Disruption of the anaphase-promoting complex confers resistance to TTK inhibitors in triple-negative breast cancer.

TTK protein kinase (TTK), also known as Monopolar spindle 1 (MPS1), is a key regulator of the spindle assembly checkpoint (SAC), which functions to maintain genomic integrity. TTK has emerged as a promising therapeutic target in human cancers, including triple-negative breast cancer (TNBC). Several TTK inhibitors (TTKis) are being evaluated in clinical trials, and an understanding of the mechanisms mediating TTKi sensitivity and resistance could inform the successful development of this class of agents. We evaluated the cellular effects of the potent clinical TTKi CFI-402257 in TNBC models. CFI-402257 induced apoptosis and potentiated aneuploidy in TNBC lines by accelerating progression through mitosis and inducing mitotic segregation errors. We used genome-wide CRISPR/Cas9 screens in multiple TNBC cell lines to identify mechanisms of resistance to CFI-402257. Our functional genomic screens identified members of the anaphase-promoting complex/cyclosome (APC/C) complex, which promotes mitotic progression following inactivation of the SAC. Several screen candidates were validated to confer resistance to CFI-402257 and other TTKis using CRISPR/Cas9 and siRNA methods. These findings extend the observation that impairment of the APC/C enables cells to tolerate genomic instability caused by SAC inactivation, and support the notion that a measure of APC/C function could predict the response to TTK inhibition. Indeed, an APC/C gene expression signature is significantly associated with CFI-402257 response in breast and lung adenocarcinoma cell line panels. This expression signature, along with somatic alterations in genes involved in mitotic progression, represent potential biomarkers that could be evaluated in ongoing clinical trials of CFI-402257 or other TTKis.

Childhood cancer epidemiology in New Mexico's American Indians, Hispanic whites, and non-Hispanic whites, 1970-82.

The statewide population-based New Mexico Tumor Registry identified 473 malignant tumors among children of ages 0-14 years, during the period 1970-82. There were 235 non-Hispanic whites (50%), 189 Hispanic whites (40%), 38 American Indians (8%), and 11 other nonwhites (2%). The average annual age-adjusted incidence rates per million for non-Hispanic whites were 138.6 for males and 108.3 for females; for Hispanic whites, the rates were 108.5 for males and 80.9 for females; for American Indians, the rates were 75.5 for males and 78.0 for females. The incidence rates for all sites of cancer combined were lower for Hispanics and American Indians than for New Mexico's non-Hispanic whites and U.S. whites. Leukemia was the most common cancer in all racial-ethnic groups. In comparison with U.S. whites, American Indians were at low risk for leukemias, lymphomas, central nervous system (CNS), sympathetic nervous system (SNS), and kidney tumors and were at high risk for retinoblastoma, bone, and sex organ tumors. Hispanics were at low risk for CNS, SNS, kidney, sex organ, and liver tumors. Hispanic and non-Hispanic white males both were at increased risk for melanoma.

Multidrug resistance-1 (MDR1) expression and functional dye/drug efflux is highly correlated with the t(8;21) chromosomal translocation in pediatric acute myeloid leukemia.

Resistance to chemotherapy is a major problem in acute myeloid leukemia (AML). An important resistance mechanism in adult AML is active drug efflux mediated by the multidrug resistance protein-1 (MDR1). To determine if MDR1 is important in childhood AML, we examined MDR1 expression and functional dye/drug efflux in 20 pediatric/adolescent AML patients; results were correlated with cytogenetics and clinical outcome. Using flow cytometry, MDR1 protein expression on the leukemic blasts was measured with the antibody MRK16, while efflux was measured by extrusion of the fluorescent dye DiO(C2)3 in the presence/absence of cyclosporin A (CsA). Six of 20 cases expressed MDR1. While all six MDR1+ cases were efflux+, three of 14 MDR1- cases also demonstrated efflux. Both MDR1 and efflux were strongly correlated with the t(8;21). All six MDR1 +/efflux+ cases and 2/3 MDR1 -/efflux+ cases had a t(8;21), while no MDR1-/efflux- cases had a t(8;21) (P < 0.0005). This correlation between MDR1, efflux, and the t(8;21) in pediatric AML was not found in 11 adult t(8;21) cases similarly studied. Although the clinical relevance of MDR1 in pediatric AML awaits larger studies, our results suggest a biologic subset of pediatric AML patients may benefit from regimens which include MDR1-reversing agents or non-MDR1 substrates.

Rhizopus osteomyelitis. A case report and review.

Mucormycosis osteomyelitis has previously been described exclusively in association with contiguous infections of rhinocerebral mucormycosis. In a patient with corticosteroid-dependent neutropenia and anemia osteomyelitis of the femur developed caused by the Mucoraceae Rhizopus. Although a primary focus was not identified, we believe this infection was hematogenous in origin. Mitogen stimulation to phytohemagglutinin (PHA) of the patient's lymphocytes revealed depressed cellullar immunity; however, there was specific response to Rhizopus extract. Treatment with systemic amphotericin B prevented further progression of the infection. A review of mucormycosis osteomyelitis is presented.

EWS and WT-1 gene fusion in desmoplastic small round cell tumor of the abdomen.

Chromosome translocations found in neoplasms often result in the creation of hybrid genes encoding chimeric proteins. This case study describes a patient with desmoplastic small round cell tumor (DSRCT) of the abdomen, an aggressive neoplasm characterized by translocation of chromosomes 11 and 22. Southern hybridization showed that the Ewing sarcoma gene (EWS) gene was rearranged in the DSRCT. Reverse transcriptase-polymerase chain reaction analysis of tumor cell RNA revealed that exons 1 to 7 of the EWS gene were joined to exons 8 to 10 of the Wilms' Tumor-1 (WT-1) gene resulting in the production of a chimeric message. The WT-1 and EWS genes encode DNA and RNA binding proteins involved in Wilms' tumor and Ewing sarcoma pathogenesis, respectively. The fusion of these two genes in DSRCT results in the production of a putatively oncogenic protein composed of the zinc finger DNA binding domains of WT-1 linked to potential transcriptional regulatory domains of EWS. DNA sequencing revealed the genomic breakpoints of translocation on chromosomes 11 and 22. The genomic breakpoint on chromosome 22 occurred in EWS intron 7 just 2 nucleotides 3' of exon 7. Polymerase chain reaction-based assays were developed that could detect the fused genes in the DSRCT tumor using either RNA or genomic DNA. The potential diagnostic use of these assays is discussed.

Cavitating primary pulmonary fibrosarcoma in a child.

Primary pulmonary sarcomas are rare tumors at all ages. They are usually solid and often remain silent until large. Prognosis is related to size and histologic characteristics. Curative efforts have been directed toward complete surgical removal. Presented in this report is an 11-year-old girl who was thought to have a bronchogenic cyst. At operation a 14 cm cavitating primary pulmonary fibrosarcoma was found, which was incompletely resected. The combined treatment modalities of surgical therapy and chemotherapy have resulted in a disease-free period of 36 months.

A comparative analysis of cytoplasmic mu (C mu) expression in acute lymphoblastic leukemia by molecular and immunologic techniques. Identification of leukemia cases expressing C mu mRNA transcripts in the absence of detectable C mu proteins.

Among acute lymphoblastic leukemias derived from the B-cell lineage, the subset of cases expressing cytoplasmic mu heavy chain proteins (C mu) in the absence of surface immunoglobulin has been designated pre-B-cell acute lymphoblastic leukemia. This group, traditionally identified using immunologic smear techniques, has been associated with a poor prognosis in some series. In a comparative study, 25 cases of B-lineage acute lymphoblastic leukemia were analyzed for C mu expression using molecular and immunologic techniques. RNA derived from cryopreserved blast cells was hybridized in both Northern and slot-blot analyses using a probe (pBZ311) containing four exons of the human immunoglobulin heavy chain mu constant region gene. Expression of C mu proteins was assessed simultaneously by slide immunofluorescence and flow cytometric techniques in all samples. These studies were correlated with immunoglobulin heavy and light chain gene rearrangements, cell-surface immunophenotype, cytogenetics, and other clinicopathologic features. C mu mRNA transcripts were detected in 14 of 25 cases, whereas C mu proteins were detected in only 9 of these cases using flow cytometric techniques. Only four of these nine cases were positive by slide immunofluorescence techniques. These studies imply that molecular and flow cytometric techniques may be a more sensitive means to assess C mu expression. The identification of five cases that expressed C mu mRNA transcripts in the absence of detectable C mu proteins also suggests that molecular techniques may be valuable in identifying a unique subgroup of pre-B-cell acute lymphoblastic leukemia cases that contain C mu mRNA transcripts, but lack C mu proteins.

Do random (non-clonal) chromosome abnormalities in bone marrow predict a clone to come? Southwestern Oncology Group of Leukemia Cytogenetics Subcommittee.

The biologic significance of clonal karyotypic abnormalities in human neoplasms is becoming better understood, but the significance of rare chromosomal aberrations is uncertain. Useful, yet arbitrary, cytogenetic definitions of a clone have been established and cases with a frequency of chromosome aberrations less than the accepted convention are explained by random loss, karyotypic instability/evolution, or other technical artifact. Are non-clonal chromosomal abnormalities that may predict future clinically significant clones being ignored? A brief case report is presented raising two such issues in the same myelodysplastic patient. This child had monosomy 7 and, later, trisomy 8, as well as increased numerical/structural aberrations seeming to predict relapse. Preliminary data from the Southwestern Oncology group is also presented. Non-clonal data should be included, when appropriate, in the clinical report.

Differences among raters evaluating the success of EMLA cream in alleviating procedure-related pain in children with cancer.

We evaluated the analgesic efficacy of EMLA cream after repeated bone marrow aspirations or lumbar punctures (LPs) in children with cancer, and compared the ratings among patients, their parents, physicians, and nurses. Data from LPs were analyzed at the last procedure without EMLA (T1) and the first and last procedures with EMLA (T2 and T3). Friedman's nonparametric analysis of variance was used for statistical analysis. A total of 272 procedures in 29 children were analyzed. For 179 procedures without EMLA, physicians rated pain lower than other raters, and for the 93 with EMLA physicians rated pain less than the children. Children rated pain at T2 lower than at T1 or T3. Physicians rated pain at T2 less than at T3. Both children and physicians rated pain at T3 as not different from that at T1. No differences were noted at these time points for other raters in LP distress ratings, or in bone marrow aspiration pain or distress ratings. Thus EMLA was associated with decreased pain ratings for LPs, but this effect was not sustainable with repeated procedures. The cream alone should not be relied on to control pain of bone marrow aspiration or repeated LPs in children. Physicians underestimated pain, which may have implications for undertreatment in this patient population.

Practical approach to the investigation of neutropenia.

This article discusses the evaluation of a patient for possible neutropenia. An evaluation must include an integration of complex factors such as age- and race-related normal ranges for absolute neutrophil count, an assessment of other hematopoietic elements in blood, an investigation for possible underlying infections, an examination for splenomegaly, and an evaluation for evidence of recurrent infections or family history suggestive of a constitutional neutropenic disorder.

Health care outcomes case study: Febrile neutropenia.

A case study of the clinical and economic impact of filgrastim in cancer patients in the home care setting is described. The risk of febrile neutropenia is greatly reduced when filgrastim therapy is begun prophylactically after a course of antineoplastic drug therapy. Such use of filgrastim may also reduce the need for hospitalization, prevent mucositis, and enable the next course of chemotherapy to be administered on schedule. Investigators at the University of New Mexico, noting studies showing merit in early hospital discharge of pediatric cancer patients with febrile neutropenia, decided to take the approach a step further by treatment febrile neutropenia entirely at home. Patients seen in the pediatric oncology clinic at the university hospital were considered candidates for home treatment if they had stable vital signs, were already receiving filgrastim after the completion of cancer chemotherapy, and lived within one hour of the hospital. Six cancer patients 2-17 years of age were studied between August 1992 and February 1994. These patients had 16 episodes of febrile neutropenia that were treated at home. The drug regimen consisted of prophylactic filgrastim (begun the day after completion of a course of antineoplastic therapy) and ceftazidime (when febrile neutropenia developed). None of the children were readmitted to the hospital. Infections resolved within 12 days in all cases. The total charge for treating the 16 episodes at home was $22,400 (drug charge for ceftazidime, visits by nurses, infusion-pump rental, and ancillary charges). The total charge for hospital treatment of these episodes would be $112,924 (bed charge and pharmacy charge). The difference suggests a potential savings of $90,524 from home care for this small group of patients. Treating febrile neutropenia in pediatric cancer patients at home is effective and cost-efficient if the patients are clinically stable and prophylactic filgrastim therapy has been started after the completion of cancer chemotherapy.

The single-patient room in the NICU: maternal and family effects.

OBJECTIVE: To explore differences in maternal factors, including visitation and holding, among premature infants cared for in single-patient rooms (SPR) compared with open-bay in the neonatal intensive care unit (NICU). STUDY DESIGN: A total of 81 premature infants were assigned to a bed space in either the open-bay area or in a SPR upon NICU admission, based on bed space and staffing availability in each area. Parent visitation and holding were tracked through term equivalent, and parents completed a comprehensive questionnaire at discharge to describe maternal health. Additional maternal and medical factors were collected from the medical record. Differences in outcome variables were investigated using linear regression. RESULT: No significant differences in gestational age at birth, initial medical severity, hours of intubation or other factors that could affect the outcome were observed across room type. Significantly more hours of visitation were observed in the first 2 weeks of life (P=0.02) and in weeks 3 and 4 (P=0.02) among infants in the SPR. More NICU stress was reported by mothers in the SPR after controlling for social support (P=0.04). CONCLUSION: Increased parent visitation is an important benefit of the SPR, however, mothers with infants in the SPR reported more stress.

DNA content measurement can be obtained using archival material for DNA flow cytometry. A comparison with cytogenetic analysis in 56 pediatric solid tumors.

BACKGROUND: Although flow cytometry (FCM) has become a widely used technique for the measurement of DNA content in solid tumors, the correlation of ploidy analysis by FCM with cytogenetic analysis (CGA) is not well described. The sensitivities of G-banded CGA and FCM were compared to determine the accuracy of the DNA index value (DI) as a measurement of chromosome number. METHODS: Tumor specimens from 56 pediatric cases were analyzed for DNA content by both FCM and CGA. Nuclei for FCM were prepared from archival tissue in 53 specimens using a modification of the Hedley technique and from fresh tissue in 3 specimens. Metaphase chromosomes for CGA were prepared from standard solid tumor harvests and Giemsa-trypsin banding procedures. Ploidy status for this study was defined as (1) diploid--DI between 0.97 and 1.03 by FCM or chromosome number +/- 2 from normal by CGA (44-48); and (2) aneuploid--DI < 0.97 or > 1.03 by FCM or total chromosomes < 44 or > 48 by CGA. RESULTS: Forty-nine of the 56 pediatric specimens were evaluable by both techniques. Concordance was observed in 34 cases (69%) between the two techniques in assigning similar ploidy status to a tumor (22 diploid and 12 aneuploid). It also was observed that among the aneuploid concordant cases, the actual DI obtained from archival material could predict total chromosome number with 95% accuracy. The 15 discordant cases showed a distinct aneuploid population by FCM, but were diploid by CGA. CONCLUSIONS: A correlation of 69% was obtained between both techniques to assign a similar ploidy status (diploid versus aneuploid) in 56 pediatric solid tumors. These results support the combined use of CGA and FCM to obtain the most complete analysis of DNA content and chromosome abnormalities in pediatric solid tumors. FCM on formalin-fixed, paraffin-embedded tissue can be used to measure total DNA content.

Visual and verbal short-term memory deficits in childhood leukemia survivors after intrathecal chemotherapy.

Assessed survivors of childhood lymphoblastic leukemia (ALL) treated with intrathecal chemotherapy, using the Wide Range Assessment of Memory and Learning (WRAML), compared to controls without cancer, matched as closely as possible in age, SES, and gender. Mild, but consistent, deficits were found in both visual-spatial and verbal single-trial memory tasks. In multitrial learning, only visual-spatial tasks resulted in deficient scores, while verbal learning was within the normal range. IQ results indicated scores 10-20 points lower in the ALL group. Memory results are related to deficits in strategic planning and attentional distractiveness. The WRAML may be a useful clinical tool to evaluate differential memory deficits in children with ALL.

Childhood Ki-1 lymphoma: presentation as a buttock mass.

Ki-1 lymphoma is a rare, large-cell anaplastic non-Hodgkin's lymphoma that most commonly affects older children and young adults. Presentation usually occurs as a localized infiltration of the skin and lymph nodes. We report an unusual case of childhood Ki-1 lymphoma that presented as a buttock mass in an eight-year-old girl, Pathologic evaluation revealed the characteristic lymphoma cells expressing Ki-1 antigen (CD-30), HLA-DR, interleukin 2 (CD-25), T-cell gene rearrangement, and the cytogenetic karyotype t(2;5). The patient is in complete remission following treatment with combination chemotherapy. This report broadens the clinical spectrum associated with Ki-1 lymphomas and illustrates the importance of combining routine pathologic examination with other specialized diagnostic techniques in the evaluation of childhood soft-tissue masses.

Survival of children and adolescents with acute lymphoid leukemia. A study of American Indians and Hispanic and non-Hispanic whites treated in New Mexico (1969 to 1986).

During the period 1969 to 1986, 196 American Indian and Hispanic and non-Hispanic white children and adolescents (ages, 0 to 19 years) were treated for acute lymphoid leukemia (ALL) at the University of New Mexico affiliated institutions. There were 28 American Indians (14%), 91 Hispanic whites (46%), and 77 non-Hispanic whites (39%). Median survivals for patients undergoing antileukemic therapy ranged from 8 months for American Indian boys to 140 months for non-Hispanic white girls. American Indian boys had the highest initial median leukocyte count (WBC) at 23.8 X 10(9)/l. Compliance problems occurred most commonly among American Indian children of both genders. Other clinical and pathologic features evaluated in this study were distributed similarly among the ethnic gender groups. Multi-variate analysis revealed that independent prognostic variables for survival included initial WBC, age, and gender. Ethnicity and compliance problems were possible, but confounded, prognostic variables. To the authors' knowledge this represents the most comprehensive study to date of ALL in American Indian patients.