Antitumor efficacy of arsenic/interferon in preclinical models of chronic myeloid leukemia resistant to tyrosine kinase inhibitors.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) are the standard treatment for chronic myeloid leukemia (CML). Despite their clinical success, TKIs are faced with challenges such as treatment resistance, which may be driven by kinase domain mutations, and frequent disease relapse upon the cessation of treatment. The combination of arsenic trioxide (ATO) and interferon-α (IFN) was previously demonstrated to inhibit proliferation and induce apoptosis in CML cell lines, prolong the survival of primary wild-type CML mice, and dramatically decrease the activity of leukemia-initiating cells (LICs). METHODS: The ATO/IFN combination was tested in vitro on imatinib (IMN)-resistant K562-R and Ar230-R cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assays were used to evaluate proliferation and apoptosis, respectively. The acridine orange assay was used to assess autophagy, and quantitative reverse transcription-polymerase chain reaction was used to assess the involvement of the hedgehog (Hh) pathway. In vivo, a retroviral transduction/transplantation T315I BCR-ABL CML mouse model was used to assay the effect of the treatment on survival, tumor burden (histopathology and blood counts), and LIC activity (secondary transplantation). RESULTS: In vitro, ATO/IFN synergized to inhibit proliferation and induce apoptosis of IMN-resistant cells with variant modes of resistance. Furthermore, the preclinical effects of ATO/IFN were associated with induction of autophagy along with inhibition of the Hh pathway. Most remarkably, ATO/IFN significantly prolonged the survival of primary T315I-CML mice and displayed a dramatic impairment of disease engraftment in secondary mice, which reflected decreased LIC activity. CONCLUSIONS: Collectively, the ATO/IFN strategy has been demonstrated to have the potential to lead to durable remissions in TKI-resistant CML preclinical models and to overcome various TKI-specific mechanisms of resistance.

Preclinical efficacy of the synthetic retinoid ST1926 for treating adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). The HTLV-1 oncoprotein Tax plays an important role in ATL pathogenesis. ATL carries a poor prognosis due to chemotherapy resistance, stressing the need for alternative therapies. Here, we investigate the preclinical efficacy of the synthetic retinoid ST1926 in ATL and peripheral T-cell lymphomas. Clinically achievable concentrations of ST1926 induced a dramatic inhibition of cell proliferation in malignant T-cell lines and primary ATL cells with minimal effect on resting or activated normal lymphocytes. ST1926 induced apoptosis, DNA damage, and upregulation of p53 proteins in malignant T cells, whereas it caused an early downregulation of Tax proteins in HTLV-1-positive cells. In murine ATL, oral treatment with ST1926 prolonged survival and reduced leukemia cell infiltration, white blood cell counts, and spleen mass. In spleens of ST1926-treated animals, p53 and p21 proteins were upregulated, poly (ADP-ribose) polymerase was cleaved, and Tax transcripts were reduced. These results highlight the promising use of ST1926 as a targeted therapy for ATL.

ST1926, an orally active synthetic retinoid, induces apoptosis in chronic myeloid leukemia cells and prolongs survival in a murine model.

The tyrosine kinase inhibitor, imatinib, is the first line of treatment for chronic myeloid leukemia (CML) patients. Unfortunately, patients develop resistance and relapse due to bcr-abl point mutations and the persistence of leukemia initiating cells (LIC). Retinoids regulate vital biological processes such as cellular proliferation, apoptosis, and differentiation, in particular of hematopoietic progenitor cells. The clinical usage of natural retinoids is hindered by acquired resistance and undesirable side effects. However, bioavailable and less toxic synthetic retinoids, such as the atypical adamantyl retinoid ST1926, have been developed and tested in cancer clinical trials. We investigated the preclinical efficacy of the synthetic retinoid ST1926 using human CML cell lines and the murine bone marrow transduction/transplantation CML model. In vitro, ST1926 induced irreversible growth inhibition, cell cycle arrest and apoptosis through the dissipation of the mitochondrial membrane potential and caspase activation. Furthermore, ST1926 induced DNA damage and downregulated BCR-ABL. Most importantly, oral treatment with ST1926 significantly prolonged the longevity of primary CML mice, and reduced tumor burden. However, ST1926 did not eradicate LIC, evident by the ability of splenocytes isolated from treated primary mice to develop CML in untreated secondary recipients. These results support a potential therapeutic use of ST1926 in CML targeted therapy.

Effective targeting of chronic myeloid leukemia initiating activity with the combination of arsenic trioxide and interferon alpha.

Imatinib is the standard of care in chronic meloid leukemia (CML) therapy. However, imatinib is not curative since most patients who discontinue therapy relapse indicating that leukemia initiating cells (LIC) are resistant. Interferon alpha (IFN) induces hematologic and cytogenetic remissions and interestingly, improved outcome was reported with the combination of interferon and imatinib. Arsenic trioxide was suggested to decrease CML LIC. We investigated the effects of arsenic and IFN on human CML cell lines or primary cells and the bone marrow retroviral transduction/transplantation murine CML model. In vitro, the combination of arsenic and IFN inhibited proliferation and activated apoptosis. Importantly, arsenic and IFN synergistically reduced the clonogenic activity of primary bone marrow cells derived from CML patients. Finally, in vivo, combined interferon and arsenic treatment, but not single agents, prolonged the survival of primary CML mice. Importantly, the combination severely impaired engraftment into untreated secondary recipients, with some recipients never developing the disease, demonstrating a dramatic decrease in CML LIC activity. Arsenic/IFN effect on CML LIC activity was significantly superior to that of imatinib. These results support further exploration of this combination, alone or with imatinib aiming at achieving CML eradication rather than long-term disease control.

Prediction of celiac disease at endoscopy.

BACKGROUND AND STUDY AIMS: Celiac disease is increasingly recognized worldwide, but guidelines on how to detect the condition and diagnose patients are unclear. In this study the prevalence and predictors of celiac disease were prospectively determined in a cross-sectional sample of Lebanese patients undergoing esophagogastroduodenoscopy (EGD). PATIENTS AND METHODS: Consecutive consenting patients (n = 999) undergoing EGD answered a questionnaire and had blood taken for serologic testing. Endoscopic markers for celiac disease were documented and duodenal biopsies were obtained. The diagnosis of celiac disease was based on abnormal duodenal histology and positive serology. Risk factors were used to classify patients to either high or low risk for celiac disease. Independent predictors of celiac disease were derived via multivariate logistic regression. RESULTS: Villous atrophy (Marsh 3) and celiac disease were present in 1.8 % and 1.5 % of patients, respectively. Most were missed on clinical and endoscopic grounds. The sensitivity of tissue transglutaminase (tTG) testing for the diagnosis of villous atrophy and celiac disease was 72.2 % and 86.7 %, respectively. The positive predictive value of the deamidated gliadin peptide (DGP) test was 34.2 % and that of a strongly positive tTG was 80 %. While the strongest predictor of celiac disease was a positive tTG (odds ratio [OR] 131.7, 95 % confidence interval [CI] 29.0 - 598.6), endoscopic features of villous atrophy (OR 64.8, 95 %CI 10.7 - 391.3), history of eczema (OR 4.6, 95 %CI 0.8 - 28.8), anemia (OR 6.7, 95 %CI 1.2 - 38.4), and being Shiite (OR 5.4, 95 %CI 1.1 - 26.6) significantly predicted celiac disease. A strategy of biopsying the duodenum based on independent predictors had a sensitivity of 93 % - 100 % for the diagnosis of celiac disease, with an acceptable (22 % - 26 %) rate of performing unnecessary biopsies. A strategy that excluded pre-EGD serology produced a sensitivity of 93 % - 94 % and an unnecessary biopsy rate of 52 %. CONCLUSION: An approach based solely on standard clinical suspicion and endoscopic findings is associated with a significant miss rate for celiac disease. A strategy to biopsy based on the derived celiac disease prediction models using easily obtained information prior to or during endoscopy, maximized the diagnosis while minimizing unnecessary biopsies.

ASPL-TFE3 translocation in vulvovaginal alveolar soft part sarcoma.

Alveolar soft part sarcoma of the vulvovaginal region is limited to only 8 reported vaginal cases and 1 vulvar case in the English literature. The histogenesis of the tumor remains intriguing with postulates favoring a myogenic versus nonmyogenic origin. A reciprocal translocation for ASPL-TFE3 gene fusion, frequently detected in ~90% of cases, combined with TFE3 protein immunoexpression are highly sensitive and specific methods for diagnostic confirmation. The current report describes a unique case of vulvovaginal alveolar soft part sarcoma showing the classic morphologic features with documentation of TFE3 protein expression and the ASPL-TFE3 gene rearrangement. Furthermore, a brief review of the literature of vulvar and vaginal alveolar soft part sarcoma cases with the various treatment modalities is outlined.

Biospecimen Repositories in Low- and Middle-Income Countries: Insights From an American University of Beirut and Memorial Sloan Kettering Collaboration.

PURPOSE: Biobanking helps source tissue and blood for studying cancer genomics. Access to biorepository resources in low- and middle-income countries is lacking. Memorial Sloan Kettering Cancer Center (MSK) and the American University of Beirut (AUB) established a joint tissue biorepository at AUB in Beirut, Lebanon. The undertaking encountered key challenges that were unanticipated. MATERIALS AND METHODS: Patients age 18 years or older were eligible for enrollment at AUB. After consent, biospecimens were obtained at the time of routine diagnostic and/or therapeutic interventions. Both normal and abnormal tissue and solid and/or liquid specimens were collected from varied body sites. Early on, declining consent was frequently observed, and this was highlighted for investigation to understand potential participants reasoning. RESULTS: Of 850 patients approached, 704 (70.8%) elected to consent and 293 (29.5%) declined participation. The number of declined consents led to an amendment permitting the documentation of reasons for same. Of 100 potential participants who declined to consent and to whom outreach was undertaken, 63% indicated lack of research awareness and 27% deferral to their primary physician or family member. A financial gain for AUB was cited as concern by 5%, cultural boundaries in 4%, and 1% expressed concern about confidentiality. Of the patients who elected to consent, 682 biospecimens were procured. CONCLUSION: The AUB-MSK biospecimen repository has provided a unique resource for interrogation. Patient participation rate was high, and analyses of those who elected not to consent (29%) provide important insights into educational need and the local and cultural awareness and norms.

Variability in hormone and growth factor receptor expression in primary versus recurrent, metastatic, and post-neoadjuvant breast carcinoma.

The introduction of selective molecular targeted therapy, specifically tamoxifen and trastuzumab, has significantly altered the clinical behavior of breast carcinoma. Several questions remain, however, regarding potential phenotypic drifts in estrogen receptor (ER), progesterone receptor (PR), and epidermal growth factor receptor (Her-2/neu) expression between the primary and metastatic site. Whether patients should be tested for ER, PR, and Her-2/neu expression in the nodal or distant metastatic site, local recurrence and following neoadjuvant therapy, and whether this has an effect on prognosis remains elusive. A review of 45 studies addressing ER, PR, and Her-2/neu expression in lymph node metastasis, distant metastasis, local recurrence, and post-neoadjuvant therapy revealed the following average phenotypic drift in ER, PR, and Her-2/neu expression, respectively: 13.1 % (median = 10.0 %), 13.8 % (median = 16.0 %), and 7.7 % (median = 5.0 %) for lymph node metastasis; 21.8 % (median = 19.5 %), 30.8 % (median = 33.5 %), and 7.6 % (median = 6.1 %) for distant metastasis; 19.8 % (median = 13.4 %), 27.1 % (median = 28.6 %), and 6.6 % (median = 1.6 %) for local recurrence; and 12.9 % (median = 8.0 %), 32.0 % (median = 20.0 %), and 8.9 % (median = 0 %) post-neoadjuvant therapy. The above findings support the notion of re-evaluating ER, PR, and Her-2/neu expression in distant metastasis, lymph node metastasis and to a lesser extent local recurrence. The effects of neoadjuvant therapy on receptor expression are more pronounced for PR, which may have a prognostic role in therapy efficacy.

Chromatid recommensuration after segmental duplication.

BACKGROUND: Midsegment duplication (dup) of chromatid arms may be symmetric or asymmetric. It can be argued that every dup should yield a discommensured RC with (a) loss of at least one duplicated unit to the template counterpart and; (b) deletion of all sections of the replicating chromatid arm that are distal to both the gap left by the duplicating process and the segment closest to the centromere. HYPOTHESIS: Mechanisms capable of recommensuring the stack of chromatids after topological shifts of duplicated units (dups) are discussed. The mechanics might fail in few cases, which are discussed in terms of statistics and scalability. CONCLUSION: The dynamics of the highly non-linear processes discussed here may be relevant to duplications of smaller (epsilon) subunits such as telomeric units within malignant genomes.

Second primary malignancy after radical prostatectomy in a cohort from the Middle East.

BACKGROUND: Data from the Middle East regarding second primary malignancy (SPM) after radical prostatectomy are limited. Our objective was to estimate the overall risk of developing second primary malignancy (SPM) among Middle Eastern men with prostate cancer who underwent surgical extirpation of their prostate. MATERIALS AND METHODS: We conducted a retrospective study of 406 patients who underwent radical prostatectomy in a tertiary centre and who had no evidence of previous malignancy from 1998 to 2012. Standardized incidence ratios (SIRs) and 95% confidence interval (CI) were calculated to analyze the risk of SPM in our population compared with the general population. Cox-regression models were also conducted to correlate the clinicopathological factors with the development of SPM. RESULTS: After 14 years of follow-up, the incidence rate of SPM was 100.9 per 1,000 person-years. The most frequent SPMs were bladder cancer (n = 11, 27%) followed by hematological malignancies (n = 9, 22%) and lung cancer (n = 7, 17%). The overall risk for men with prostate cancer to develop SPM is lower than the men in the general population (standardized incidence ratios = 0.19; 95% CI: 0.14-0.25). A multivariate analysis failed to correlate any of the clinicopathological factors with the development of SPM. CONCLUSION: Patients with prostate cancer who underwent surgical expiration of their prostate are at lower risk of developing SPM compared with the general population.

Phosphorus Supplementation Mitigated Food Intake and Growth of Rats Fed a Low-Protein Diet.

Background: Low protein intake is associated with various negative health outcomes at any life stage. When diets do not contain sufficient protein, phosphorus availability is compromised because proteins are the major sources of phosphorus. However, whether mineral phosphorus supplementation mitigates this problem is unknown, to our knowledge. Objective: Our goal was to determine the impact of dietary phosphorus supplementation on food intake, weight gain, energy efficiency, body composition, blood metabolites, and liver histology in rats fed a low-protein diet for 9 wk. Methods: Forty-nine 6-wk-old male Sprague-Dawley rats were randomly allocated to 5 groups and consumed 5 isocaloric diets ad libitum that varied only in protein (egg white) and phosphorus concentrations for 9 wk. The control group received a 20% protein diet with 0.3% P (NP-0.3P). The 4 other groups were fed a low-protein (10%) diet with a phosphorus concentration of 0.015%, 0.056%, 0.1%, or 0.3% (LP-0.3P). The rats' weight, body and liver composition, and plasma biomarkers were then assessed. Results: The addition of phosphorus to the low-protein diet significantly increased food intake, weight gain, and energy efficiency, which were similar among the groups that received 0.3% P (LP-0.3P and NP-0.3P) regardless of dietary protein content. In addition, phosphorus supplementation of low-protein diets reduced plasma urea nitrogen and increased total body protein content (defatted). Changes in food intake and efficiency, body weight and composition, and plasma urea concentration were highly pronounced at a dietary phosphorus content <0.1%, which may represent a critical threshold. Conclusions: The addition of phosphorus to low-protein diets improved growth measures in rats, mainly as a result of enhanced energy efficiency. A dietary phosphorus concentration of 0.3% mitigated detrimental effects of low-protein diets on growth parameters.

BRAF and NRAS Mutations in Papillary Thyroid Carcinoma and Concordance in BRAF Mutations Between Primary and Corresponding Lymph Node Metastases.

Concordance between mutations in the primary papillary thyroid carcinoma (PTC) and the paired x lymph node metastasis may elucidate the potential role of molecular targeted therapy in advanced stages. BRAF and NRAS mutations in primary PTC (n = 253) with corresponding metastatic lymph node (n = 46) were analyzed utilizing StripAssays (ViennaLab Diagnostics). Statistical analysis was performed using (SPSS, Inc.), version 24.0 with a p-value of <0.05, and concordance via kappa agreement. BRAF mutation frequency in conventional PTC (cPTC): 56.8%, papillary thyroid microcarcinoma (PTMC): 36.5%, PTMC-FV: 2.7% and PTC-FV: 4.1%. NRAS mutation frequency in PTC-FV: 28.6%, PTMC: 28.6%, PTMC-FV: 23.8%, and cPTC: 19.0%. BRAF mutation correlation with older age in cPTC (42.6 versus 33.6) years (p < 0.001) was the only significant clinicopathologic parameter. BRAF mutations were concordant in the primary and its corresponding lymph node deposits in PTC with a kappa of 0.77 (p-value < 0.0001). BRAF mutations are predominant in cPTC and PTMC while NRAS mutations in PTC-FV. BRAF mutation is conserved in metastatic lymph node deposits, thus BRAF is an early mutational pathogenetic driver. Therefore, targeted therapy is potential in recurrent and advanced stage disease.

microRNA Expression in Ethnic Specific Early Stage Breast Cancer: an Integration and Comparative Analysis.

Breast cancer (BC) has a higher incidence in young Lebanese woman as compared to the West. We assessed the microRNA (miRNA) microarray profile of tissues derived from Lebanese patients with early BC and performed mRNA-miRNA integration analysis. 173 miRNAs were significantly dysregulated in 45 BC versus 17 normal adjacent breast tissues, including 74 with a fold change more than two of which 17 were never reported before in cancer. Integration analysis of mRNA-miRNA microarray data revealed a potential role of 51 dysregulated miRNA regulating 719 tumor suppressive or oncogenic mRNA associated with increased proliferation and decreased migration and invasion. We then performed a comparative miRNA microarray profile analysis of BC tissue between these 45 Lebanese and 197 matched American BC patients. Notably, Lebanese BC patients had 21 exclusively dysregulated miRNA (e.g. miR-31, 362-3p, and 663) and 4 miRNA with different expression manner compared to American patients (e.g. miR-1288-star and 324-3p). Some of these differences could reflect variation in patient age at diagnosis or ethnic variation affecting miRNA epigenetic regulation or sequence of miRNA precursors. Our data provide a basis for genetic/epigenetic investigations to explore the role of miRNA in early stage BC in young women, including ethnic specific differences.

Age dependent and cellular origin (stem versus progenitor) of a selected group of spontaneous brain tumors in humans.

The origin of spontaneous human brain tumors has been recently debated as originating from a stem rather than a progenitor cell. Based on the statistical distribution of a selected group of primary brain tumors, and on the clonality and field theory for cancer growth, we propose as plausible the contribution of progenitor cells in the origin of the most common brain tumors such as, pediatric, mixed (glial and neuronal), and the aggressive glioblastoma multiforme in adults. Operationally, stem cell is defined as having a renewal probability of p=1, a progenitor 0

Undifferentiated Nasopharyngeal Carcinoma Mimicking Hodgkin Lymphoma With CD30 Expression.

The presence of CD30-expressing Hodgkin-like cells with a background of inflammation and eosinophils in a young adolescent is usually diagnostic of classical Hodgkin lymphoma. Herein we present the case of a 12-year-old boy presenting with enlarged cervical lymph node characterized by the presence of Hodgkin-like cells expressing CD30 and EBV-LMP1 with a Hodgkin-like background. The Hodgkin-like cells were negative for CD15, CD20, CD45, and Pax-5. The tumor cells, however, expressed several cytokeratins, confirming the diagnosis of an undifferentiated carcinoma nasopharyngeal type. This case highlights the importance of possessing a high index of suspicion when encountering lymph nodes with Hodgkin-like cells and a Hodgkin-like background, even with CD30 expression, as the differential can include undifferentiated carcinoma nasopharyngeal type.

Mesothelial Cells Within Vascular Transformation of Mediastinal Lymph Node Sinuses: An Unusual Benign Collision Mimicking Colliding Malignancies.

Vascular transformation of lymph node sinuses represents a rare benign entity mimicking malignant counterparts such as nodal Kaposi sarcoma. The presence of mildly atypical benign mesothelial cells within nodal sinuses raises the possibility of metastatic malignancy. Herein, a rare case of vascular transformation of lymph node sinuses with reactive sinusoidal mesothelial cells is outlined as a unique benign pathology and a potential mimicker of a malignant collision tumor.

Activating BRAF Mutations Detected in Mixed Hürthle Cell Carcinoma and Multifocal Papillary Carcinoma of the Thyroid Gland: Report of an Unusual Case and Review of the Literature.

Despite the increase in the incidence of thyroid carcinomas, the occurrence of collision tumors in the thyroid remains a rare event. We present the case of a 69-year-old female who presented to the emergency department with a chief complaint of painful neck swelling. Imaging revealed a large right hemithyroid mass and a left hemithyroid nodule. Fine needle aspiration of the lesions and subsequent total thyroidectomy revealed a Hürthle cell carcinoma in the right lobe and bilateral multicentric papillary carcinoma foci, including 2 foci with a classical pattern and 1 encapsulated follicular variant in the isthmus. BRAF gene mutation analysis revealed V600E gene mutation in the classical variants of papillary carcinoma and in the Hürthle cell carcinoma. The focus of follicular variant of papillary carcinoma in the isthmus and a sample from normal thyroid tissue did not harbor BRAF mutations. This case is remarkable in being an unusual report of a follicular Hürthle cell carcinoma harboring the BRAF V600E mutation and occurring in collision with multifocal papillary carcinoma. Documentation of such cases is important as it helps better understand the pathogenesis, clinical behavior, and radiologic findings of such rare lesions and to determine the optimal treatment modalities.

Programmed Death-Ligand 1 Expression in Muscle-Invasive Bladder Cancer Cystectomy Specimens and Lymph Node Metastasis: A Reliable Treatment Selection Biomarker?

BACKGROUND: The programmed death-1 (PD-1) pathway negatively regulates T-cell activation and has an important role in regulating antitumor host immunity. Monoclonal antibodies directed against PD-1 or the PD-1 ligand (PD-L1) have shown activity in several tumor types with preliminary data suggesting a relationship between PD-L1 expression and response. The aim of this study was to establish the frequency of PD-L1 expression in muscle-invasive bladder cancer and associated lymph node metastasis using immunohistochemistry and to investigate the feasibility of using PD-L1 expression as a biomarker to select patients for PD-1-directed therapy. PATIENTS AND METHODS: Cases of radical cystectomy for muscle-invasive bladder cancer with no exposure to previous chemotherapy were identified and representative slides from archived paraffin-embedded blocks stained with anti-PD-L1 antibody (5H1 clone) were identified. PD-L1 positivity was defined by a 5% expression threshold. RESULTS: Fifty-two radical cystectomy specimens were reviewed. PD-L1 was overexpressed in the tumor cells of 5/52 (9.6%) of cystectomy specimens in this cohort with 17/52 (32.7%) of cases showing PD-L1 overexpression in tumor-infiltrating immune cells. Discordance was observed between PD-L1 expression in lymph node metastasis and the primary tumor. CONCLUSION: Standard assays for PD-L1 expression have yet to be established. The observation of discordance between PD-L1 expression in metastatic sites and primary tumors suggests that prospective biomarker studies should aim to acquire material immediately before treatment initiation rather than archived tissue from resected specimens that might not reflect the current immune-active microenvironment.