Kathleen Dorritie

Spontaneous transformation of murine epithelial cells requires the early acquisition of specific chromosomal aneuploidies and genomic imbalances

Human carcinomas are defined by recurrent chromosomal aneuploidies, which result in a tissue‐specific distribution of genomic imbalances. In order to develop models for these genome mutations and to determine their role in tumorigenesis, we generated 45 spontaneously transformed murine cell lines from normal epithelial cells derived from bladder, cervix, colon, kidney, lung, and mammary gland. Phenotypic changes, chromosomal aberrations, centrosome number, and telomerase activity were assayed in control uncultured cells and in three subsequent stages of transformation. Supernumerary centrosomes, binucleate cells, and tetraploidy were observed as early as 48 hr after explantation. In addition, telomerase activity increased throughout progression. Live‐cell imaging revealed that failure of cytokinesis, not cell fusion, promoted genome duplication. Spectral karyotyping demonstrated that aneuploidy preceded immortalization, consisting predominantly of whole chromosome losses (4, 9, 12, 13, 16, and Y) and gains (1, 10, 15, and 19). After transformation, focal amplifications of the oncogenes Myc and Mdm2 were frequently detected. Fifty percent of the transformed lines resulted in tumors on injection into immunocompromised mice. The phenotypic and genomic alterations observed in spontaneously transformed murine epithelial cells recapitulated the aberration pattern observed during human carcinogenesis. The dominant aberration of these cell lines was the presence of specific chromosomal aneuploidies. We propose that our newly derived cancer models will be useful tools to dissect the sequential steps of genome mutations during malignant transformation, and also to identify cancer‐specific genes, signaling pathways, and the role of chromosomal instability in this process.

STAT transcription factors in normal and cancer stem cells

Signal transducer and activator of transcription proteins (STATs) play vital roles in the regulation of cellular proliferation and survival in normal hematopoietic cells, including hematopoietic stem cells. However, aberrant activation of STATs is commonly observed in a number of hematologic malignancies, and recent studies indicate that targeting of STATs may have therapeutic benefit in these diseases. Additional studies have provided greater understanding of the cells responsible for leukemia initiation, referred to as leukemia stem cells. Emerging evidence indicates that STATs are important in maintaining leukemia stem cells and represent a promising target for eradication of this dangerous cell population. Here we summarize what is known about normal hematopoietic stem cells and the origin of leukemic stem cells. We further describe the roles of STAT proteins in these cell populations, as well as current progress toward the development of novel agents and strategies for targeting the STAT proteins.

Advanced molecular cytogenetics in human and mouse

Fluorescence in situ hybridization, spectral karyotyping, multiplex fluorescence in situ hybridization, comparative genomic hybridization, and more recently array comparative genomic hybridization, represent advancements in the field of molecular cytogenetics. The application of these techniques for the analysis of specimens from humans, or mouse models of human diseases, enables one to reliably identify and characterize complex chromosomal rearrangements resulting in alterations of the genome. As each of these techniques has advantages and limitations, a comprehensive analysis of cytogenetic aberrations can be accomplished through the utilization of a combination approach. As such, analyses of specific tumor types have proven invaluable in the identification of new tumor-specific chromosomal aberrations and imbalances (aneuploidy), as well as regions containing tumor-specific gene targets. Application of these techniques has already improved the classification of tumors into distinct categories, with the hope that this will lead to more tailored treatment strategies. These techniques, in particular the application of tumor-specific fluorescence in situ hybridization probes to interphase nuclei, are also powerful tools for the early identification of premalignant lesions.

Leukapheresis in patients newly diagnosed with acute myeloid leukemia

Hyperleukocytosis is present in 5 to 20 percent of patients with newly diagnosed acute myeloid leukemia (AML). The management of hyperleukocytosis, when symptoms of leukostasis occur, includes intensive supportive care and interventions for rapid cytoreduction. Leukapheresis is a rapid and effective means of cytoreduction and has been used in AML patients. In the current study, we evaluated the outcomes of 68 newly diagnosed AML patients that underwent leukapheresis and the effects of leukapheresis on various laboratory parameters. A total of 127 leukapheresis cycles were performed. The median number of leukapheresis cycles was 2 (range, 1-8). The overall survival for all patients was 4.2 months (95% CI 1.2-9.7 months). The median overall survival for patients who achieved complete remission after induction chemotherapy was significantly higher (19.1 months [95% CI 12.1-41.8 months]) than patients that did not achieve complete remission (0.46 months [95% CI 0.33-0.99 months]). Stepwise logistic regression demonstrated that elevated number of peripheral blasts, low platelet count and elevated bilirubin at AML diagnosis were predictive of death within a week. Leukapheresis was effective in reducing the peripheral blood leukocytes and leukemia blasts and was a safe procedure with regard to organ function, coagulation parameters, red blood cells and platelet count. The high initial response rates in newly diagnosed AML patients fit to receive intensive chemotherapy suggest that leukapheresis could be beneficial in reducing the complications associated with hyperleukocytosis until systemic intensive chemotherapy commences.

IV pentamidine for primary PJP prophylaxis in adults undergoing allogeneic hematopoietic progenitor cell transplant.

IV pentamidine for primary PJP prophylaxis in adults undergoing allogeneic hematopoietic progenitor cell transplant

Peri‐transplant Clostridium difficile infections in patients undergoing allogeneic hematopoietic progenitor cell transplant

Clostridium difficile infections (CDI) remain the leading cause of infectious diarrhea among hospitalized patients in this country. Patients with hematologic malignancies, especially those who undergo hematopoietic progenitor cell transplants are particularly at risk for developing CDI. One hundred and forty seven consecutive allogeneic hematopoietic progenitor cell transplants were analyzed for peri‐transplant Clostridium difficile infections (PT‐CDI). Sixteen patients (11%) developed PT‐CDI (Median time = 7 days after transplant). The probability for developing PT‐CDI during the peri‐transplant period was 12.3%. History of CDI was strongly associated with the development of PT‐CDI (P = 0.008) (OR = 5.48) (P = 0.017). These patients also developed PT‐CDI much earlier than in those without a history (median 1 day vs. 8 days, P = 0.03). The probability for developing PT‐CDI for those with a history was 39%. There was a trend toward significance (P = 0.065) between matched related donor grafts and the development of PT‐CDI (OR = 0.245) (P = 0.08). Age, sex, diagnosis, transplant preparative regimens, Graft‐versus‐host disease (GVHD) prophylaxis, grade 3/4 acute GVHD, or use of antimicrobials within 8 weeks of transplant were not associated with PT‐CDI. Non‐CDI‐related deaths occurred in one patient in the PT‐CDI group and nine in the group without PT‐CDI. In the remaining 139 patients, the length of hospital stay for those with PT‐CDI was significantly longer than those without (mean 27 days vs. 22 days; P = 0.02). Am. J. Hematol. 91:291–294, 2016.

Histopathology of Graft-vs-Host Disease of Gastrointestinal Tract and Liver An Update

OBJECTIVES Graft-vs-host disease (GVHD) is a donor T-cell-mediated disorder affecting the recipients skin, gastrointestinal tract, lungs, and liver. It complicates up to 70% of hematopoietic cell transplantation and is associated with high morbidity and mortality rates. METHODS An extensive review of the literature has been performed to include the most current consensus on the histopathologic diagnosis of gastrointestinal and liver GVHD. RESULTS In this review, we present an overview of GVHD, with emphasis on the histopathologic evaluation of gastrointestinal and liver specimens, including the most important differential diagnoses and possible pitfalls. CONCLUSIONS Histopathologic examination remains the mainstay of diagnosis of gastrointestinal and liver GVHD and is interpreted in conjunction with clinical and laboratory data.

Inferior outcome after allogeneic transplant in first remission in high-risk AML patients who required more than two cycles of induction therapy.

While some patients with high‐risk acute myeloid leukemia (AML) require one or two cycles of induction chemotherapy to achieve a complete remission (CR), others require more than two cycles. We examined the outcomes of patients with high‐risk AML who received allogeneic HPC transplant in CR1. Forty five consecutive high‐risk AML patients in CR1 were included. All 45 patients had adverse cytogenetics, FLT 3 mutations, or secondary AML. Group A patients (n = 33) received one or two cycles, and Group B (n = 12) three or more cycles of induction chemotherapy. The patients were comparable in age, sex, white cell count at presentation, and time from diagnosis and from last chemotherapy to transplant. The 100‐day mortality rate was higher in Group B patients (50% vs. 9%, P = 0.006). They had a higher non‐relapse mortality (33% vs. 6%, P = 0.035) and a longer length of hospital stay from the day of stem cell infusion (median 21 vs. 20, P = 0.02; third quartile 22 vs. 28, P = 0.02). There was also a trend toward inferior event‐free survival and overall survival. High‐risk AML patients undergoing allogeneic transplant in CR1 after three or more cycles of induction chemotherapy have an inferior outcome and higher mortality when compared to those who only needed one or two cycles of induction chemotherapy. Novel strategies are needed to reduce the transplant‐related mortality in high‐risk AML patients needing more than two cycles of induction chemotherapy prior to allogeneic transplant in CR1. Am. J. Hematol. 90:715–718, 2015.

Mitoxantrone and Etoposide for the Treatment of Acute Myeloid Leukemia Patients in First Relapse.

Relapsed acute myeloid leukemia (AML) represents a major therapeutic challenge. Achieving complete remission (CR) with salvage chemotherapy is the first goal of therapy for relapsed AML. However, there is no standard salvage chemotherapy. The current study evaluated outcomes and prognostic factors for achievement of CR in 91 AML patients in first relapse who were treated with the mitoxantrone-etoposide combination regimen. The overall response rate (CR and CRi) was 25%. Factors that were associated with a lower rate of CR included older age, shorter duration of first CR, low hemoglobin, and low platelet count. The median overall survival for all patients was 7.4 months. The survival of patients who achieved CR and underwent allogeneic hematopoietic cell transplantation (allo-HCT) was higher than those who achieved CR and did not undergo allo-HCT (35.3 months vs. 16.8 months, p = 0.057). The median duration of relapse-free survival was 12.7 months in the patients achieving CR. Older age at the time of AML relapse was associated with worse overall survival. The all-cause 4-week mortality rate was 4%, and the all-cause 8-week mortality rate was 13%. The findings of this study underscore the need for newer therapies, especially those that will improve the ability for patients with relapsed AML to achieve CR and to allow them to receive additional therapies.

Location matters in early stage nodal diffuse large B-cell lymphoma

Konstantinos Lontos , Anastasia Tsagianni, Jian-Min Yuan, Daniel P. Normolle, Michael Boyiadzis, Jing-Zhou Hou, Steven H. Swerdlow and Kathleen A. Dorritie Division of Hematology/Oncology, UPMC, Pittsburgh, PA, USA; Division of Internal Medicine, UPMC, Pittsburgh, PA, USA; Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Hillman Cancer Center, Biostatistics Facility, Pittsburgh, PA, USA; UPMC Hillman Cancer Center, Pittsburgh, PA, USA; Department of Pathology, Division of Hematopathology, UPMC, Pittsburgh, PA, USA