Casey Williams

Targeting levels or oligomerization of nucleophosmin 1 induces differentiation and loss of survival of human AML cells with mutant NPM1

Nucleophosmin 1 (NPM1) is an oligomeric, nucleolar phosphoprotein that functions as a molecular chaperone for both proteins and nucleic acids. NPM1 is mutated in approximately one-third of patients with AML. The mutant NPM1c+ contains a 4-base insert that results in extra C-terminal residues encoding a nuclear export signal, which causes NPM1c+ to be localized in the cytoplasm. Here, we determined the effects of targeting NPM1 in cultured and primary AML cells. Treatment with siRNA to NPM1 induced p53 and p21, decreased the percentage of cells in S-phase of the cell cycle, as well as induced differentiation of the AML OCI-AML3 cells that express both NPMc+ and unmutated NPM1. Notably, knockdown of NPM1 by shRNA abolished lethal AML phenotype induced by OCI-AML3 cells in NOD/SCID mice. Knockdown of NPM1 also sensitized OCI-AML3 to all-trans retinoic acid (ATRA) and cytarabine. Inhibition of NPM1 oligomerization by NSC348884 induced apoptosis and sensitized OCI-AML3 and primary AML cells expressing NPM1c+ to ATRA. This effect was significantly less in AML cells coexpressing FLT3-ITD, or in AML or normal CD34+ progenitor cells expressing wild-type NPM1. Thus, attenuating levels or oligomerization of NPM1 selectively induces apoptosis and sensitizes NPM1c+ expressing AML cells to treatment with ATRA and cytarabine.

Treatment-, patient-, and disease-related factors and the emergence of adverse events with tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia.

Four breakpoint cluster region (BCR)‐ABL1 tyrosine kinase inhibitors (TKIs) are currently available for the treatment of chronic myeloid leukemia (CML): imatinib, nilotinib, dasatinib, and bosutinib. Choosing the most appropriate TKI requires clinicians to consider a host of patient‐, disease‐, and treatment‐related factors, not the least of which include the safety profiles of the agents. This review discusses the potential impact of treatment‐, patient‐, and disease‐related characteristics on the emergence of adverse events during TKI therapy, with a focus on the underlying mechanisms believed to be responsible for a number of important adverse events associated with these agents and what implications they may have for treatment choice, particularly in the setting of first‐line treatment. A literature search of the PubMed database was conducted to identify articles that described the molecular mechanisms of BCR‐ABL1–mediated leukemic transformation, the efficacy and safety of imatinib, nilotinib, dasatinib, and bosutinib in patients with CML, the kinase‐binding spectrum of each TKI, and evidence suggesting a link between the TKI‐binding profile and adverse events. The pattern of adverse events associated with each agent is important when selecting treatment with a TKI. Clinical studies suggest that imatinib, nilotinib, dasatinib, and bosutinib have differing safety profiles, which are in part attributable to the specificity and selectivity of each agent. Although much basic research must be conducted to further illuminate the mechanisms responsible for TKI‐related adverse events, on‐ and off‐target effects are believed to be at least partly responsible for cardiovascular toxicity, myelosuppression, fluid retention, gastrointestinal toxicity, and dermatologic toxicity. Increased understanding of the factors that affect TKI‐associated adverse events and long‐term safety data will enable a more informed approach to the selection of therapy best suited to the individual needs of patients with CML.

Serum proteomic profiling and haptoglobin polymorphisms in patients with GVHD after allogeneic hematopoietic cell transplantation

We studied serum proteomic profiling in patients with graft versus host disease (GVHD) after allogeneic hematopoietic cell transplantation (allo-HCT) by two-dimensional gel electrophoresis (2-DE) and mass spectrometry analysis. The expression of a group of proteins, haptoglobin (Hp), alpha-1-antitrypsin, apolipoprotein A-IV, serum paraoxonase and Zn-alpha-glycoprotein were increased and the proteins, clusterin precursor, alpha-2-macroglobulin, serum amyloid protein precursor, sex hormone-binding globulin, serotransferrin and complement C4 were decreased in patients with extensive chronic GVHD (cGVHD). Serum haptoglobin (Hp) levels in patients with cGVHD were demonstrated to be statistically higher than in patients without cGVHD and normal controls (p < 0.01). We used immunoblotting and PCR in combination with 2-DE gel image analysis to determine Hp polymorphisms in 25 allo-HCT patients and 16 normal donors. The results demonstrate that patients with cGVHD had a higher incidence of HP 2-2 phenotype (43.8%), in comparison to the patients without cGVHD (0%) and normal donors (18.7%), suggesting the possibility that specific Hp polymorphism may play a role in the development of cGVHD after allo-HCT. In this study, quantitative serum Hp levels were shown to be related to cGVHD development. Further, the data suggest the possibility that specific Hp polymorphisms may be associated with cGVHD development and warrant further investigation.

Utility of Genomic Analysis In Circulating Tumor DNA from Patients with Carcinoma of Unknown Primary

Carcinoma of unknown primary (CUP) is a rare and difficult-to-treat malignancy, the management of which might be improved by the identification of actionable driver mutations. We interrogated 54 to 70 genes in 442 patients with CUP using targeted clinical-grade, next-generation sequencing of circulating tumor DNA (ctDNA). Overall, 80% of patients exhibited ctDNA alterations; 66% (290/442) ≥1 characterized alteration(s), excluding variants of unknown significance. TP53-associated genes were most commonly altered [37.8% (167/442)], followed by genes involved in the MAPK pathway [31.2% (138/442)], PI3K signaling [18.1% (80/442)], and the cell-cycle machinery [10.4% (46/442)]. Among 290 patients harboring characterized alterations, distinct genomic profiles were observed in 87.9% (255/290) of CUP cases, with 99.7% (289/290) exhibiting potentially targetable alterations. An illustrative patient with dynamic changes in ctDNA content during therapy and a responder given a checkpoint inhibitor-based regimen because of a mismatch repair gene anomaly are presented. Our results demonstrate that ctDNA evaluation is feasible in CUP and that most patients harbor a unique somatic profile with pharmacologically actionable alterations, justifying the inclusion of noninvasive liquid biopsies in next-generation clinical trials. Cancer Res; 77(16); 4238-46. ©2017 AACR.

Effectiveness of Exogenous Albumin Administration for the Prevention of Ifosfamide-Induced Encephalopathy

Study Objectives. To assess the effectiveness of prophylactic albumin for the prevention of ifosfamide‐induced encephalopathy (IIE), and to describe risk factors for IIE and investigate the predictive potential of a novel risk‐stratification model for IIE.

Initial therapy in multiple myeloma: investigating the new treatment paradigm

The development of three novel chemotherapeutic agents — thalidomide, lenalidomide, and bortezomib — has resulted in a fundamental shift in the management of multiple myeloma. Despite this tremendous advancement, the selection of initial treatment must still be made with a degree of uncertainty as a true standard therapy has yet to be established. Although challenging, the relative abundance of therapeutic options, when taken into consideration with unique patient characteristics, creates the potential for individualization of care. For patients eligible for autologous stem cell transplantation, various combinations of novel agents with dexamethasone or traditional chemotherapy have supplanted the previous standard regimen consisting of vincristine, doxorubicin, and dexamethasone. In elderly patients or others that are deemed ineligible for the transplant procedure, the addition of a novel agent to melphalan-prednisone has demonstrated significant improvements in response rates. Due to the immaturity of the available data, it is perhaps best to regard the era of novel agents with a degree of rational enthusiasm, as the ultimate impact on patient care remains undetermined. Although further research is clearly implicated, recent advancements have resulted in significant progress toward obtaining optimum outcomes in a historically challenging disease.

Identifying biomarkers to select patients with early breast cancer suitable for extended adjuvant endocrine therapy.

Purpose of review In this review, we summarize recent and current biomarkers and assays that are being considered in the selection of suitable patients with estrogen receptor-positive early breast cancer for extended (years 5–10) adjuvant endocrine therapy (AET). Recent findings Women with estrogen receptor-positive early-stage breast cancer (65% of cases) continue to have late risk for distant recurrence extending beyond 5 years from surgery. Recent large trials have consistently demonstrated improvement for prolonging endocrine therapy. However, endocrine therapy can cause women bothersome side effects and can negatively impact quality of life. Determining which patients remain at risk for disease recurrence and predicting which of these patients would derive the most benefit from the addition of extended AET are key issues faced by patients and oncologists today. A number of predictive molecular assays have been developed and are being considered as tools to be used in guiding the implementation of adjuvant systemic therapy. Summary The future holds much promise and as more information and understanding is acquired, treatment regimens will increasingly incorporate clinically validated biomarker assays in the decision-making process that will be of great benefit to these patients. Proving clinical utility, though, will ultimately decide their implementation.

Dual Blockade of HER-2 Provides a Greater Magnitude of Benefit in Patients With Hormone-Negative Versus Hormone-Positive Breast Cancer

The dual small molecule tyrosine kinase inhibitor lapatinib blocks both human epidermal growth factor receptor (HER-1) and human epidermal growth factor receptor 2 (HER-2) tyrosine kinase activity by binding reversibly to the ATP-binding site of the receptors intracellular domain. Lapatinib, in combination with capecitabine, has been approved in 2007 for the treatment of patients with advanced HER-2+ breast cancer upon progressive disease following standard chemotherapy. Approval was also extended to the treatment of postmenopausal women with advanced hormone receptor (HR)-positive and HER-2-positive breast cancer in 2010. More recently, clinical trials that have investigated the efficacy of dual HER-2 blockade in both the metastatic and neoadjuvant breast cancer settings. For example, in 2013 the European Medicines Agency approved the combination of lapatinib and trastuzumab in HER-2+/HR- patients. We review the efficacy results from dual HER-2 blockade studies and present new post hoc analysis efficacy data according to HR status. We show that dual blockade of HER-2 appears to provide a greater magnitude of benefit in the HR- versus the HR+ subgroup of patients. Finally, we examine the potential of molecularly subtyping HER-2+ tumors using the PAM50 test as a predictor of response to treatment with the combination of trastuzumab and lapatinib.

Utilizing Tumor and Plasma Liquid Biopsy in Treatment Decision Making for an Estrogen Receptor-Positive Advanced Breast Cancer Patient

Breast cancer affects 12% of females in the United States and is the leading cause of cancer death in the female population. Personalized therapy is being used in clinical practice to treat breast cancer based on tumor molecular profiling, which can be obtained from tissue biopsy or plasma liquid biopsy as circulating tumor deoxyribonucleic acid (ctDNA). The available ctDNA tests provide a non-invasive way to monitor the cancer genome in a real-time manner. In this case report, a 38-year-old female with recurrent estrogen receptor (ER) positive breast cancer is treated with letrozole, everolimus, and palbociclib. The drugs target the hormonal signaling pathway, phosphoinositide 3-kinase (PI3K)-RAC-alpha serine/threonine-protein kinase (AKT) pathway, and cyclin D1 (CCND1)-CDK4/6 pathway, based on the patient’s estrogen-receptor-positive (ER+) disease and phosphatidylinositol -4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation, as well as PIK3CA and CCND1 amplification. After 11 months of treatment, retinoblastoma protein transcriptional corepressor 1 (RB1) mutation was caught in ctDNA, which suggests an acquired resistance to palbociclib. Pazopanib was then used instead of palbociclib, targeting the fibroblast growth factor 3/4/19 (FGF3/4/19) amplification that was initially observed in her molecular profiling. Trametinib was also suggested recently due to the increasing allele frequency of B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutation in ctDNA, following the treatment of letrozole + everolimus + pazopanib. The patient has no evidence of disease after five months of treatment initiation and has remained disease-free for over 16 months. In conclusion, the analysis of ctDNA is an effective way to monitor the real-time changes in a patients tumor genome, which is a great supplement to the molecular profile from the tissue biopsy. The combination of these two tests provides an efficient strategy to make more informed treatment decisions, which greatly adapt along disease development.

Metastatic Triple Negative Breast Cancer patient with TP53 tumor mutation experienced 11 months progression-free survival on bortezomib monotherapy without adverse events after ending standard treatments with grade 3 adverse events

A triple-negative breast cancer patient had no hereditary BRCA1, BRCA2, or TP53 risk variants. After exhaustion of standard treatments, she underwent experimental treatments and whole-exome sequencing of tumor, blood, and a metastasis. Well-tolerated experimental bortezomib monotherapy was administered for a progression-free period of 11 mo. After progression, treatments were changed and the exome data were evaluated, expanded with RNA and exome sequencing of a late-stage metastasis. In the final stage, eribulin alone and in combination with anthracyclines were administered. While suffering from grade 3 adverse events, skin metastases progressed. She lived 51 mo after initial diagnosis. Toxicity from anthracyclines and cisplatin may have been due to associated germline variants CBR3 C4Y and V224M and GSTP1 I105V, respectively. Somatic mutations predicted or reported as pathogenic were detected in 38 genes in tumor tissues. All tumor samples harbored the heterozygous TP53 Y220C variant, known to destabilize p53 and down-regulate p53-mediated apoptosis. The success of bortezomib may be explained by the previously reported up-regulation of caspase-mediated apoptosis, which is p53-independent. Phylogenetic analysis of blood, primary tumor, and two metastases inferred an ancestral tumor cell with 12 expressed tumor mutations from which all three tumors may have evolved. Although our first urgent analysis could only include 40 genes, postmortem analysis uncovered the aggressiveness and suggested experimental therapies including 16 actionable targets, partly validated by immunohistochemistry. Exome and transcriptome analyses yielded comprehensive therapy-relevant information and should be considered for patients at first diagnosis.