Our laboratory-developed CEBNX workflow shows high coverage and thus overcomes the challenges associated with amplification efficiency and low coverage of Therefore, our assay is suitable for deployment in the clinical laboratory.

BackgroundGermline mutations in the RUNX1 transcription factor give rise to a rare autosomal dominant genetic condition classified under the entity: Familial Platelet Disorders with predisposition to Acute Myeloid Leukaemia (FPD/AML). While several studies have identified a myriad of germline RUNX1 mutations implicated in this disorder, second-hit mutational events are necessary for patients with hereditary thrombocytopenia to develop full-blown AML. The molecular picture behind this process remains unclear. We describe a patient of Malay descent with an unreported 7-bp germline RUNX1 frameshift deletion, who developed second-hit mutations that could have brought about the leukaemic transformation from a pre-leukaemic state. These mutations were charted through the course of the treatment and stem cell transplant, showing a clear correlation between her clinical presentation and the mutations present.Case presentationThe patient was a 27-year-old Malay woman who presented with AML on the background of hereditary thrombocytopenia affecting her father and 3 brothers. Initial molecular testing revealed the same novel RUNX1 mutation in all 5 individuals. The patient received standard induction, consolidation chemotherapy, and a haploidentical stem cell transplant from her mother with normal RUNX1 profile. Comprehensive genomic analyses were performed at diagnosis, post-chemotherapy and post-transplant. A total of 8 mutations (RUNX1, GATA2, DNMT3A, BCORL1, BCOR, 2 PHF6 and CDKN2A) were identified in the pre-induction sample, of which 5 remained (RUNX1, DNMT3A, BCORL1, BCOR and 1 out of 2 PHF6) in the post-treatment sample and none were present post-transplant. In brief, the 3 mutations which were lost along with the leukemic cells at complete morphological remission were most likely acquired leukemic driver mutations that were responsible for the AML transformation from a pre-leukemic germline RUNX1-mutated state. On the contrary, the 5 mutations that persisted post-treatment, including the germline RUNX1 mutation, were likely to be part of the preleukemic clone.ConclusionFurther studies are necessary to assess the prevalence of these preleukemic and secondary mutations in the larger FPD/AML patient cohort and establish their prognostic significance. Given the molecular heterogeneity of FPD/AML and other AML subtypes, a better understanding of mutational classes and their involvement in AML pathogenesis can improve risk stratification of patients for more effective and targeted therapy.

Background: TP53 gene is a tumour suppressor gene located in the short arm of chromosome 17. TP53 plays a pivotal role in maintaining genomic stability in response to DNA damage. It is mutated in more than 50% of the human cancer. TP53 mutation (TP53mut) is commonly associated with therapy-related acute myeloid leukemia (AML) and complex karyotype. The incidence of TP53mutn was between 5-10% in de novo AML. This study described the clinicopathologic features of TP53mut AML and their clinical outcome in an Asian cohort.Method: 166 consecutively cell-banked marrow samples of AML were tested for TP53 mutations using a next generation sequencing platform. Baseline disease characteristic and clinical outcomes were retrospectively collected with approval granted by institutional review board.Results: 9/166 had TP53mut (5.4%). 6/9 of TP53mut AML was associated with complex karyotype (p<0.001). The remaining 3 cases were two acute promyelocytic leukemia (APML) and one with normal cytogenetics. TP53mut was mutually exclusive with FLT3 mutation. Two cases had concomitant NPM1 mutation and another two had ASXL1 mutation. TP53mut AML appeared to be associated with TET2 mutation (3/9, 33.3%) compared to 10.2% of the TP53wt (p=0.069). TP53mut AML had a lower CR rate compared to TP53wt (28.6% vs 84.3%, p=0.003). Only two cases achieved CR, one was an APML who remained in continuous remission after 4 years. The other case achieved CR after allogeneic transplant but, relapsed 8 months later. TP53mut AML was significantly associated with inferior OS compared to TP53wt (p=0.001). 0.8 months (95%CI: 0.159 -1.484) and 36.8 months (95%CI: 0.000 -92.676) respectively. It remains an independent predictor of OS in multivariate analysis that include cytogenetic risk, WBC, LDH and BM blasts (HR 43.07, 95%CI: 6.87-272.41, p<0.001). Conclusion:Our results confirmed the extremely dismal prognosis of TP53mut AML. TP53 mutation testing should be included as part of the pre-chemotherapy workout since this is not a standard practice as yet. The significance of its association with TET2 mutation requires further exploration in a larger study cohort.

Aim: To investigate the impact of oxaliplatin resistance on the cellular characteristics and miRNA expression pattern in colorectal cancer cells. Methods: A stable oxaliplatin-resistant colorectal cancer HCT116 cell line was established by exposure to increasing doses of oxaliplatin. Alterations in cytotoxicity, migration, invasion and tumorsphere formation were assessed by MTS assay, modified Boyden chamber assay, and colonosphere assay respectively. The miRNAome of the oxaliplatin-resistant HCT116 cells was analyzed using the TaqMan PCR Human miRNA array. Upregulated miRNAs from the PCR array were validated by real-time reverse transcription-quantitative PCR (RT-qPCR). Results: Oxaliplatin-resistant HCT116 cells exhibited higher migration, invasion and tumorsphere formation compared to parental oxaliplatin-sensitive HCT116 cells. The oxaliplatin-resistant cells showed a distinct miRNA expression profile compared to the parental cells. The expression of miR-601, miR-222, miR-202 and miR-25 were verified by RT-qPCR to be increased in resistant cells. Bioinformatics analyses were used to identify potential target mRNAs of these 4 miRNAs. Conclusion: Results presented in this study provide evidence that oxaliplatin-resistance induces phenotypic changes in colorectal cancer and alterations in miRNA expression. Functional studies on the miRNAs and their target mRNA may enable the discovery of functional pathways to chemoresistance in colorectal cancer.