MLL partner genes in secondary acute lymphoblastic leukemia: Report of a new partner PRRC1 and review of the literature

Secondary acute lymphoblastic leukemia (sALL) following chemotherapy and/or radiotherapy of previous malignancies represents 2–10% of all cases of ALL. A 72-year-old female patient was diagnosed with acute lymphoblastic leukemia following chemotherapy for a diffuse large B cell lymphoma. Banding cytogenetics showed a t(t(5;11)(q23–31;q23) in 20 of the 21 metaphases examined and fluorescent in situ hybridization confirmed rearrangement of MLL. Long distance inverse-polymerase chain reaction revealed an in-frame fusion between 5′MLL and 3′PRRC1. Sixty-five cases of sALL associated with 11q23/MLL rearrangement, including 47 with a t(4;11)(q21;q23), were retrieved from the literature. Drug regimen used to treat the primary neoplasm was available for 54 patients; 52 had received a topoisomerase II inhibitor, known to induce MLL rearrangement.     

A two-phase case-control study for colorectal cancer genetic susceptibility: candidate genes from chromosomal regions 9q22 and 3q22

Background:

Colorectal cancer (CRC) is the second cause of cancer-related death in the Western world. Much of the CRC genetic risk remains unidentified and may be attributable to a large number of common, low-penetrance genetic variants. Genetic linkage studies in CRC families have reported additional association with regions 9q22–31, 3q21–24, 7q31, 11q, 14q and 22q. There are several plausible candidate genes for CRC susceptibility within the aforementioned linkage regions including PTCH1, XPA and TGFBR1 in 9q22–31, and EPHB1 and MRAS in 3q21–q24.

Methods:

CRC cases and matched controls were from EPICOLON, a prospective, multicentre, nationwide Spanish initiative, composed of two independent phases. Phase 1 corresponded to 515 CRC cases and 515 controls, whereas phase 2 consisted of 901 CRC cases and 909 controls. Genotyping was performed for 172 single-nucleotide polymorphisms (SNPs) in 84 genes located within regions 9q22–31 and 3q21–q24.

Results:

None of the 172 SNPs analysed in our study could be formally associated with CRC risk. However, rs1444601 (TOPBP1) and rs13088006 (CDV3) in region 3q22 showed interesting results and may have an effect on CRC risk.

Conclusions:

TOPBP1 and CDV3 genetic variants on region 3q22 may modulate CRC risk. Further validation and meta-analysis should be undertaken in larger CRC cohorts.     

EDG3 and SHC3 on chromosome 9q22 are co-amplified in human ependymomas

By qPCR we found that EDG3 and SHC3 were amplified in 60% of ependymomas but none in choroid plexus papillomas. In ependymomas EDG3 and SHC3 amplification increased Shc3 protein levels while EDG3 was less affected. Both proteins were co-immunoprecipitated from ependymoma and Shc3 was tyrosine phosphorylated thus presumably active. We showed by digestion with N-glycosidase-F that EDG3 was glycosylated indicating that EDG3 protein was not retained in the endoplasmic reticulum. The co-immunoprecipitation of Shc3 and EDG3 proteins from ependymomas with amplification of SHC3 and EDG3 genes suggests that the two proteins co-operate and are important for ependymomas in vivo.     

Prediction for response duration to epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR mutated never smoker lung adenocarcinoma

Objectives

Among non-small cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations, ∼20–30% exhibit de novo resistance to EGFR-tyrosine kinase inhibitor (TKI). The aim of this study was to examine whether mutations in the EGFR-downstream genes may be associated with de novo resistance to EGFR-TKIs in EGFR mutation-positive patients.

Materials and methods

Sixty-eight never-smoker adenocarcinoma patients with an activating EGFR mutation were included in the mutational analysis and 55 patients treated with EGFR-TKIs were analyzed for the treatment outcomes to EGFR-TKIs. We concurrently analyzed mutations in PIK3CA, PTEN, AKT and STK11, which are all EGFR-downstream genes. Mutations in PIK3CA, PTEN, AKT, and STK11 were analyzed by polymerase chain reaction-based sequencing.

Results

PIK3CA mutations were detected in 4.4% (3/68) of patients, PTEN mutations in 16.1% (11/68), AKT mutations in 5.9% (4/68), and STK11 mutations in 13.2% (9/68). One patient with an activating exon 21 L858R mutation concomitantly had an exon 20 T790M mutation in EGFR. The proportion of patients who had mutations in EGFR-downstream genes was 32.4% (22/68). When we analyzed the treatment outcome of 55 patients treated with EGFR-TKI, the presence of mutations in EGFR-downstream genes correlated with a poor overall response rate to EGFR-TKIs (63.6 vs.14.5% in patients with mutation in EGFR-downstream gene, P < 0.0001), shorter median progression-free survival (12.0 vs. 3.0 months, P = 0.060), and shorter median overall survival (18.9 vs. 25.0 months, P = 0.048).

Conclusion

Mutations in the EGFR-downstream genes may confer resistance to EGFR-TKIs and result in poor treatment outcomes in never-smoker adenocarcinoma patients with activating EGFR mutations.     

T(1;21;8)(p34;q22;q22): a novel variant of t(8;21) in acute myeloblastic leukemia with maturation

The complex variants of t(8;21) involving chromosomes 8 and 21 as well as another chromosome account for approximately 3% of acute myeloid leukemia patients. We report here a 30-year-old male patient with AML-M2. Fluorescence in situ hybridization analysis using dual-color fluorescence ETO and AML1 probes located at 8q22 and 21q22 respectively showed an AML1/ETO fusion signal on the derivative chromosome 8. Whole chromosome painting probes were used for chromosome 1, 8 and 21 and revealed a three-way translocation (1;21;8)(p34 ~ p35;q22;q22). Involvement of chromosome region 1p34 has never been reported earlier, although region 1p35 as a variant in AML with t(8;21) has been reported with an AML1/ETO fusion signal on the 1p35 rather than der(8). In conclusion, combining conventional karyotype, FISH or RT-PCR analyses are a rational strategy for the identification of the complex variants of t(8;21) translocation which could be critical events responsible for leukemogenesis.     

伴t(8;21)(q22;q22)易位的急性双表型白血病的临床研究

Objective： To report 4 cases of biphenotypic acute leukemia （BAL） with t（8;21）（q22;q22）, and analyze the characteristics of morphology, immune phenotype, chromosome karyotype （MIC） and clinical manifestations. Methods： The BAL patients with t（8;21）（q22;q22） （group A） were compared with the randomly selected BAL patients with other clonical chromosomal changes （group B） and acute myeloid leukemia M2 cases with t（8;21）（q22;q22） （group C） in MIC and clinical features. Results： BAL with t（8;21）（q22;q22） showed acute myeloid leukemia with high percentages of blast cells morphologically; revealed co-positive to B-lymphoid and myeloid lineages, frequent and high expressions of CD34 and CD33; were responsive to chemotherapy for myeloid and lymphocytic leukemia simultaneously well. Conclusion： A new subset of BAL with t（8;21）（q22;q22） was reported, and this suggests that the leukemia colony with t（8;21）（q22;q22） might originate from early phase of hematopoiesis.     

伴t(8;21)(q22;q22)易位的急性双表型白血病的临床研究

Objective: To report 4 cases of biphenotypic acute leukemia (BAL) with t(8;21)(q22;q22), and analyze the characteristics of morphology, immune phenotype, chromosome karyotype (MIC) and clinical manifestations. Methods: The BAL patients with t(8;21)(q22;q22) (group A) were compared with the randomly selected BAL patients with other clonical chromosomal changes (group B) and acute myeloid leukemia M2 cases with t(8;21)(q22;q22) (group C)in MIC and clinical features.Results: BAL with t(8;21)(q22;q22) showed acute myeloid leukemia with high percentages of blast cells morphologically;revealed co-positive to B-lymphoid and myeloid lineages, frequent and high expressions of CD34 and CD33; were responsive to chemotherapy for myeloid and lymphocytic leukemia simultaneously well. Conclusion: A new subset of BAL with t(8;21)(q22;q22) was reported, and this suggests that the leukemia colony with t(8;21)(q22;q22) might originate from early phase of hematopoiesis.     

EGFR and EML4-ALK gene mutations in NSCLC: a case report of erlotinib-resistant patient with both concomitant mutations

The fusion gene EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) was recently identified as a novel genetic alteration in non-small cell lung cancer (NSCLC). EML4-ALK translocations correlate with specific clinical and pathological features, in particular lack of EGFR and K-ras mutations, and may be associated with resistance to EGFR tyrosine-kinase inhibitors (TKIs). Here, we report a case of a patient with a concomitant EGFR mutation and ALK translocation resistant to erlotinib. Considering this report, ALK status should be investigated in unexplained cases of EGFR-TKI-resistance of EGFR mutated NSCLCs.     

A novel translocation t(3;22)(q21;q11) involving 3q21 in myelodysplastic syndrome-derived overt leukemia with thrombocytosis

We report here a novel translocation t(3;22)(q21;q11) in myelodysplastic syndrome (MDS)-derived overt leukemia with thrombocytosis. A 44-year-old female was initially diagnosed as MDS with a low platelet count and normal karyotype. After 4 months, blood leukemic cells and platelets rapidly increased concomitantly and a diagnosis of acute myeloblastic leukemia (AML M1) was made. Chromosome analysis showed 46, XX, t(3;22)(q21;q11) in 14 of 20 metaphases. Fluorescence in situ hybridization analysis confirmed both the der(3)t(3;22) and the der(22)t(3;22). Our results suggest that unidentified gene(s) at 3q21 breakpoint may be implicated in the pathogenesis of abnormal thrombopoiesis as observed in the 3q21q26 syndrome.     

Translocation t(9;22)(q22;q12) is a primary cytogenetic abnormality in extraskeletal myxoid chondrosarcoma

The cytogenetic and in vitro growth characteristics of 3 cases of extraskeletal myxoid chondrosarcoma (EMC) are described. In cell culture, the tumor cells retained the immunocytochemical and ultrastructural characteristics of EMC. Cytogenetically, 2 of the cases showed an apparently identical t(9;22)(q22;q12). In one case, the t(9;22) was found together with a dup(1)(q12q44), and in the other case it was found together with several other aberrations. The third case had an inv(10)(p11.2q22) as the sole karyotypic abnormality. Of 4 cases of EMC previously analyzed, 2 showed a t(9;22)(q22;q11–12) and one case a t(9;22;15)(q31;q12.2;q25). Thus, 5 out of 7 cases of EMC showed recombination between 9q22–31 and 22q11–12, indicating that this represents a tumor specific abnormality. The breakpoints on 22q were in all 5 cases Cytogenetically indistinguishable from those seen in Ewing's sarcoma with t(11;22), clear-cell sarcoma with t(12;22), and desmoplastic small round cell tumors with t(11;22). Molecular cloning of these translocation breakpoints revealed involvement of the EWS gene (located at 22q12) in all 3 tumor types. These observations raise the intriguing question of whether the EWS gene might also be involved in the t(9;22) in EMC. © 1995 Wiley-Liss, Inc.