Inhibition of Syk protein tyrosine kinase induces apoptosis and blocks proliferation in T-cell non-Hodgkin's lymphoma cell lines

Abstract Risk-adapted therapy has resulted in a improvement of outcome in childhood acute lymphoblastic leukemia (ALL), however, T-cell ALL (T-ALL) have still relatively poor outcome compared to B-precursor ALL. Although activating mutations of the NOTCH1 gene have been reported in more than half of T-ALL, the prognostic significance of this finding has yet to be determined. CDC4 gene was isolated as a negative regulator of NOTCH1 and mutations were detected in T-ALL cell line and other cancers. We performed mutation analysis of the NOTCH1 and CDC4 gene in 14 T-ALL cell lines, 52 T-ALL and 17 T cell non-Hodgkin’s lymphoma (T-NHL) fresh samples. All children with T-ALL and T-NHL were treated on Japan Association of Childhood Leukemia Study (JACLS) ALL-97 and NHL-98 protocol after obtaining informed consent. Mutation detection was performed via PCR based denaturing HPLC followed by direct sequence.Mutations of the NOTCH1 were identified in 10 (71.4%) of 14 T-ALL cell lines, 16 (30.8%) of 52 T-ALL and 6 (35.3%) of 17 T-NHL fresh samples. Twelve mutations in heterodimerization domain (HD) and 12 mutations in PEST domain (PD) were found in 69 fresh samples. The incidence of the NOTCH1 mutation is less frequent than that of previous reports. We found CDC4 mutations in 12 (35.3%) of 52 T-ALL and 2 (11.8%) of 17 T-NHL fresh samples. One insertion mutation in exon 3 and 11 missense mutations were detected in CDC4 gene. Both NOTCH1 and CDC4 mutations were found in 7 patients. Interestingly, the NOTCH1 mutations were only observed in T-ALL and T-NHL patients without relapse, suggesting to be associated with favorable prognosis. However, CDC4 gene was found not to be associated with prognosis.

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p53 Mutations, c-myc and bcl-2 Rearrangements in Human Non-Hodgkin's Lymphoma Cell Lines

Leukemia & Lymphoma ◽

10.3109/10428199509059672 ◽

1995 ◽

Vol 19 (1-2) ◽

pp. 165-171 ◽

Cited By ~ 26

Author(s):

Hong Chang ◽

John A. Blondal ◽

Sam Benchimol ◽

Mark D. Minden ◽

Hans A. Messner

Keyword(s):

Cell Lines ◽

Hodgkin’S Lymphoma ◽

Lymphoma Cell ◽

Hodgkin's Lymphoma ◽

P53 Mutations ◽

Non Hodgkin’S Lymphoma ◽

Non Hodgkin's Lymphoma

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Identification of MicroRNA Markers of Sensitivity to the Novel Bruton’s Tyrosine Kinase (BTK) Inhibitor PCI-32765 in Non-Hodgkin’s Lymphoma.

Blood ◽

10.1182/blood.v112.11.3366.3366 ◽

2008 ◽

Vol 112 (11) ◽

pp. 3366-3366 ◽

Cited By ~ 1

Author(s):

Sriram Balasubramanian ◽

Jun Chen ◽

Lee Honigberg ◽

Lillian Tee ◽

Hannah Mamuszka

Keyword(s):

Tyrosine Kinase ◽

B Cell ◽

Cell Lines ◽

Hodgkin’S Lymphoma ◽

Human Tumors ◽

Hodgkin's Lymphoma ◽

Bruton’S Tyrosine Kinase ◽

Bruton's Tyrosine Kinase ◽

Non Hodgkin’S Lymphoma ◽

Non Hodgkin's Lymphoma

Abstract PCI-32765 is a novel, first-in-class small molecule inhibitor of Bruton’s tyrosine kinase (BTK), currently in preclinical development and shortly entering Phase I clinical trials for the treatment of hematological malignancies. BTK is essential in B-cells for signalling via the B-cell receptor (BCR), and mutations in BTK have been shown to cause x-linked agammaglobulinemia in humans and x-linked immunodeficiency (xid) in mice. We have found that PCI-32765 has demostrated significant growth inhibitory activity in vitro in a number of non-Hodgkin’s lymphoma (NHL) cell lines as well as primary human NHL tumors cultivated ex-vivo. However, certain subsets of NHL cell lines were found to respond better to the inhibitor, and in keeping with this, a wide variance was also observed in the response among primary human tumors. PCI-32765 had GI50 <3uM in 7/15 cell lines (46%), including 3 follicular lymphoma (FL) and 3 diffuse large B-cell lymphoma (DLBCL) lines. Based on these results, we tested primary tumors including 15 FL and 7 DLBCL, utilizing a modified version of Oncotech’s EDR Assay. We found that while only 1 of the DLBCL tumors showed a similar response, PCI-32765 had a response rate of 40% in the primary FL samples. The reasons for this variation are still under investigation but one reason may be that that not all tumors are equally dependent on BTK activation for their survival. In order to obtain a predictive marker for response to PCI-32765 in human tumors, we utilized a microRNA (miRNA) profiling approach in the primary FL tumors using a commercially available miRNA array platform. We hypothesized that miRNA might be a better diagnostic tool than mRNA because miRNA function is more conserved and it is more stable than mRNA (thus easier to harvest successfully from paraffin embedded blocks). Further, it has been shown that miRNA signatures can predict responsive and resistant phenotypes based on basal miRNA levels, and have been found to have essential functions in lymphomas. When the miRNA profiles from the FL tumors were analyzed, we found that a signature consisting of 4 miRNAs could predict the sensitive tumors with a p-value <0.01. Of these, 2 were upregulated and 2 were downregulated in the sensitive samples compared to the resistant ones. It is likely therefore that these are implicated in the mechansisms of sensitivity and resistance to PCI-32765 in the FL tumors, and the connections between genes regulated by these miRNAs to pathways controlled by BTK are being explored.

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