PD 0332991, a selective cyclin D kinase 4/6 inhibitor, preferentially inhibits proliferation of luminal estrogen receptor-positive human breast cancer cell lines in vitro

Abstract Introduction Alterations in cell cycle regulators have been implicated in human malignancies including breast cancer. PD 0332991 is an orally active, highly selective inhibitor of the cyclin D kinases (CDK)4 and CDK6 with ability to block retinoblastoma (Rb) phosphorylation in the low nanomolar range. To identify predictors of response, we determined the in vitro sensitivity to PD 0332991 across a panel of molecularly characterized human breast cancer cell lines. Methods Forty-seven human breast cancer and immortalized cell lines representing the known molecular subgroups of breast cancer were treated with PD 0332991 to determine IC50 values. These data were analyzed against baseline gene expression data to identify genes associated with PD 0332991 response. Results Cell lines representing luminal estrogen receptor-positive (ER+) subtype (including those that are HER2 amplified) were most sensitive to growth inhibition by PD 0332991 while nonluminal/basal subtypes were most resistant. Analysis of variance identified 450 differentially expressed genes between sensitive and resistant cells. pRb and cyclin D1 were elevated and CDKN2A (p16) was decreased in the most sensitive lines. Cell cycle analysis showed G0/G1 arrest in sensitive cell lines and Western blot analysis demonstrated that Rb phosphorylation is blocked in sensitive lines but not resistant lines. PD 0332991 was synergistic with tamoxifen and trastuzumab in ER+ and HER2-amplified cell lines, respectively. PD 0332991 enhanced sensitivity to tamoxifen in cell lines with conditioned resistance to ER blockade. Conclusions These studies suggest a role for CDK4/6 inhibition in some breast cancers and identify criteria for patient selection in clinical studies of PD 0332991

Adult lymphoma-associated hemophagocytic lymphohistiocytosis: A clinical case series in a predominantly Hispanic cohort from the University of Miami/Jackson Memorial Hospital

e20060 Background: Hemophagocytic Lymphohistiocytosis (HLH) is a systemic inflammation disorder secondary to immune dysregulation. Patients may present with fevers, splenomegaly, bone marrow failure, and hemophagocytosis, among other clinical and laboratory findings. Lymphoma Associated HLH (LA-HLH) is a puzzling diagnosis given both conditions overlapping presentation. There are currently no established treatment guidelines for LA-HLH. Methods: We conducted a retrospective search of the tumor registry and pathology database at the University of Miami/Jackson Memorial Hospital to identify adult patients with the combined diagnosis of Lymphoma and HLH between January 2008 and July 2018. Results: Data from nine LA-HLH patients were identified and reviewed. Median age was 53 years (range 19-73), with 78% of cases of Hispanic origin. Lymphoma subtypes consisted of six T-cell/NK-cell neoplasms - 2 Peripheral T-cell Lymphomas (PTCL), NOS; 2 EBV+ Extranodal NK/T-Cell Lymphomas; 1 EBV+, CD8+, PTCL, NOS; 1 EBV+, Post-Transplant Lymphoproliferative Disorder-Anaplastic Large Cell Lymphoma, ALK negative (PTLD ALCL ALK-); and three B-cell neoplasms - 1 EBV+ DLBCL; 2 DLBCL, NOS. HLH and Lymphoma were diagnosed simultaneously in 6/9 cases. Hemophagocytosis phenomena was demonstrated in 7/9 cases. Treatment consisted of combined HLH and Lymphoma therapies in 4 cases, while Lymphoma directed therapy was applied to four patients; another case was treated with a modified version of the HLH-1994 protocol. Overall, a total of five cases were exposed to HLH-directed regimens (HLH-1994/2004). Three patients had refractory LA-HLH and entered hospice care, whereas another 3 cases succumbed to treatment-related complications. Of the seven cases that were evaluable for Lymphoma response, four cases (57%) achieved CR, and three of them (43%) were alive with no evidence of recurrence at 10, 16, and 52 months as of last contact. Conclusions: Herein, we describe our unique experience of an LA-HLH case series in a predominantly Hispanic population in South Florida. The diagnosis is challenging, often delayed, and the prognosis is dismal in refractory cases despite currently available rescue therapies. Furthermore, we describe for the first time the association between HLH and PTLD ALCL

The HSP90 inhibitor NVP-AUY922 potently inhibits non-small cell lung cancer growth

Heat shock protein 90 (HSP90) is involved in protein folding and functions as a chaperone for client proteins, many of which are important in non-small cell lung cancer (NSCLC) pathogenesis. We sought to define effects of the HSP90 inhibitor NVP-AUY922 in NSCLC cell lines, and identify predictors of response by in vitro and in vivo evaluation. NVP-AUY922 potently inhibited growth in all 41 NSCLC cell lines evaluated in vitro with IC50 < 100 nM. In 36 lines, IC100 (complete inhibition of proliferation) was below 40 nM. Greatest sensitivity was in lines with low baseline HSP70 protein levels. In vitro comparison of gene expression before and after NVP-AUY922 exposure demonstrated consistent changes in expression of genes involved in a wide range of cellular functions, including consistently decreased expression of dihydrofolate reductase after exposure. Expression of the co-chaperone AHA1 increased in response to exposure, and this effect was disproportionately seen in less sensitive lines. NVP-AUY922 slowed growth of A549 (KRAS mutant) xenografts, and achieved tumor stability and decreased epidermal growth factor receptor (EGFR) protein expression in H1975 xenografts, a model harboring a sensitizing and a resistance mutation for EGFR tyrosine kinase inhibitors in the EGFR gene. This impressive preclinical efficacy in a broad range of NSCLC cell lines led to clinical evaluation of NVP-AUY922 in NSCLC patients with tumors bearing known driver mutations as well as tumors without such abnormalities. An ongoing phase II NSCLC trial will incorporate correlative data to confirm our observations and guide further development of NVP-AUY922 in NSCLC. Word Count: 249 of (max 250

The HSP90 Inhibitor NVP-AUY922 Potently Inhibits Non–Small Cell Lung Cancer Growth

Heat shock protein 90 (HSP90) is involved in protein folding and functions as a chaperone for numerous client proteins, many of which are important in non-small cell lung cancer (NSCLC) pathogenesis. We sought to define preclinical effects of the HSP90 inhibitor NVP-AUY922 and identify predictors of response. We assessed in vitro effects of NVP-AUY922 on proliferation and protein expression in NSCLC cell lines. We evaluated gene expression changes induced by NVP-AUY922 exposure. Xenograft models were evaluated for tumor control and biological effects. NVP-AUY922 potently inhibited in vitro growth in all 41 NSCLC cell lines evaluated with IC(50) < 100 nM. IC(100) (complete inhibition of proliferation) < 40 nM was seen in 36 of 41 lines. Consistent gene expression changes after NVP-AUY922 exposure involved a wide range of cellular functions, including consistently decreased dihydrofolate reductase (DHFR) after exposure. NVP-AUY922 slowed growth of A549 (KRAS mutant) xenografts, and achieved tumor stability and decreased epidermal growth factor receptor (EGFR) protein expression in H1975 xenografts, a model harboring a sensitizing and a resistance mutation for EGFR tyrosine kinase inhibitors in the EGFR gene. This data will help inform the evaluation of correlative data from a recently completed phase II NSCLC trial and a planned phase IB trial of NVP-AUY922 in combination with pemetrexed in NSCLC

Short survival and frequent transformation in extranodal marginal zone lymphoma with multiple mucosal sites presentation

Between 11 and 37% of extranodal marginal zone lymphoma (EMZL) patients present with disease involvement in multiple mucosal sites (MMS). We analyzed 405 EMZL patients seen between 1995 and 2017: 265 (65.4%) patients presented with stage I disease, 49 of 309 (15.8%) patients with bone marrow involvement, and 35 of 328 (10.7%) patients with monoclonal gammopathy (MG). Forty-three (10.6%) patients had MMS presentation, which was more frequently seen in patients aged >60 years (55.8%). Five (17.9%) of 28 MMS patients had MG. MMS patients commonly exhibited the International Prognostic Index (IPI) >2 (79.1%), Follicular Lymphoma International Prognostic Index (FLIPI) >2 (39.5%), and Mucosa-Associated Lymphoid Tissue Lymphoma International Prognostic Index (MALT-IPI) 2-3 (60.5%). Both MMS presentation and MG were associated with shorter survival univariately. In multivariable Cox regression models, shorter progression-free survival (PFS) and overall survival (OS) were observed in patients with MMS (hazard ratio [HR] = 3.08 and 2.92, respectively), age ≥60 years (HR = 1.52 and 2.45, respectively), and in patients who failed to attain a complete remission following initial therapy (HR = 3.27 and 2.13, respectively). Elevated lactate dehydrogenase was associated with shorter PFS (HR = 1.92), while anemia (HR = 2.46) was associated with shortened OS. MALT-IPI ≥2 (HR = 2.47 and 4.75), FLIPI >2 (HR = 1.65 and 2.09), and IPI >2 (HR = 2.09 and 1.73) were associated with shorter PFS and OS, respectively. Higher grade transformation (HGT) occurred in 11 (25.6%) MMS patients with a 5-year cumulative incidence of 13.2% (95% CI 4.7-26.1%). EMZL patients with MMS presentation represent a novel clinical subset associated with shorter PFS, OS, and higher incidence of HGT that needs novel therapeutic approaches