Search

Arginine methyltransferases critically regulate cellular homeostasis by modulating the functional outcome of their substrates. The protein arginine methyltransferase 5 (PRMT5) is an enzyme involved in growth and survival pathways promoting tumorigenesis. However, little is known about the biologic function of PRMT5 and its therapeutic potential in multiple myeloma (MM). In the present study, we identified and validated PRMT5 as a new therapeutic target in MM. PRMT5 is overexpressed in patient MM cells and associated with decreased progression-free survival and overall survival. Either genetic knockdown or pharmacological inhibition of PRMT5 with the inhibitor EPZ015666 significantly inhibited growth of both cell lines and patient MM cells. Furthermore, PRMT5 inhibition abrogated NF-κB signaling. Interestingly, mass spectrometry identified a tripartite motif-containing protein 21 TRIM21 as a new PRMT5-partner, and we delineated a TRIM21-dependent mechanism of NF-κB inhibition. Importantly, oral administration of EPZ015666 significantly decreased MM growth in a humanized murine model of MM. These data both demonstrate the oncogenic role and prognostic relevance of PRMT5 in MM pathogenesis, and provide the rationale for novel therapies targeting PRMT5 to improve patient outcome.

14-3-3 proteins are a family of master regulators of intracellular signaling, yet their impact on proteasome function is unknown. We demonstrate that 14-3-3? binds the 11S proteasome activator, limiting proteasome assembly and cellular capacity for protein degradation. To define the functional impact of 14-3-3? proteasomal binding in myeloma cells, silencing and overexpression experiments are performed. We find that downregulation of 14-3-3? impairs myeloma cell growth and confers resistance to clinically used proteasome inhibitors. In a large cohort of newly diagnosed myeloma patients, elevated expression of 14-3-3? is associated with high risk myeloma genetic subtypes and worse prognosis overall. Our work demonstrates the important role of 14-3-3? in regulating proteasome function, myeloma cell growth and sensitivity to therapeutics, and suggests regulation of 14-3-3? as a new approach in myeloma therapy.

Despite the development of novel drugs, alkylating agents remain an important component of therapy in multiple myeloma (MM). DNA repair processes contribute towards sensitivity to alkylating agents and therefore we here evaluate the role of nucleotide excision repair (NER), which is involved in the removal of bulky adducts and DNA crosslinks in MM. We first evaluated NER activity using a novel functional assay and observed a heterogeneous NER efficiency in MM cell lines and patient samples. Using next-generation sequencing data, we identified that expression of the canonical NER gene, excision repair cross-complementation group 3 (ERCC3), significantly impacted the outcome in newly diagnosed MM patients treated with alkylating agents. Next, using small RNA interference, stable knockdown and overexpression, and small-molecule inhibitors targeting xeroderma pigmentosum complementation group B (XPB), the DNA helicase encoded by ERCC3, we demonstrate that NER inhibition significantly increases sensitivity and overcomes resistance to alkylating agents in MM. Moreover, inhibiting XPB leads to the dual inhibition of NER and transcription and is particularly efficient in myeloma cells. Altogether, we show that NER impacts alkylating agents sensitivity in myeloma cells and identify ERCC3 as a potential therapeutic target in MM.

Proteasome inhibition is an effective therapy for multiple myeloma (MM) patients; however, the emergence of drug resistance is common. Novel therapeutic strategies to overcome proteasome inhibitor resistance are needed. In this study, we examined whether targeting deubiquitylating (DUB) enzymes upstream of 20S proteasome overcomes proteasome inhibitor resistance. Gene expression analysis, immunohistochemical studies of MM patient bone marrow, reverse transcription–PCR and protein analysis show that Rpn11/POH1, a DUB enzyme upstream of 20S proteasome, is more highly expressed in patient MM cells than in normal plasma cells. Importantly, Rpn11 expression directly correlates with poor patient survival. Loss-of-function studies show that Rpn11-siRNA knockdown decreases MM cell viability. Pharmacological inhibition of Rpn11 with O-phenanthroline (OPA) blocks cellular proteasome function, induces apoptosis in MM cells and overcomes resistance to proteasome inhibitor bortezomib. Mechanistically, Rpn11 inhibition in MM cells activates caspase cascade and endoplasmic stress response signaling. Human MM xenograft model studies demonstrate that OPA treatment reduces progression of tumor growth and prolongs survival in mice. Finally, blockade of Rpn11 increases the cytotoxic activity of anti-MM agents lenalidomide, pomalidomide or dexamethasone. Overall, our preclinical data provide the rationale for targeting DUB enzyme Rpn11 upstream of 20S proteasome to enhance cytotoxicity and overcome proteasome inhibitor resistance in MM.

Immunotherapeutic approaches, particularly programmed death 1/programmed death ligand 1 (PD-1/PD-L1) blockade, have improved the treatment of non-small-cell lung cancer (NSCLC), supporting the premise that evasion of immune destruction is of importance for NSCLC progression. However, the signals responsible for upregulation of PD-L1 in NSCLC cells and whether they are integrated with the regulation of other immune-related genes are not known. Mucin 1 (MUC1) is aberrantly overexpressed in NSCLC, activates the nuclear factor-κB (NF-κB) p65→ZEB1 pathway and confers a poor prognosis. The present studies demonstrate that MUC1-C activates PD-L1 expression in NSCLC cells. We show that MUC1-C increases NF-κB p65 occupancy on the CD274/PD-L1promoter and thereby drives CD274transcription. Moreover, we demonstrate that MUC1-C-induced activation of NF-κB→ZEB1 signaling represses the TLR9(toll-like receptor 9), IFNG, MCP-1(monocyte chemoattractant protein-1) and GM-CSFgenes, and that this signature is associated with decreases in overall survival. In concert with these results, targeting MUC1-C in NSCLC tumors suppresses PD-L1 and induces these effectors of innate and adaptive immunity. These findings support a previously unrecognized central role for MUC1-C in integrating PD-L1 activation with suppression of immune effectors and poor clinical outcome.

The aim of this study was to evaluate the clinical value of CEA and CA 19-9 in a potential high-risk population of subjects with gastrointestinal complaints. The basic question was whether the determination of these markers, in addition to some other clinical features in this high risk population, could be helpful in diagnosing intraabdominal cancer. Two hundred and two patients with gastrointestinal complaints underwent standard diagnostic procedures and were followed for at least one year. For every patient, CEA and CA 19-9 levels were obtained at the first examination; the evaluating physician was blinded to the marker levels. The determinants of the likelihood of cancer were evaluated by multivariate analysis. Seventeen patients were diagnosed as having intraabdominal cancers. With the presence of melena (RR=101.63, p=0.007), nonspecific gastrointestinal symptoms (RR=12.54, p=0.026), increasing age (RR=1.09, p=0.028) and abnormal CEA (RR=240.79, p=0.000), the risk of having cancer increased significantly and independently. The presence of a primary gastric complaint was associated with a lower risk of cancer in this cohort (RR=0.01, p=0.04). Markers were not used in the diagnostic workup. In conclusion, in patients presenting with gastrointestinal complaints, the finding of elevated CEA levels may help in the diagnosis of cancer by prompting a more extensive search for intraabdominal cancer.

The object of this study was to investigate how the information status with regard to diagnosis, in addition to social and clinical factors, influenced emotional functioning and quality of life in a group of cancer patients in Turkey. A consecutive sample of 100 cancer patients being treated for different diagnoses in a tertiary care centre were prospectively evaluated. Data on patient disease and social characteristics, clinical factors, and scores on the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) were analysed by logistic regression models. A significant proportion (44%) of the patients did not know of their diagnosis of cancer. The scores on functional and symptom scales and global health status/quality of life according to QLQ-C30 did not differ according to the information given or not given on diagnosis. However, the independently significant determinants of good emotional functioning were male gender (P=0.002), low serum alanine transferase levels (P=0.025), good social functioning (P=0.002), and the absence of constipation (P=0.005). In Turkey, it is still common for cancer patients not to be informed of their diagnosis, and there is a great need to improve this situation. Honest disclosure of the truth does not worsen any dimension of quality of life in general or emotional functioning in particular. On the contrary, those with hepatic dysfunction, female gender, poor social functioning and constipation are the ones at increased risk of poor emotional functioning, and these patients may benefit from psychological screening.

Background. To investigate the correlation among some of the commonly used clinical, pathological factors and newer biological indicators, and to identify the independent predictors of distant metastasis at presentation in patients with breast cancer. Methods. The pathological specimens from 73 patients with breast cancer were retrospectively evaluated by immunohistochemistry. Data on 13 biological indicators; ER, PR, P53, c-erbB-2, PCNA, CEA, Ki-67, Vimentin, Ulex, Nm23, Cathepsin D, Factor VIII, PS2 together with clinical and pathological factors were collected. Results. A number of highly significant correlations were found among the biological indicators studied. By logistic regression analysis, the predictors of distant metastasis at presentation in univariate tests were tumor diameter, number of lymph nodes involved, P53, c-erbB-2and grade. In multivariate analysis, tumor diameter (P=0.042, HR: 1.88(1.02–3.44)), c-erbB-2expression (P=0.035, HR: 18.20 (1.23–268.66)) and grade (P=0.010, HR: 8.05(1.66–39.00)) retained their significance. Conclusion. Our findings show that inactivation of suppressor genes, expression of oncogenes, loss of differentiation, augmentation of proliferative activity, metastatic potential, angiogenesis and hormone receptor status are all interrelated facets of breast cancer pathogenesis. Patients with tumors overexpressing c-erbB-2 or with bigger or higher-grade tumors probably need to be more carefully evaluated for the presence of distant metastasis, thus be better staged, at presentation. This may be a new reason to test c-erbB-2routinely in all patients with breast cancer in addition to its well-known prognostic and predictive uses.

Abstract: The aim of this study was to evaluate the efficacy of low dose oral clodronate in palliation of pain arising from bone metastases (BM) and to determine the optimal oral clodronate dose which inhibits osteolysis caused by tumor. Fifty patients with bone pain caused by BM were included in this study. All were receiving antitumor chemotherapy or hormonal therapy. The patients were randomized into three groups according to the dose of clodronate. Groups A and B were given 800 mg/d and 1600 mg/d of oral clodronate respectively for 3 months. Group C was the control group. The effect of clodronate in pain palliation was evaluated with pain score, performance status, and changes in analgesic use. The effect on osteolysis was examined with urinary calcium, hydroxyproline (OHP) and serum cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) levels. Group A contained 16 patients, and groups B and C contained 17 patients each. After 3 months use of oral clodronate, significant decrease in the pain score of groups A and B was noted when, compared to group C (P=0.024 andP=0.007, respectively) The analgesic use of 11 patients in group A (69%) and 8 patients in group B (47%) was decreased, but only the decrease in group A was statistically significant (P=0.038). Pain score increased in 5 patients in group C (29%), and 3 patients in groups A (19%) and B (18%) each. Urinary calcium, OHP and serum ICTP levels increased in group C and decreased in groups A and B, but only the decrease of urinary calcium levels of group B was significant (P=0.003). In conclusion, low dose (800 mg/d) oral clodronate seems to be as effective as standard dose (1600 mg/d) in palliation of bone pain secondary to BM.

The aim of this study was to evaluate the efficacy of low dose oral clodronate in palliation of pain arising from bone metastases (BM) and to determine the optimal oral clodronate dose which inhibits osteolysis caused by tumor. Fifty patients with bone pain caused by BM were included in this study. All were receiving antitumor chemotherapy or hormonal therapy. The patients were randomized into three groups according to the dose of clodronate. Groups A and B were given 800 mg/d and 1600 mg/d of oral clodronate respectively for 3 months. Group C was the control group. The effect of clodronate in pain palliation was evaluated with pain score, performance status, and changes in analgesic use. The effect on osteolysis was examined with urinary calcium, hydroxyproline (OHP) and serum cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) levels. Group A contained 16 patients, and groups B and C contained 17 patients each. After 3 months use of oral clodronate, significant decrease in the pain score of groups A and B was noted when, compared to group C (P=0.024 andP=0.007, respectively) The analgesic use of 11 patients in group A (69%) and 8 patients in group B (47%) was decreased, but only the decrease in group A was statistically significant (P=0.038). Pain score increased in 5 patients in group C (29%), and 3 patients in groups A (19%) and B (18%) each. Urinary calcium, OHP and serum ICTP levels increased in group C and decreased in groups A and B, but only the decrease of urinary calcium levels of group B was significant (P=0.003). In conclusion, low dose (800 mg/d) oral clodronate seems to be as effective as standard dose (1600 mg/d) in palliation of bone pain secondary to BM.

In this study, we presented the results of the CHOP ± bleomycine treatment and evaluation of prognostic factors in 93 patients with aggressive lymphoma. Mean age was 43 (15–82) years; male/female ratio was 55/38. Primary extranodal lymphoma, most frequently gastric and intestinal, was found in 19 (20%) patients. Distributions of patients according to the clinical stages were: 15% in stage I, 44% in stage II, 24% in stage III and 17% in stage IV Performance status (FS) (ECOG) of the patients were: 15% in PS 0, 53% in PS 1, 21% in PS 2 and 11% in PS 3. Serum LDH levels were elevated in 41 patients (49.4%). Seven patients with primary extranodal lymphoma received adjuvant chemotherapy following surgery. Excluding these patients, the overall response rate was 83% (69% complete remission (CR)). Three-year-disease-free and overall survivals were 67% and 57%, respectively. Ninety percent or over dose intensity was achieved in 50% of the patients. Treatment tox-icities were within acceptable limits with 10% of patients having grade 3–4 hematologic toxicity. Age, PS, stage, number of the extranodal involvement sites (NEIS), B symptoms and LDH were examined as prognostic factors. PS (0–1 vs 2–4) and stage were found to be significant in complete remission rate (P=0.025 and P=0.040, respectively). LDH, stage, NEIS (≤1 vs l) and PS were determined to be significant factors for overall survival in univariate analysis (P=0.0345, P=0.0005, P=0.0030, and P=0.0027, respectively). Multivariate analysis yielded PS and NEIS as independent factors (P=0.019 and P=0.018, respectively). Only NEIS was found to be the independent factor in our patients younger than 60 (P=0.009) in contrast to the international prognostic index. A modified age adjusted index including stage, LDH, PS and NEIS was found to be an important factor for both complete remission rate (P=0.017) and overall survival (P<0.00001) in this study.