancer and second leading cause of cancer deaths in women. Phosphatidylinositol-3-kinase (PI3K)/AKT pathway mutations are associated with cancer and phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene mutations have been observed in 25-45% of breast cancer samples. Insulin growth factor binding protein-5 (IGFBP-5) can show different effects on apoptosis, cell motility and survival in breast cancer. We here aimed to determine the association between PIK3CA gene mutations and IGFBP-5 expressions for the first time in breast cancer patients. Frozen tumor samples from 101 Turkish breast cancer patients were analyzed with high resolution melting (HRM) for PIK3CA mutations (exon 9 and exon 20) and 37 HRM positive tumor samples were analyzed by DNA sequencing, mutations being found in 31. PIK3CA exon 9 mutations (Q546R, E542Q, E545K, E542K and E545D) were found in 10 tumor samples, exon 20 mutations (H1047L, H1047R, T1025T and G1049R) in 21, where only 1 tumor sample had two exon 20 mutations (T1025T and H1047R). Moreover, we detected one sample with both exon 9 (E542Q) and exon 20 (H1047R) mutations. 35% of the tumor samples with high IGFBP-5 mRNA expression and 29.4% of the tumor samples with low IGFBP-5 mRNA expression had PIK3CA mutations (p=0.9924). This is the first study of PIK3CA mutation screening results in Turkish breast cancer population using HRM analysis. This approach appears to be a very effective and reliable screening method for the PIK3CA exon 9 and 20 mutation detection. Further analysis with a greater number of samples is needed to clarify association between PIK3CA gene mutations and IGFBP-5 mRNA expression, and also clinical outcome in breast cancer patients.

Research progress on the livin gene and osteosarcomas

Osteosarcoma is a common malignant tumor of bone, but mechanisms underlying its development are still unclear. At present, it is believed that the inhibition of normal apoptotic mechanisms is one of the reasons for the development of tumors, so specific stimulation of tumor cell apoptosis can be considered as an important therapeutic method. Livin, as a member of the newly discovered inhibitor of apoptosis proteins (IAPs) family, has specifically high expression in tumor tissues and can inhibit tumor cell apoptosis through multiple ways, which can become a new target for malignant tumor treatment (including osteosarcoma) and might of great significance in the clinical diagnosis of tumors and the screening of anti-tumor agents and carcinoma treatment.

Role of five small nucleotide polymorphisms in the VEGF gene on the susceptibility to osteosarcoma and overall survival of patients

The present study aimed to investigate the association between five common small nucleotide polymorphisms (SNPs) in the VEGF gene and the risk of osteosarcoma. An additional aim was to investigate the role of these five SNPs on the prognosis of osteosarcoma. A total of 186 patients with osteosarcoma and 186 age- and sex-matched healthy controls were enrolled into the present study. A polymerase chain reaction-restriction fragment length polymorphism assay was conducted to determine the incidence of the VEGF-2578 C/A, -1156 G/A, +1612 G/A, +936 C/T and -634 G/C polymorphisms. Conditional logistic regression analyses revealed that individuals carrying the -634 GG genotype possessed a significantly increased risk of osteosarcoma, with an adjusted odds ratio [(95% confidence interval (CI)] of 2.00 (1.07-3.75). In the Cox proportional hazards model, subsequent to adjusting for potential confounding factors, patients with osteosarcoma carrying the -634 GG genotype were found to demonstrate a shorter overall survival time (hazard ratio, 3.10; 95% CI, 1.17-8.38). The VEGF-634 G/C polymorphism may therefore be used as a genetic marker for the prediction of the risk and clinical outcome of osteosarcoma.

Gemcitabine for the treatment of patients with osteosarcoma

BACKGROUND

Patients with recurrent or refractory osteosarcoma are considered to have a very poor prognosis, and new regimens are needed to improve the prognosis in this setting. Gemcitabine, a nucleoside antimetabolite, is an analog of deoxycytidine which mainly inhibits DNA synthesis through interfering with DNA chain elongation and depleting deoxynucleotide stores, resulting in gemcitabine-induced cell death. Here we performed a systemic analysis to evaluate gemcitabine based chemotherapy as salvage treatment for patients with recurrent or refractory osteosarcoma.

METHODS

Clinical studies evaluating the impact of gemcitabine based regimens on response and safety for patients with osteosarcoma were identified by using a predefined search strategy. Pooled response rates (RRs) of treatment were calculated.

RESULTS

In gemcitabine based regimens, 4 clinical studies which included 66 patients with recurrent or refractory osteosarcoma were considered eligible for inclusion. Systemic analysis suggested that, in all patients, pooled RR was 12.1% (8/66) in gemcitabine based regimens. Major adverse effects were hematologic toxicity, including grade 3 or 4 anemia, leucopenia and thrombocytopenia in gemcitabine based treatment. No treatment related death occurred in gemcitabine based treatment.

CONCLUSION

This systemic analysis suggests that gemcitabine based regimens are associated with mild activity with good tolerability in treating patients with recurrent or refractory osteosarcoma.

Polymorphisms in miRNA processing genes and their role in osteosarcoma risk

BACKGROUND

The possible associations between genetic variants and osteosarcoma risk have been analyzed without conclusive results. Those studies were focused mainly on genes of biologically plausible pathways. However, recently, another pathway has acquired relevance in cellular transformation and tumorigenesis, the microRNA (miRNA) processing pathway. Dysregulation of the expression levels of genes in this pathway has been described in cancer. Consequently, single nucleotide polymorphisms (SNPs) in genes that codify for proteins involved in the miRNA processing pathway may affect miRNAs, and therefore their target genes, which might be associated with cancer development and progression. The aim of this study was to evaluate whether SNPs in miRNA processing genes confer predisposition to osteosarcoma.

PROCEDURE

We analyzed 72 SNPs in 21 miRNA processing genes in a total of 99 osteosarcoma patients and 387 controls.

RESULTS

A total of three SNPs were associated with osteosarcoma susceptibility. Interestingly, these SNPs were located in miRNA processing genes (CNOT1, CNOT4 and SND1) which are part of the RISC complex. Among them, the association of rs11866002 in CNOT1 was nearly significant after Bonferroni correction.

CONCLUSIONS

This study suggests that SNPs in RISC complex genes may be involved in osteosarcoma susceptibility, especially rs11866002 in CNOT1.

A functional variant at miR-520a binding site in PIK3CA alters susceptibility to colorectal cancer in a Chinese Han population

An increasing body of evidence has indicated that polymorphisms in the miRNA binding site of target gene can alter the ability of miRNAs to bind their target genes and modulate the risk of cancer. We aimed to investigate the association between a miR-520a binding site polymorphism rs141178472 in the PIK3CA 3′-UTR and the risk of colorectal cancer (CRC) in a Chinese Han population. The polymorphism rs141178472 was analyzed in a case-control study, including 386 CRC patients and 394 age- and sex-matched controls; the relationship between the polymorphism and the risk of colorectal cancer was examined. Individuals carrying the rs141178472 CC genotype or C allele had an increased risk of developing CRC (CC versus TT, OR (95% CI): 1.716 (1.084–2.716), P = 0.022; C versus T, OR (95% CI): 1.258 (1.021–1.551), P = 0.033). Furthermore, the expression of PIK3CA was detected in the peripheral blood mononucleated cell of CRC patients, suggesting that mRNA levels of PIK3CA might be associated with SNP rs141178472. These findings provide evidence that a miR-520a binding site polymorphism rs141178472 in the PIK3CA 3′-UTR may play a role in the etiology of CRC.

PI3K/Akt signaling in osteosarcoma

Osteosarcoma (OS) is the most common nonhematologic bone malignancy in children and adolescents. Despite the advances of adjuvant chemotherapy and significant improvement of survival, the prognosis remains generally poor. As such, the search for more effective anti-OS agents is urgent. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is thought to be one of the most important oncogenic pathways in human cancer. An increasing body of evidence has shown that this pathway is frequently hyperactivated in OS and contributes to disease initiation and development, including tumorigenesis, proliferation, invasion, cell cycle progression, inhibition of apoptosis, angiogenesis, metastasis and chemoresistance. Inhibition of this pathway through small molecule compounds represents an attractive potential therapeutic approach for OS. The aim of this review is to summarize the roles of the PI3K/Akt pathway in the development and progression of OS, and to highlight the therapeutic potential of targeting this signaling pathway. Knowledge obtained from the application of these compounds will help in further understanding the pathogenesis of OS and designing subsequent treatment strategies.

Clinicopathologic features and prognosis of osteosarcoma in Turkish adults

BACKGROUND

Osteosarcomas are the most common solid malignancies of bone. In the last two decades there have been no concrete developments in their systemic treatment. In this trial we aimed to present our osteosarcoma patient clinical and demographic outcomes.

MATERIALS AND METHODS

Patients treated and followed up for osteosarcoma in Ankara Numune Education and Research Hospital from 2002 to 2012 were reviewed retrospectively.

RESULTS

A total of 21 patients (15 male, 6 female) were diagnosed with osteosarcoma. The disease was located at extremities in 76% and in 14% was metastatic at the time of diagnosis. Median disease free survival (DFS) was 36 months in non-metastatic patients and median progression free survival (PFS) was 2 months in metastatic patients (p<0.0001). Median overall survival (OS) was 80 months and 4 months, respectively (p=0.012). There were no survival differences in terms of presentation with pathological fracture, tumor size, tumor grade, alkaline phosphatase and lactate dehydrogenase level and type of chemotherapy regimen.

CONCLUSIONS

Tumor site and stages are the most important prognostic factors for osteosarcoma. Extremity primary tumors have beter survival rates than non-extremity tumors. As a result of the use of effective chemotherapy the long term survival rates have improved from 10-20% to 60-70% in the last decades but we need more active agents, especially for metastatic cases.

Ifosfamide-containing regimens for treating patients with osteosarcomas

BACKGROUND

This systemic analysis was conducted to evaluate the efficacy and safety of an ifosfamide- containing regimen in treating patients with osteosarcoma.

METHODS

Clinical studies evaluating the efficacy and safety of Ifosfamide-containing regimen on response and safety for patients with osteosarcoma were identified by using a predefined search strategy. Pooled response rate (RR) of treatment were calculated.

RESULTS

When ifosfamide-containing regimens were evaluated, 4 clinical studies which including 134 patients with osteosarcoma were considered eligible for inclusion. Systemic analysis suggested that, in all patients, pooled RR was 44.8% (60/134) in ifosfamide-containing regimens. Major adverse effects were neutropenia, leukopenia, and fatigue inIfosfamide-containing regimens; No treatment related death occurred in cantharidin combined regimens.

CONCLUSION

This systemic analysis suggests that ifosfamide-containing regimens are associated with good response rate and acceptable toxicity in treating patients with osteosarcoma, but this result should be confirmed by randomized clinical trials.

Correlation between E-cadherin-regulated cell adhesion and human osteosarcoma MG-63 cell anoikis

PURPOSE

The aim of this study was to investigate the relationship between cell adhesion and anoikis evasion among human osteosarcoma cells (MG-63), and to further study the molecular mechanisms.

MATERIALS AND METHODS

Human osteosarcoma cells (MG-63) were assessed for apoptosis, and caspase-3, E-cadherin and β-catenin expression in EDTA and control non-EDTA groups.

RESULTS

MG-63 cells were predominantly aggregated when in suspension, and the suspended cells were more dispersed in the EDTA group. Following culture in suspension for 24 h, 48 h, or 72 h, the rates of apoptosis were 34.88%±3.64%, 59.3%±7.22% and 78.5%±5.21% in the experimental group and 7.34%±2.13%, 14.7%±3.69%, and 21.4%±3.60% in the control group, respectively. Caspase-3 expression progressively increased and E-cadherin and β-catenin were decreased in the experimental group, whereas there was no change in the control group.

CONCLUSIONS

MG-63 cells could avoid anoikis through cell adhesion, and E-cadherin might play a role in this process.

Genetic polymorphisms of interleukin-1 beta and osteosarcoma risk

PURPOSE

Osteosarcoma is the most common childhood bone cancer. Interleukin-1 beta (IL-1B) is crucially involved in osteosarcoma carcinogenesis. Whether genetic polymorphisms of IL-1B also influence osteosarcoma risk is unknown. The aim of this study was to investigate the association between IL-1B gene polymorphisms and osteosarcoma risk in Chinese Han patients.

METHODS

A hospital-based case-control study involving 120 osteosarcoma patients and 120 controls was conducted. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect three IL-1B gene polymorphisms (-31 T/C, -511 C/T and +3954 C/T) in these patients.

RESULTS

Patients with osteosarcoma had a significantly lower frequency of -31 CC genotype [odds ratio (OR) = 0.40, 95% confidence interval (CI) = 0.17-0.92; P = 0.03] and -31 C allele (OR = 0.67, 95% CI = 0.46-0.99; P = 0.04) than controls. Patients with osteosarcoma had a significantly lower frequency of -511 TT genotype (OR = 0.40, 95% CI = 0.17-0.95; P = 0.04) than controls. The +3954 C/T gene polymorphisms were not associated with a risk of osteosarcoma. When stratified by Enneking stage, tumour location, histological type, tumour metastasis of osteosarcoma and family history of cancer, no statistically significant results were found.

CONCLUSIONS

This is the first study to provide evidence for an association of IL-1B gene polymorphisms with osteosarcoma risk.

Review of the molecular pathogenesis of osteosarcoma

Treating the osteosarcoma (OSA) remains a challenge. Current strategies focus on the primary tumor and have limited efficacy for metastatic OSA. A better understanding of the OSA pathogenesis may provide a rational basis for innovative treatment strategies especially for metastases. The aim of this review is to give an overview of the molecular mechanisms of OSA tumorigenesis, OSA cell proliferation, apoptosis, migration, and chemotherapy resistance, and how improved understanding might contribute to designing a better treatment target for OSA.