Individualized chemotherapy for osteosarcoma and identification of gene mutations in osteosarcoma

Abstract

The study aims to identify novel gene mutations in osteosarcoma and to guide individualized preoperative chemotherapy for osteosarcoma based on the analysis of expression and mutations of the drug-metabolism-related genes. Twenty-eight osteosarcoma patients received individualized preoperative chemotherapy regimens. Expression levels and mutations of chemotherapy-related genes in samples collected from the patients were determined using real-time PCR and DNA sequencing, respectively. Patient sensitivity to chemotherapeutic agents was evaluated by systematic analysis of the PCR and sequencing results. Novel mutations were identified via high-throughput sequencing of 339 genes in 10 osteosarcoma samples. Individualized preoperative chemotherapy outcomes were valid for nine patients (n = 9/28, 32.1%). Chemosensitivity assays showed that all 28 patients were sensitive to ifosfamide, whereas 46.4 and 39.2% were sensitive to docetaxel and platinum, respectively. More importantly, patients receiving highly chemosensitive chemotherapy agents had better prognosis and treatment outcomes than those receiving less chemosensitive agents (P < 0.05). In addition, 39 gene mutations were detected in at least five osteosarcoma tumor samples. Analysis of the expression and mutation of drug-metabolism-related genes will aid in the design of effective individualized preoperative chemotherapy regimens for osteosarcoma. Determining the chemosensitivity of individual tumors to chemotherapeutic agents will facilitate the development of better therapeutic approaches. Individualized treatment of osteosarcoma may improve chemotherapy efficacy and the survival rate of osteosarcoma patients. High-throughput genotyping allows mapping of osteosarcoma mutations, and novel gene mutations offered new candidates for diagnosis and therapeutic targeting.

Preliminary Application of Precision Genomic Medicine Detecting Gene Variation in Patients with Multifocal Osteosarcoma

“…Because MFOS has a much worse prognosis than single lesion OS, a bone scan is indicated on the first hospital visit of a patient with an OS to determine whether there are multiple tumors. Use of chemotherapy drugs to which the tumor is sensitive according to sequencing may enable more effective chemotherapy, as has been shown for adolescent patients with single lesion OS. Patients with MFOS, whose tumors are more likely to be drug‐resistant, may benefit from drug sensitive detection, which could avert progression and prolong overall survival.…”

“…As an example, vemurafenib, a mutation‐specific BRAF inhibitor, has successfully been used to treat metastatic melanoma. With the rapid progress in gene sequencing and application of precision medicine, oncogene like HER2, c‐myc, c‐fos, MDM2, SAS, anti‐oncogenes such as TP53, Rb, p16 (expressed gene mutations of which have been implicated in the initiation and progression of metastases), CD44, matrix metalloproteinases and nm23 have also been found to be associated with the lung metastases of OS. With the help of whole gene sequencing to test tumor tissue of children and adolescent OS patients, Chen et al .…”

“…As an example, vemurafenib, a mutation-specific BRAF inhibitor, has successfully been used to treat metastatic melanoma 23,24 . With the rapid progress in gene sequencing and application of precision medicine, oncogene like HER2, c-myc, c-fos, MDM2, SAS, anti-oncogenes such as TP53, Rb, p16 (expressed gene mutations of which have been implicated in the initiation and progression of metastases), CD44, matrix metalloproteinases and nm23 have also been found to be associated with the lung metastases of OS 25,26 . With the help of whole gene sequencing to test tumor tissue of children and adolescent OS patients, Chen et al detected TP53, RB1, MYC, PTEN, ATRX, LSAMP-AS3, CCNE1, COPS3, PMP22, MAPK7, NCOR1 and UBB gene expressed mutations, mostly as single nucleotide variants (SNV), and reported that such mutations are strongly correlated with tumor characteristics, as is true of copynumber variations (CNV) [27][28][29][30][31] .…”

Identification of TIMP2 and RAX as key regulators in chemosensitive osteosarcoma

“…RD represents chemotherapy sensitivity, while SD and PD represent drug resistance. Based on this criteria [41] RT-PCR experiments were preformed on the 68 samples to validate the mRNA expression of the identi ed differentiately expressed genes (TIMP2 and BAX). Total RNA was extracted using TRIzol reagent with manufacturer's instruction (ThermoFisher Inc., USA).…”

Oridonin synergizes with Nutlin-3 in osteosarcoma cells by modulating the levels of multiple Bcl-2 family proteins

“…The apoptotic activity by Mdm2 inhibitors mainly relies on p53 activation and the upregulation of a classic pro-apoptotic p53-target genes Puma ( Supplementary Figure 2(a) and (b)). 4,5 We next investigated whether Oridonin had impact on p53 activation. Western blotting and qRT-PCR assays showed that Oridonin had no influence on the levels of Mdm2, p53, and Puma expression and also did not affect the ability of Nutlin-3 in inducing Mdm2 and p53 accumulation and Puma upregulation in OS cell lines ( Figure 5(a)-(d)).…”