Germline MBD4 deficiency causes a multi-tumor predisposition syndrome.

We report an autosomal recessive, multi-organ tumor predisposition syndrome, caused by bi-allelic loss-of-function germline variants in the base excision repair (BER) gene MBD4. We identified five individuals with bi-allelic MBD4 variants within four families and these individuals had a personal and/or family history of adenomatous colorectal polyposis, acute myeloid leukemia, and uveal melanoma. MBD4 encodes a glycosylase involved in repair of G:T mismatches resulting from deamination of 5'-methylcytosine. The colorectal adenomas from MBD4-deficient individuals showed a mutator phenotype attributable to mutational signature SBS1, consistent with the function of MBD4. MBD4-deficient polyps harbored somatic mutations in similar driver genes to sporadic colorectal tumors, although AMER1 mutations were more common and KRAS mutations less frequent. Our findings expand the role of BER deficiencies in tumor predisposition. Inclusion of MBD4 in genetic testing for polyposis and multi-tumor phenotypes is warranted to improve disease management.

Macrophage- and BCR-derived but not TLR-derived signals support the growth of CLL and Richter syndrome murine models in vivo.

A large amount of circumstantial evidence has accumulated suggesting that Toll-like receptor (TLR) signals are involved in driving chronic lymphocytic leukemia (CLL) cell proliferation, but direct in vivo evidence for this is still lacking. We have now further addressed this possibility by pharmacologically inhibiting or genetically inactivating the TLR pathway in murine CLL and human Richter syndrome (RS) patient-derived xenograft (PDX) cells. Surprisingly, we show that pharmacologic inhibition of TLR signaling by treatment with an IRAK1/4 inhibitor delays the growth of the transplanted malignant cells in recipient mice, but genetic inactivation of the same pathway by CRISPR/Cas9-mediated disruption of IRAK4 or its proximal adaptor MyD88 has no effect. We further show that treatment with the IRAK1/4 inhibitor results in depletion of macrophages and demonstrate that these cells can support the survival and enhance the proliferation of both murine Eµ-TCL1 leukemia and human RS cells. We also show that genetic disruption of the B-cell receptor (BCR) by CRISPR/Cas9 editing of the immunoglobulin M constant region gene inhibits the growth of human RS-PDX cells in vivo, consistent with our previous finding with murine Eµ-TCL1 leukemia cells. Finally, we show that genetic disruption of IRAK4 does not result in negative selection of human CLL cell lines xenografted in immunodeficient mice. The obtained data suggest that TLR signals are unlikely to represent a major driver of CLL/RS cell proliferation and provide further evidence that signals from macrophages and the BCR promote the growth and survival of CLL and RS cells in vivo.

B-cell receptor signaling and genetic lesions in TP53 and CDKN2A/CDKN2B cooperate in Richter transformation.

B-cell receptor (BCR) signals play a critical role in the pathogenesis of chronic lymphocytic leukemia (CLL), but their role in regulating CLL cell proliferation has still not been firmly established. Unlike normal B cells, CLL cells do not proliferate in vitro upon engagement of the BCR, suggesting that CLL cell proliferation is regulated by other signals from the microenvironment, such as those provided by Toll-like receptors or T cells. Here, we report that BCR engagement of human and murine CLL cells induces several positive regulators of the cell cycle, but simultaneously induces the negative regulators CDKN1A, CDKN2A, and CDKN2B, which block cell-cycle progression. We further show that introduction of genetic lesions that downregulate these cell-cycle inhibitors, such as inactivating lesions in CDKN2A, CDKN2B, and the CDKN1A regulator TP53, leads to more aggressive disease in a murine in vivo CLL model and spontaneous proliferation in vitro that is BCR dependent but independent of costimulatory signals. Importantly, inactivating lesions in CDKN2A, CDKN2B, and TP53 frequently co-occur in Richter syndrome (RS), and BCR stimulation of human RS cells with such lesions is sufficient to induce proliferation. We also show that tumor cells with combined TP53 and CDKN2A/2B abnormalities remain sensitive to BCR-inhibitor treatment and are synergistically sensitive to the combination of a BCR and cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor both in vitro and in vivo. These data provide evidence that BCR signals are directly involved in driving CLL cell proliferation and reveal a novel mechanism of Richter transformation.

NFKBIE mutations are selected by the tumor microenvironment and contribute to immune escape in chronic lymphocytic leukemia.

Loss-of-function mutations in NFKBIE, which encodes for the NF-κB inhibitor IκBε, are frequent in chronic lymphocytic leukemia (CLL) and certain other B-cell malignancies and have been associated with accelerated disease progression and inferior responses to chemotherapy. Using in vitro and in vivo murine models and primary patient samples, we now show that NFKBIE-mutated CLL cells are selected by microenvironmental signals that activate the NF-κB pathway and induce alterations within the tumor microenvironment that can allow for immune escape, including expansion of CD8+ T-cells with an exhausted phenotype and increased PD-L1 expression on the malignant B-cells. Consistent with the latter observations, we find increased expression of exhaustion markers on T-cells from patients with NFKBIE-mutated CLL. In addition, we show that NFKBIE-mutated murine CLL cells display selective resistance to ibrutinib and report inferior outcomes to ibrutinib treatment in NFKBIE-mutated CLL patients. These findings suggest that NFKBIE mutations can contribute to CLL progression through multiple mechanisms, including a bidirectional crosstalk with the microenvironment and reduced sensitivity to BTK inhibitor treatment.

A novel germline MLH1 mutation causing Lynch Syndrome in patients from the Republic of Macedonia.

AIM: To implement molecular analysis in the clinical diagnosis and management of Lynch syndrome (LS). METHODS: We analyzed the mutations in MLH1 and MSH2 in the selected LS families from the Republic of Macedonia. RESULTS: We performed the very first genetic identification of LS families and characterized a novel mutation. The novel nonsense germline point mutation c.392C>G in the codon 131 of MLH1(S131X) was identified as the underlying genetic cause of LS in three families. The haplotype analysis suggested a founder effect of this mutation in our population. CONCLUSION: We expect to detect the mutation in other LS patients from the region, and recommend cost-effective screening for this mutation by restriction fragment length polymorphism-polymerase chain reaction or DNA sequencing of MLH1 Exon5 prior to full genetic testing in all LS suspects of Macedonian ancestry.

The AKR1D1*36 (rs1872930) Allelic Variant Is Independently Associated With Clopidogrel Treatment Outcome.

AIMS: The present observational cohort study evaluated the association between the AKR1D1*36 (rs1872930) allele and the risk of major adverse cardiovascular and cerebrovascular events (MACCE) in clopidogrel treated patients. METHODS: We screened 198 consecutive cardiovascular patients on clopidogrel therapy admitted in October to November 2010 with cardiovascular or cerebrovascular symptoms; of these 118 met the study protocol entry criteria; the median age of the cohort was 62.5 years (IQR 57-66 years), and 55% were females. RESULTS: The median follow up time was 38.5 (IQR 24-48) months; Kaplan-Meier/Log-rank analysis showed that patients carrying the AKR1D1*36 allelic variant have a shorter event-free-survival compared to wild type patients, hazard ratio = 2.193 (95% CI, 1.091 to 4.406); p = 0.0155. Multivariable Cox regression analysis confirmed the AKR1D1*36 allele as an independent risk factor (HR = 2.36; 95% CI, 1.34 to 4.18) and identified 3 other risk factors for MACCE; previous percutaneous interventions (PCI), HR = 2.78; (95% CI, 1.34 to 5.78), and a history of myocardial infarction, HR = 2.62; (95% CI, 1.48 to 4.64) at baseline and the previously reported CYP2C19*2 polymorphism (HR = 2.33; 95% CI, 1.33 to 4.06). CONCLUSION: The AKR1D1*36 (rs1872930) variant is independently associated with a higher risk for MACCE and shorter event-free survival time.

Mutational Signature Analysis Reveals NTHL1 Deficiency to Cause a Multi-tumor Phenotype.

Biallelic germline mutations affecting NTHL1 predispose carriers to adenomatous polyposis and colorectal cancer, but the complete phenotype is unknown. We describe 29 individuals carrying biallelic germline NTHL1 mutations from 17 families, of which 26 developed one (n = 10) or multiple (n = 16) malignancies in 14 different tissues. An unexpected high breast cancer incidence was observed in female carriers (60%). Mutational signature analysis of 14 tumors from 7 organs revealed that NTHL1 deficiency underlies the main mutational process in all but one of the tumors (93%). These results reveal NTHL1 as a multi-tumor predisposition gene with a high lifetime risk for extracolonic cancers and a typical mutational signature observed across tumor types, which can assist in the recognition of this syndrome.

Manganese superoxide dismutase (MnSOD) genetic polymorphism is associated with risk of early-onset prostate cancer.

Prostate cancer continues to be the most frequently diagnosed neoplasm, and the second leading cause of cancer-related mortality in men. Oxidative stress may enhance prostatic carcinogenesis. Manganese superoxide dismutase (MnSOD) is the only known superoxide scavenger in mitochondria. It plays a key role in antioxidant defense as mitochondria are important for oxidative metabolism coupled to the electron transport chain and oxidative phosphorylation and hence, ROS production. A T-->C single nucleotide substitution, resulting in a Val-->Ala change at position 9 (Ala-9Val), which alters the secondary structure of the protein, has been noted to affect transport of MnSOD into the mitochondria. We have determined the MnSOD genotype in 85 prostate cancer cases and 151 control subjects. Ala-9Val polymorphism was determined using real time polymerase chain reaction (PCR) amplification with fluorescently labeled primers. No significant difference was found in prostate cancer susceptibility in the subjects with Ala/Ala and Val/Ala genotype compared with Val/Val genotype (Odds ratio (OR), 1.3; 95% confidence interval (95% CI), 0.69-2.42; p = 0.416). We did not observe an association of the MnSOD genotype or allele frequency between subgroups of cases divided by disease status (aggressive vs. non-aggressive prostate cancer). However, in the analyses stratified by the age at diagnosis we have observed that men homozygous for Ala had a 5.2-fold increased risk of early-onset prostate cancer (under age of 65) compared to men homozygous for Val allele (p = 0.05). These data suggest that Ala/Ala MnSOD genotype in the Macedonian population could have an influence on early onset of prostate cancer, but no impact on the subsequent development of the disease.

Original research paper. Hydrazinyldiene-chroman-2,4-diones in inducing growth arrest and apoptosis in breast cancer cells: Synergism with doxorubicin and correlation with physicochemical properties.

This study evaluates the effects of previously synthesized hydrazinyldiene-chroman-2,4-diones on cell proliferation and apoptosis, cell cycle distribution and migration capacity of MCF-7 breast cancer cells in synergy with doxorubicin. Physicochemical properties of the synthesized compounds were correlated with their structure and activity. Significant cell viability decrease in comparison with the effect of doxorubicin alone and the reference 4-hydroxycoumarin was observed when combination treatment comprising doxorubicin and the title compounds was applied. Synergistic effect with doxorubicin was also observed in down-regulation of phospho-Thr308Akt levels, confirming reduced proliferation and increased apoptosis. Combined treatment increased the percentage of cells arrested at the G2/M stage. Additive inhibition of cell migration was also observed, pointing to the possibility of reducing the risk of metastases. With their solubility profile and log D7.4, all the synthesized compounds follow Lipinski's rule of five for good permeability (absorption) potential.

Moleculary Confirmed, Cytogenetic Remission in a Case with Myelodysplastic Syndrome Treated with Azacitidne.

Myelodysplastic syndrome (MDS) is a diverse group of clonal hematologic neoplasms. The only curative treatment for MDS is allogeneic stem cell transplantation (SCT). Epigenetic changes play an important role in the pathogenesis of MDS and treatment with DNA methyl transferase inhibitors, Azacitidine, significantly prolong the survival of high-risk MDS patients. Here we report a case of a 58-year-old male presented with pancytopenia, macrocytosis, and hyperplastic bone marrow with 3-lineage dysplasia with ~14% of myeloid blasts. Cytogenetic studies with G banding showed normal karyotype. Multiplex ligation-dependent probe amplification (MLPA) screening for most predictive cytogenetic abnormalities of MDS showed loss of the Y chromosome. Those findings later were confirmed with Quantitative Fluorescent (QF)-PCR and specific MLPA for Y chromosome, showing loss of the Y chromosome in >80% of cells. He was diagnosed with MDS-RAEB2 according to 2008 WHO classification and stratified into high risk group (IPSS score 5). Unrelated allogeneic SCT was planed and bridging treatment with Azacitidine at a dose of 75mg/m2/daily subcutaneously for 7 days every 28 days was initiated. Hematologic improvements, according to the International Working Group 2006 criteria, were observed after 4 cycles of Azacitidine treatment. After 6 cycles, complete hematological remission was achieved. Interestingly, molecular analysis performed after the 8th cycle showed normal presence of Y chromosome indicating a cytogenetic remission, molecularly confirmed. Maintenance treatment with Azacitidine was assigned, and the scheduled SCT was postponed. Experience from our case showed that the loss of the Y chromosome was related to the disease onset, and indicated that Azacitidine might be consider as effective treatment for MDS cases associated with good cytogenetic.

Diversities of Calreticulin Gene Mutations in Macedonian Patients With Essential Thrombocythemia.

BACKGROUND: Acquired calreticulin (CALR) gene mutations are one of the molecular hallmarks of essential thrombocythemia (ET). It has been suggested that patients with ET with CALR mutations are associated with a distinct clinical phenotype. PATIENTS AND METHODS: We evaluated the clinical and molecular features of 150 patients with ET followed over a period of 15 years. The screening for the presence of insertion/deletion mutations in CALR exon 9 was done with a fluorescent polymerase chain reaction/capillary electrophoresis procedure. Sanger sequencing of CALR exon 9 was used for the characterization of mutations and for the analysis of triple-negative patients. RESULTS: CALR mutations were detected in 42 (28%) patients. The most common CALR mutations were type 1 and type 2, which were present in 11 (26.2%) and 20 (47.6%) patients, respectively. Additionally, 10 different small insertion/deletions (3 known and 7 new) were detected in 11 patients, resulting in an altered calreticulin C-terminal end. The clinical characteristics of all CALR+ patients with ET were in line with previously published data for this subset of patients. CONCLUSION: Our results showed that a wide range of different CALR mutations are associated with a distinct ET clinical phenotype that is associated with the male gender, younger age at diagnosis, higher platelet and lower leukocyte and erythrocyte counts and lower hemoglobin level, and a milder clinical course. The relatively high frequency of new insertion/deletion mutations indicate that the use of fluorescent polymerase chain reaction followed by capillary electrophoresis is the method of choice for the analysis of these defects.

A new case with 10q23 interstitial deletion encompassing both PTEN and BMPR1A narrows the genetic region deleted in juvenile polyposis syndrome.

We report on a patient with a contiguous interstitial germline deletion of chromosome 10q23, encompassing BMPR1A and PTEN, with clinical manifestations of juvenile polyposis and minor symptoms of Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRRS). The patient presented dysmorphic features as well as developmental delay at the age of 5 months. Multiple polyps along all parts of the colon were diagnosed at the age of 3 years, following an episode of a severe abdominal pain and intestinal bleeding. The high-resolution comparative genomic hybridisation revealed a 3.7-Mb deletion within the 10q23 chromosomal region: 86,329,859-90,035,024. The genotyping with four polymorphic microsatellite markers confirmed a de novo 10q deletion on the allele with a paternal origin, encompassing both PTEN and BMPR1A genes. The karyotype analysis additionally identified a balanced translocation involving chromosomes 5q and 7q, and an inversion at chromosome 2, i.e. 46,XY,t(5;7)(q13.3-q36), inv(2)(p25q34). Although many genetic defects were detected, it is most likely that the 10q23 deletion is primarily the cause for the serious phenotypic manifestations. The current clinical findings and deletion of BMPR1A indicate a diagnosis of severe juvenile polyposis, but the existing macrocephaly and PTEN deletion also point to either CS or BRRS, which cannot be ruled out at the moment because of their clinical manifestation later in life and the de novo character of the deletion. The deletion detected in our patient narrows the genetic region deleted in all reported cases with juvenile polyposis by 0.04 Mb from the telomeric side, mapping it to the region chr10:88.5-90.03Mb (GRCh37/hg19), with an overall length of 1.53 Mb.

Promoter length polymorphism in UGT1A1 and the risk of sporadic colorectal cancer.

Uridine diphosphoglucuronate glucuronosyltransferase 1A1 (UGT1A1) is the key hepatic detoxification enzyme involved in the biotransformation of many carcinogens implicated in the development of colon, breast, and prostate cancers in humans. A polymorphism in the UGT1A1 promoter containing a TA-repeat element [(TA)5-8TAA] is involved in the modulation of UGT1A1 transcriptional activity. The wild-type activity is associated with the (TA)6TAA allele (UGT1A1*1), whereas UGT1A1 expression decreases with the increase of the TA-repeat number. We hypothesize that the low-activity allele UGT1A1*28 with seven TA repeats is associated with a higher risk for colorectal cancer. Our study involved 168 patients with histopathologically confirmed sporadic colorectal cancer and a control group of 96 individuals with no personal history of colorectal cancer. We detected a higher frequency of UGT1A1*28 than the wild-type UGT1A1*1 allele in colorectal cancer patients as compared with that of controls (odds ratio [OR] = 1.55, 95% confidence interval [CI] = 1.07-2.26, P = 0.021). The frequency of genotypes containing the UGT1A1*28 allele in the homozygous or heterozygous state was significantly higher than the frequency of the wild-type UGT1A1*1/*1 genotype in colorectal cancer patients as compared with controls (OR = 2.0, 95% CI = 1.19-3.34, P = 0.007). Our results indicate that the UGT1A1*28 allele is a risk factor for colorectal cancer in the Macedonian male population, whereas no significant risk was detected among women.

Glutathione peroxidase 1 (GPX1) genetic polymorphism, erythrocyte GPX activity, and prostate cancer risk.

Glutathione peroxidase 1 (GPX1) is a ubiquitously expressed selenium-dependent enzyme that protects cells against oxidative damage by reducing hydrogen peroxide and a wide range of organic peroxides. Some epidemiological studies have correlated low GPX activity or particular GPX1 polymorphisms with enhanced risk of cancer, although these correlations have not been consistently observed in all populations. Therefore, we conducted the present study to evaluate the possible association of GPX1 Pro198Leu polymorphism and erythrocyte GPX activity with the risk of developing prostate cancer and to clarify whether erythrocyte GPX activity levels were correlated with the GPX1 Pro198Leu genotype in the Macedonian population. The GPX1 Pro198Leu genotype was determined in 82 prostate cancer cases and 123 control individuals. We found an overall protective effect of the variant Leu allele of the GPX1 polymorphism on the prostate cancer risk. Heterozygous carriers of the variant Leu allele had a significantly lower risk of prostate cancer compared with homozygous wild-type individuals (OR, 0.38; 95% CI, 0.20-0.75; P = 0.004). Erythrocyte GPX activity was analyzed in 73 cases and 91 controls. The erythrocyte GPX activity in the cancer group was lower than in the healthy controls. Additionally, we compared the erythrocyte GPX activity in the control group of 90 subjects and found no significant differences by genotype. These findings suggest that individual susceptibility of prostate cancer may be modulated by GPX1 polymorphism and that the combination of genetic factors involved in oxidative response with environmental carcinogens may play an important role in prostate carcinogenesis.

Increased oxidative/nitrosative stress and decreased antioxidant enzyme activities in prostate cancer.

OBJECTIVES: The study was aimed to evaluate the oxidative/nitrosative stress status in prostate cancer (CaP) and benign prostatic hyperplasia (BPH). DESIGN AND METHODS: 312 men from two different populations were included: 163 men from Macedonia (73 CaP patients, 67 BPH patients and 23 control subjects) and 149 men from Turkey (34 prostate cancer patients, 100 BPH patients and 15 control subjects). We measured erythrocyte malondialdehyde (MDA) levels, erythrocyte activities of superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPX) and catalase (CAT); plasma nitrite/nitrate (NO(2)(-)/NO(3)(-)), cGMP and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. RESULTS: A similar pattern of alteration in the oxidative/nitrosative stress-related parameters was found in both, Macedonian and Turkish studied samples: higher MDA concentrations with lower GPX and CuZn-SOD activities in CaP patients versus controls and BPH groups. The CAT activity was decreased in the CaP patients versus controls in the Turkish studied sample. Furthermore, CaP patients had increased plasma NO(2)(-)/NO(3)(-) and cGMP levels versus controls and BPH groups in both studied samples. CONCLUSIONS: This study has confirmed an imbalance in the oxidative stress/antioxidant status and revealed an altered nitrosative status in prostate cancer patients.