NFkB is activated by multiple mechanisms in hairy cell leukemia

Hairy cell leukemia 2024: Update on diagnosis, risk-stratification, and treatment-Annual updates in hematological malignancies

DISEASE OVERVIEW

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogenous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment.

DIAGNOSIS

Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11c, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral bone marrow infiltration and the presence of BRAFV600E somatic mutation.

RISK STRATIFICATION

Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34 positive HCL cases are associated with a poor prognosis, as well as HCL with TP53 mutations and HCL-V.

TREATMENT

Patients should be treated only if HCL is symptomatic. Chemotherapy with risk-adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining cladribine (CDA) and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus R, MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22, Bruton tyrosine kinase inhibitors (BTKi), and Bcl-2 inhibitors (Bcl-2i). However, the optimal sequence of the different treatments remains to be determined.

Deciphering Genetic Alterations of Hairy Cell Leukemia and Hairy Cell Leukemia-like Disorders in 98 Patients

Simple Summary

The diagnosis of hairy cell leukemia (cHCL) and HCL-like disorders, including the variant form of HCL (vHCL) and splenic diffuse red pulp lymphoma (SDRPL) can be challenging, particularly in complex situations. The integration of all data, including molecular data, is essential for distinguishing the different entities. The BRAF^V600E mutation is identified in most cHCL cases, whereas it is absent in vHCL and SDRPL. MAP2K1 mutations are observed in half of vHCL cases and in cHCL BRAF^WT and they are associated with a worse prognosis. The interest in deep sequencing for the diagnosis and prognosis of hairy cell leukemia and HCL-like disorders is essential. Some KLF2 genetic alterations have been localized on the AID consensus motif, suggesting an AID-induced mutation mechanism. KLF2 is the second most altered gene in HCL, and mutations must be investigated to confirm whether AID could be responsible for the genetic alterations in this gene. Clonal evolution can be observed in half of the cases.

Abstract

Hairy cell leukemia (cHCL) patients have, in most cases, a specific clinical and biological presentation with splenomegaly, anemia, leukopenia, neutropenia, monocytopenia and/or thrombocytopenia, identification of hairy cells that express CD103, CD123, CD25, CD11c and identification of the V600E mutation in the B-Raf proto-oncogene (BRAF) in 90% of cases. Monocytopenia is absent in vHCL and SDRPL patients and the abnormal cells do not express CD25 or CD123 and do not present the BRAF^V600E mutation. Ten percent of cHCL patients are BRAF^WT and the distinction between cHCL and HCL-like disorders including the variant form of HCL (vHCL) and splenic diffuse red pulp lymphoma (SDRPL) can be challenging. We performed deep sequencing in a large cohort of 84 cHCL and 16 HCL-like disorders to improve insights into the pathogenesis of the diseases. BRAF mutations were detected in 76/82 patients of cHCL (93%) and additional mutations were identified in Krüppel-like Factor 2 (KLF2) in 19 patients (23%) or CDKN1B in 6 patients (7.5%). Some KLF2 genetic alterations were localized on the cytidine deaminase (AID) consensus motif, suggesting AID-induced mutations. When analyzing sequential samples, a clonal evolution was identified in half of the cHCL patients (6/12 pts). Among the 16 patients with HCL-like disorders, we observed an enrichment of MAP2K1 mutations in vHCL/SDRPL (3/5 pts) and genes involved in the epigenetic regulation (KDM6A, EZH2, CREBBP, ARID1A) (3/5 pts). Furthermore, MAP2K1 mutations were associated with a bad prognosis and a shorter time to next treatment (TTNT) and progression-free survival (PFS), independently of the HCL classification.

Transforming Growth Factor-Beta (TGF-β) Signaling in Cancer-A Betrayal Within

A ubiquitously expressed cytokine, transforming growth factor-beta (TGF-β) plays a significant role in various ongoing cellular mechanisms. The gain or loss-of-function of TGF-β and its downstream mediators could lead to a plethora of diseases includes tumorigenesis. Specifically, at the early onset of malignancy TGF-β act as tumour suppressor and plays a key role in clearing malignant cells by reducing the cellular proliferation and differentiation thus triggers the process of apoptosis. Subsequently, TGF-β at an advanced stage of malignancy promotes tumorigenesis by augmenting cellular transformation, epithelial-mesenchymal-transition invasion, and metastasis. Besides playing the dual roles, depending upon the stage of malignancy, TGF-β also regulates cell fate through immune and stroma components. This oscillatory role of TGF-β to fight against cancer or act as a traitor to collaborate and crosstalk with other tumorigenic signaling pathways and its betrayal within the cell depends upon the cellular context. Therefore, the current review highlights and understands the dual role of TGF-β under different cellular conditions and its crosstalk with other signaling pathways in modulating cell fate.

High expression level of ROR1 and ROR1-signaling associates with venetoclax resistance in chronic lymphocytic leukemia

Although the BH3-mimetic venetoclax is highly cytotoxic for chronic lymphocytic leukemia (CLL) cells, some patients with CLL fail to clear minimal residual disease (MRD). We examined the CLL cells of seven such patients (CLL1-7) and found each had high-level expression of ROR1. By examining the CLL cells from such patients prior to therapy at SC1 and then more than 1 year later (Sample Collection 2 (SC2)), when they had progressive increases in MRD despite continued venetoclax therapy, we found the levels of ROR1 expressed on CLL cells at SC2 were significantly higher than that on CLL cells collected at SC1. At SC2, we also observed upregulation of genes induced by Wnt5a-induced ROR1 signaling, including BCL2L1. Transduction of the CLL-cell-line MEC1 to express ROR1 enhanced expression of target genes induced by ROR1-signaling, increased expression of BCL-XL, and enhanced resistance to venetoclax, even in MEC1 made to express mutant forms of BCL2, which are associated with venetoclax resistance. Treatment of primary CLL cells with Wnt5a also increased their resistance to venetoclax, an effect that could be inhibited by the anti-ROR1 mAb (UC-961, zilovertamab). Collectively, these studies indicate that Wnt5a-induced ROR1-signaling can enhance resistance to venetoclax therapy.

Involvement of classic and alternative non-homologous end joining pathways in hematologic malignancies: targeting strategies for treatment

Chromosomal translocations are the main etiological factor of hematologic malignancies. These translocations are generally the consequence of aberrant DNA double-strand break (DSB) repair. DSBs arise either exogenously or endogenously in cells and are repaired by major pathways, including non-homologous end-joining (NHEJ), homologous recombination (HR), and other minor pathways such as alternative end-joining (A-EJ). Therefore, defective NHEJ, HR, or A-EJ pathways force hematopoietic cells toward tumorigenesis. As some components of these repair pathways are overactivated in various tumor entities, targeting these pathways in cancer cells can sensitize them, especially resistant clones, to radiation or chemotherapy agents. However, targeted therapy-based studies are currently underway in this area, and furtherly there are some biological pitfalls, clinical issues, and limitations related to these targeted therapies, which need to be considered. This review aimed to investigate the alteration of DNA repair elements of C-NHEJ and A-EJ in hematologic malignancies and evaluate the potential targeted therapies against these pathways.

Apigenin Exerts Anti-inflammatory Effects in an Experimental Model of Acute Pancreatitis by Down-regulating TNF-α

BACKGROUND/AIM

This study investigated the anti-inflammatory effect of apigenin in an experimental model of acute pancreatitis. Inflammatory response was reflected by tissue expression of the cytokine TNF-α coupled with histological examination.

MATERIALS AND METHODS

Wistar rats were divided into three groups: Sham-group animals underwent laparotomy only, without any other interventions. Control-group animals underwent laparotomy and bilio-pancreatic duct ligation to induce pancreatitis without apigenin administration. Apigenin group animals were further treated with apigenin. Euthanasia was performed at 6, 12, 24, 48 and 72 h post-operatively.

RESULTS

Over-expression of TNF-α in relation to postoperative time was observed in the control group (p<0.001). In the apigenin group, under-expression of TNF-α in relation to postoperative time was observed (p<0.013). At 72 h, apigenin reduced pancreatic TNF-α expression and prevented pancreatic necrosis.

CONCLUSION

Apigenin slows progression and reduces severity of acute pancreatitis. Apigenin may serve as an adjunct to a more successful therapeutic strategy in acute pancreatitis.

The effect of acai (Euterpe oleracea Mart.) intake on the atherosclerosis inflammatory mediators (sCD40L e CCL5) in apparently healthy women

Purpose

The purpose of this paper is to investigate the effects of acai pulp consumption on biometric parameters and inflammatory biomarkers (sCD40L, CCL5, TNF-a and CRP) in apparently healthy women.

Design/methodology/approach

Nutritional intervention was performed with women who consumed 200 g of acai pulp daily during 30 consecutive days. Firstly, they were divided into two groups: normal weight and overweight related to BMI. Then, such volunteers were subdivided into other two groups according to values below or above the median of sCD40L.

Findings

sCD40L (ρg/mL) concentrations increased in overweight volunteers post-consumption of acai (964 ± 542) compared with the same volunteers pre-consumption of acai (633 ± 187, p = 0.03), and the CCL5 concentrations (ρg/mL) decreased in volunteers with sCD40L concentrations below median after the treatment (4.1 ± 1.5) when compared in same volunteers before the treatment (5.8 ± 1.8, p = 0.02). Protein consumption (g) reduced in volunteers with sCD40L concentrations below median after the intervention (96.6 ± 44.5), when compared before the intervention (96.7 ± 33.8, p = 0.03).

Originality/value

This paper concluded that the acai consumption can modulate the inflammatory profile in both stratified volunteers according to the BMI and the sCD40L marker median.

Deciphering the genotype and phenotype of hairy cell leukemia: clues for diagnosis and treatment

Introduction: Hairy cell leukemia (HCL) is a rare, indolent B-cell neoplasm. The classical variant of the disease is characterized by the BRAF V600E mutation, which is present in virtually all cases. How this mutation leads to the signs and symptoms of the disease is currently not known. Areas covered: This review explores the genetic background of HCL, especially the BRAF V600E driver mutation, but passenger mutations and their effects are also included. The clinical significance of BRAF mutations in other cancer types is discussed, as well as BRAF- induced senescence. An overview of the major forms of treatment of HCL (cytostatic drugs, specific BRAF inhibitors, B cell-specific antibodies) is given. Finally, possible mechanisms of the monocytopenia and hairy morphology so typical of this disease are discussed. Expert opinion: Although being a rare disease, HCL and its pathogenesis can yield important information about BRAF-related cancer metabolism. Many aspects of the disease are still unclear, but with the right resources, this could change. This can lead to a more efficient and specific treatment, thus leading to decreased morbidity.

Suppression of Tescalcin inhibits growth and metastasis in renal cell carcinoma via downregulating NHE1 and NF-kB signaling

BACKGROUND

Renal cell carcinoma (RCC) is the most common form of kidney cancer. Recent studies reported that Tescalcin was overexpressed in various tumor types. However, the status of Tescalcin protein expression in RCC and its biological function is uncertain. This study was designed to investigate the expression of Tescalcin in human RCC and its biological function.

METHODS

shRNA transfection was performed to abrogates the expression of Tescalcin. Quantitative real time PCR and western blotting assays were used to determine mRNA and protein expression levels, respectively. The cell viability was analyzed by MTT and colony formation. Cell flow cytometry was used to assess pHi value and cell apoptosis. Cell invasive and migratory ability was measured with modified Boyden chamber assay. Xenograft model was setup to evaluate tumor growth.

RESULTS

Tescalcin was overexpressed in RCC tissues compared with matched normal tissues. It was also overexpressed in RCC cell lines relative that of normal cells. Suppression Tescalcin with specific shRNA resulted in the inhibition of cell proliferation, migration, invasion and apoptosis of RCC cells. Additionally, silencing of Tescalcin also caused the inhibition of the tumor growth in nude mice. Mechanistic study showed that Tescalcin regulated cell proliferation, migration and invasion via NHE1/pHi axis as well as AKT/NF-κB signaling pathway.

CONCLUSIONS

These findings demonstrate that atopic expression of Tescalcin facilitates the survival, migration and invasion of RCC cells via NHE1/pHi axis as well as AKT/ NF-κB signaling pathway, providing new perspectives for the future study of Tescalcin as a therapeutic target for RCC.

Immunhistochemical analysis of Nuclear Factor Kappa Beta expression in etiopathogenesis of ovarian tumors1

PURPOSE

To investigate the place of the transcription factor nuclear kappa B (NF-kB), which is a marker of chronic inflammation, in the etiology of the ovarian carcinoma.

METHODS

NFkB analysis with the immunohistochemical method has been performed. To evaluate immunohistochemical NF-kB expression in the ovarian tissue, the H-score method. H-score = ∑ Pi (i+1), where ''Pi'' is the percentage of stained cells in each intensity category (0-100%) and ''i'' is the intensity indicating weak (i=1), moderate (i=2) or strong staining (i=3).

RESULTS

It has been seen that, the mean H score is statistically significantly higher in the patient group with serous and musinous adenocarcinoma diagnosis than the two other patient groups (p<0.005).

CONCLUSIONS

Factor nuclear kappa B is an important mediator that acts in the chronic inflammation. The highest expression rates are determined by the immunohistochemical method in the ovarian cancer group.

New generation sequencing of targeted genes in the classical and the variant form of hairy cell leukemia highlights mutations in epigenetic regulation genes

Classical hairy cell leukemia (HCL-c) is a rare lymphoid neoplasm. BRAF^V600E mutation, detected in more than 80% of the cases, is described as a driver mutation, but additional genetic abnormalities appear to be necessary for the disease progression. For cases of HCL-c harboring a wild-type BRAF gene, the differential diagnosis of the variant form of HCL (HCL-v) or splenic diffuse red pulp lymphoma (SDRPL) is complex. We selected a panel of 21 relevant genes based on a literature review of whole exome sequencing studies (BRAF, MAP2K1, DUSP2, MAPK15, ARID1A, ARID1B, EZH2, KDM6A, CREBBP, TP53, CDKN1B, XPO1, KLF2, CXCR4, NOTH1, NOTCH2, MYD88, ANXA1, U2AF1, BCOR, and ABCA8). We analyzed 20 HCL-c and 4 HCL-v patients. The analysis of diagnostic samples mutations in BRAF (n = 18), KLF2 (n = 4), MAP2K1 (n = 3), KDM6A (n = 2), CDKN1B (n = 2), ARID1A (n = 2), CREBBP (n = 2) NOTCH1 (n = 1) and ARID1B (n = 1). BRAF^V600E was found in 90% (18/20) of HCL-c patients. In HCL-c patients with BRAF^V600E, other mutations were found in 33% (6/18) of cases. All 4 HCL-v patients had mutations in epigenetic regulatory genes: KDM6A (n = 2), CREBBP (n = 1) or ARID1A (n = 1). The analysis of sequential samples (at diagnosis and relapse) from 5 patients (2 HCL-c and 3 HCL-v), showed the presence of 2 new subclonal mutations (BCOR^E1430X and XPO1^E571K) in one patient and variations of the mutated allele frequency in 2 other cases. In the HCL-v disease, we described new mutations targeting KDM6A that encode a lysine demethylase protein. This opens new perspectives for personalized medicine for this group of patients.

Analysis of the interplay between all-trans retinoic acid and histone deacetylase inhibitors in leukemic cells

The treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) induces granulocytic differentiation. This process renders APL cells resistant to cytotoxic chemotherapies. Epigenetic regulators of the histone deacetylases (HDACs) family, which comprise four classes (I-IV), critically control the development and progression of APL. We set out to clarify the parameters that determine the interaction between ATRA and histone deacetylase inhibitors (HDACi). Our assays included drugs against class I HDACs (MS-275, VPA, and FK228), pan-HDACi (LBH589, SAHA), and the novel HDAC6-selective compound Marbostat-100. We demonstrate that ATRA protects APL cells from cytotoxic effects of SAHA, MS-275, and Marbostat-100. However, LBH589 and FK228, which have a superior substrate-inhibitor dissociation constant (Ki) for the class I deacetylases HDAC1, 2, 3, are resistant against ATRA-dependent cytoprotective effects. We further show that HDACi evoke DNA damage, measured as induction of phosphorylated histone H2AX and by the comet assay. The ability of ATRA to protect APL cells from the induction of p-H2AX by HDACi is a readout for the cytoprotective effects of ATRA. Moreover, ATRA increases the fraction of cells in the G1 phase, together with an accumulation of the cyclin-dependent kinase inhibitor p21 and a reduced expression of thymidylate synthase (TdS). In contrast, the ATRA-dependent activation of the transcription factors STAT1, NF-κB, and C/EBP hardly influences the responses of APL cells to HDACi. We conclude that the affinity of HDACi for class I HDACs determines whether such drugs can kill naïve and maturated APL cells.

[In vitro investigation on the mechanism of cyclooxygenase-2 upregulation induced by spleen tyrosine kinase-nuclear factor κB signaling in cancer pain caused by oral cancer-associated macrophage]

OBJECTIVE

This study explores the mechanism of cyclooxygenase-2 (COX-2) upregulation in oral cancers associated with macrophage by using molecular biology techniques and primary culture of murine macrophage.

METHODS

Murine macrophage was induced by macrophage colony-stimulating factor (M-CSF) and Cal27 conditional medium (CM). Purity of the macrophage was detected through CD68 immunofluorescence staining. Inhibitors of spleen tyrosine kinase (Syk) and nuclear factor κB (NFκB) were used to inhibit these pathways. In addition, real-time polymerase chain reaction and Western blot analysis were used to detect alterations in COX-2 and pathway-related proteins.

RESULTS

All of the induced cells specifically expressed CD68. Cal27 CM could significantly induce COX-2 expression (P<0.001). Moreover, inhibition of Syk pathway attenuated NFκB-P65 phosphorylation and reduced COX-2 expression (P<0.01), and inhibition of NFκB pathway exerted no effects on Syk phosphorylation but significantly inhibited COX-2 upregulation (P<0.01).

CONCLUSIONS

Syk-NFκB is responsible for COX-2 overexpression in oral cancer associated with macrophages. Targeting this pathway is possibly a new approach to control oral cancer-related pain.
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