Characteristics and distinct prognostic determinants of individuals with hepatosplenic T-cell lymphoma over the past two decades.

BACKGROUND: Hepatosplenic T-cell lymphoma (HSTCL) is a rare and aggressive peripheral T-cell lymphoma with historically dismal outcomes, representing less than one percent of non-Hodgkin lymphomas. Given its rarity, the true incidence of HSTCL is unknown and most data have been extrapolated through case reports. To the best of our knowledge, the largest and most up to date study addressing the epidemiology and outcomes of patients with HSTCL in the United States covered a period from 1996 to 2014, with a sample size of 122 patients. AIM: To paint the most updated epidemiological picture of HSTCL. METHODS: A total of 186 patients diagnosed with HSTCL, between 2000 and 2017, were ultimately enrolled in our study by retrieving data from the Surveillance, Epidemiology, and End Results database. We analyzed demographics, clinical characteristics, and overall mortality (OM) as well as cancer-specific mortality (CSM) of HSTCL. Variables with a P value < 0.01 in the univariate Cox regression were incorporated into the multivariate Cox model to determine the independent prognostic factors, with a hazard ratio of greater than 1 representing adverse prognostic factors. RESULTS: Male gender was the most represented. HSTCL was most common in middle-aged patients (40-59) and less common in the elderly (80+). Non-Hispanic whites (60.75%) and non-Hispanic blacks (20.97%) were the most represented racial groups. Univariate Cox proportional hazard regression analysis of factors influencing all-cause mortality showed a higher OM among non-Hispanic black patients. CSM was also higher among non-Hispanic blacks and patients with distant metastasis. Multivariate Cox proportional hazard regression analysis of factors affecting CSM revealed higher mortality in patients aged 80 or older and non-Hispanic blacks. CONCLUSION: Overall, the outlook for this rare malignancy is very grim. In this retrospective cohort study of the United States population, non-Hispanic blacks and the elderly had a higher CSM. This data highlights the need for larger prospective studies to investigate factors associated with worse prognosis in one ethnic group, such as treatment delays, which have been shown to increase mortality in this racial/ethnic group for other cancers.

Ventricular Tachycardia in Patients With Takotsubo Cardiomyopathy: Prevalence, Predictors, and Associated In-Hospital Adverse Events.

Introduction  The purpose of this study was to determine the prevalence of ventricular tachycardia (VT) among patients admitted with takotsubo cardiomyopathy (TCM) as well as to analyze the predictors of VT and the predictors of mortality among patients admitted with TCM. Methods Data were obtained from the National Inpatient Sample (NIS) database from January 2016 to December 2019. Patients with a primary diagnosis of TCM were selected using ICD-10 code I51.81. Subsequently, the study population was divided into patients who developed VT vs. patients who did not develop this complication. We then used multivariate logistic regression to assess the predictors of VT in our patient cohort as well as the predictors of mortality among patients admitted with TCM. Results  Of 40114 patients with TCM, 1923 developed VT (4.8%) during their hospital stay. Predictors of VT include atrial fibrillation (AF) (adjusted odds ratio (aOR): 1.592; 95% confidence interval (CI): 0.00-1.424; p=0.001), congestive heart failure (aOR: 1.451; 95% CI: 1.307-1.610; p=0.001), coagulopathy (aOR: 1.436; 95% CI: 1.150-1.793; p=0.001), and patients who self-identify in the race category as Other (aOR: 1.427; 95% CI: 1.086-1.875; p=0.011). Female sex was found to be protective against VT (aOR: 0.587; 95% CI: 0.526-0.656; p=0.001). Predictors of mortality among patients admitted with TCM include, among other factors, age (aOR: 1.014; 95% CI: 1.011-1.018; p=0.001), Asian or Pacific Islander race (aOR: 1.533; 95% CI: 1.197-1.964; p=0.001), Black race (aOR: 1.242; 95% CI: 1.062-1.452; p=0.007), VT (aOR: 1.754; 95% CI: 1.505-2.045; p=0.001), and AF (aOR: 1.441; 95% CI: 1.301-1.597; p=0.001). Some comorbidities that were protective against mortality in TCM include tobacco use disorder (aOR: 0.558; 95% CI: 0.255-0.925; p=0.028) and obstructive sleep apnea (aOR: 0.803; 95% CI: 0.651-0.990; p=0.028). The female sex was found to be protective against mortality (aOR: 0.532; 95% CI: 0.480-0.590; p=0.001).  Conclusion  In a large cohort of women admitted with TCM, we found the prevalence of VT to be 4.8%. Predictors of VT included conditions such as AF and congestive heart failure. The female sex was found to be protective against VT and protective against mortality among patients admitted with TCM.

Factors Affecting Survival Outcomes in Neuroendocrine Tumor of the Appendix over the Past Two Decades.

BACKGROUND: Appendiceal neuroendocrine tumors (NETs) rank as the third most frequent neoplasm affecting the appendix, originating from enterochromaffin cells. This study aims to evaluate the influence of various prognostic factors on the mortality rates of patients diagnosed with NETs of the appendix. METHODS: Conducted retrospectively, the study involved 3346 patients, utilizing data sourced from the Surveillance, Epidemiology, and End Results (SEER) database. Our analysis centered on investigating demographic characteristics, clinical features, overall mortality (OM), and cancer-specific mortality (CSM) among the cohort. Variables showing a p-value < 0.1 in the univariate Cox regression were incorporated into the multivariate Cox regression analysis. A Hazard Ratio (HR) > 1 indicated an unfavorable prognosis. RESULTS: In the multivariate analysis, higher OM and CSM were observed in males, older age groups, tumors with distant metastasis, poorly differentiated tumors, and those who underwent chemotherapy. Non-Hispanic Black individuals showed elevated mortality rates. CONCLUSION: Delayed diagnosis may contribute to the increased mortality in this community. Improved access to healthcare and treatment is crucial for addressing these disparities. Larger prospective studies are needed to pinpoint the underlying causes of elevated mortality in non-Hispanic Black populations, and randomized controlled trials (RCTs) are warranted to evaluate therapies for advanced-stage appendix NETs.

Oral mucosa and cutaneous manifestations of psoriasis in an older patient: A case report.

BACKGROUND: Psoriasis is a common cutaneous disease; however, information about psoriasis-related oral mucosal lesions is scarce in the literature. CASE DESCRIPTION: We report a case of a 73-year-old male patient with cutaneous and oral palatal alterations. An incisional biopsy of these lesions revealed psoriasis. CONCLUSION: The current case highlights the importance of a systematic examination of the oral cavity in psoriasis patients for the appropriate diagnosis and management on the control of these lesions.

Essential Role of CgErg6p in Maintaining Oxidative Stress Tolerance and Iron Homeostasis in Candida glabrata.

The human pathogenic fungus Candida glabrata is the second leading cause of candidemia, a life-threatening invasive mycosis. Clinical outcomes are complicated by reduced susceptibility of C. glabrata to azoles together with its ability to evolve stable resistance to both azoles and echinocandins following drug exposure. Compared to other Candida spp., C. glabrata displays robust oxidative stress resistance. In this study, we investigated the impact of CgERG6 gene deletion on the oxidative stress response in C. glabrata. CgERG6 gene encodes sterol-24-C-methyltransferase, which is involved in the final steps of ergosterol biosynthesis. Our previous results showed that the Cgerg6Δ mutant has a lower ergosterol content in its membranes. Here, we show that the Cgerg6Δ mutant displays increased susceptibility to oxidative stress inducing agents, such as menadione, hydrogen peroxide and diamide, accompanied with increased intracellular ROS production. The Cgerg6Δ mutant is not able to tolerate higher concentrations of iron in the growth media. We observed increased expression of transcription factors, CgYap1p, CgMsn4p and CgYap5p, together with increased expression of catalase encoding the CgCTA1 gene and vacuolar iron transporter CgCCC1 in the Cgerg6Δ mutant cells. However, it seems that the CgERG6 gene deletion does not influence the function of mitochondria.

Catechin potentiates the antifungal effect of miconazole in Candida glabrata.

The rising number of invasive fungal infections caused by drug-resistant Candida strains is one of the greatest challenges for the development of novel antifungal strategies. The scarcity of available antifungals has drawn attention to the potential of natural products as antifungals and in combinational therapies. One of these is catechins-polyphenolic compounds-flavanols, found in a variety of plants. In this work, we evaluated the changes in the susceptibility of Candida glabrata strain characterized at the laboratory level and clinical isolates using the combination of catechin and antifungal azoles. Catechin alone had no antifungal activity within the concentration range tested. Its use in combination with miconazole resulted in complete inhibition of growth in the sensitive C. glabrata isolate and a significant growth reduction in the azole resistant C. glabrata clinical isolate. Simultaneous use of catechin and miconazole leads to increased intracellular ROS generation. The enhanced susceptibility of C. glabrata clinical isolates to miconazole by catechin was accompanied with the intracellular accumulation of ROS and changes in the plasma membrane permeability, as measured using fluorescence anisotropy, affecting the function of plasma membrane proteins.

Health Maintenance and Preventative Care in Inflammatory Bowel Disease: A Systematic Review of the Overall Quality of Societal Recommendations.

BACKGROUND AIMS: Preventative care plays an important role in maintaining health in patients with inflammatory bowel disease (IBD). We aimed to assess the overall quality, strength, and transparency of conflicts among guidelines on preventative care in IBD. METHODS: A systematic literature search was performed in multiple databases to identify all guidelines pertaining to preventative care in IBD in April 2021. All guidelines were reviewed for the transparency of conflicts of interest and funding, recommendation quality and strength, external guideline review, patient voice inclusion, and plan for update-as per Institute of Medicine standards. In addition, recommendations and their quality were compared between societies. RESULTS: Fifteen distinct societies and a total of 89 recommendations were included. Not all guidelines provided recommendations on the key aspects of preventative care in IBD-such as vaccinations, cancer prevention, stress reduction, and diet/exercise. Sixty-seven percent of guidelines reported on conflicts of interest, 20% underwent external review, and 27% included patient representation. In all, 6.7%, 21.3%, and 71.9% of recommendations were based on high, moderate, and low-quality evidence, respectively. Twenty-seven percent, 23.6%, and 49.4% of recommendations were strong, weak/conditional, and did not provide a strength, respectively. The proportion of high-quality evidence ( P =0.28) and strong recommendations ( P =0.41) did not significantly differ across societies. CONCLUSIONS: Many guidelines do not provide recommendations on key aspects of preventative care in IBD. As over 70% of recommendations are based on low-quality evidence, further studies on preventative care in IBD are warranted to improve the overall quality of evidence.

Perfil clínico dos pacientes internados por Covid-19 na unidade de terapia intensiva / Clinical profile of patients hospitalized for Covid-19 in the intensive care unit

Objetivo: identificar o perfil clínico dos pacientes internados por COVID-19 na Unidade de Terapia Intensiva (UTI) de um hospital privado. Métodos: trata-se deum estudo de caráter descritivo, documental, retrospectivo, de corte transversal e análise quantitativa, conduzido em um hospital, no município de Montes Claros, MG, por meio da análise de prontuários de 142 pacientes da UTI com diagnóstico de COVID-19 no período de janeiro de 2020 a abril de 2021. Resultados: dos 142 indivíduos, a média de idadefoi de 64,1 anos, com 58,5% do sexo masculino. Das comorbidades prévias, as que tiveram maior prevalência foram a hipertensão arterial sistêmica com 26,8% e diabetes mellitus com 9,2%. Destes, 133 indivíduos utilizaram ventilação mecânica, com a prevalência de 47,9% no modo ventilação com volume controlado. O tempo médio de internação foi de 6 dias, sendo que 93,7% dos indivíduos foram a óbito, 4,9% receberam alta e 1,4% transferidos para outro hospital. Conclusão: evidenciou-se predominância do sexo masculino, com média de idade de 64,1 anos, o modo ventilatório mais utilizado foi o controlado o volume, com tempo de uso médio de uso 7,9 dias, ou seja, pouco tempo, fato que pode ser justificado pelo alto índice de óbitos na amostra estudada.

Objective: to identify the clinical profile of patients hospitalized for COVID-19 in the Intensive Care Unit (ICU) of a private hospital. Methods: this is a descriptive, documentary, retrospective, cross-sectional study with quantitative analysis conducted in a hospital in the city of Montes Claros, MG, through the analysis of medical records of 142 ICU patients diagnosed with COVID-19 from January 2020 to April 2021. Results: of the 142 individuals, the mean age was 64.1 years, with 58.5% male. Of the previous comorbidities, those with the highest prevalence were systemic arterial hypertension at 26.8% and diabetes mellitus at 9.2%. Of these, 133 individuals used mechanical ventilation, with a prevalence of 47.9% using volume-controlled ventilation. The average length of stay was 6 days, with 93.7% of the individuals dying, 4.9% being discharged, and 1.4% being transferred to another hospital. Conclusion: there was a predominance of males, with an average age of 64.1 years, the most used ventilatory mode was volume-controlled, with an average use time of 7.9 days, that is, a short time, a fact that can be justified by the high rate of deaths in the studied sample.

Co-targeting CDK2 and CDK4/6 overcomes resistance to aromatase and CDK4/6 inhibitors in ER+ breast cancer.

Resistance to aromatase inhibitor (AI) treatment and combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy (ET) are crucial clinical challenges in treating estrogen receptor-positive (ER+) breast cancer. Understanding the resistance mechanisms and identifying reliable predictive biomarkers and novel treatment combinations to overcome resistance are urgently needed. Herein, we show that upregulation of CDK6, p-CDK2, and/or cyclin E1 is associated with adaptation and resistance to AI-monotherapy and combined CDK4/6i and ET in ER+ advanced breast cancer. Importantly, co-targeting CDK2 and CDK4/6 with ET synergistically impairs cellular growth, induces cell cycle arrest and apoptosis, and delays progression in AI-resistant and combined CDK4/6i and fulvestrant-resistant cell models and in an AI-resistant autocrine breast tumor in a postmenopausal xenograft model. Analysis of CDK6, p-CDK2, and/or cyclin E1 expression as a combined biomarker in metastatic lesions of ER+ advanced breast cancer patients treated with AI-monotherapy or combined CDK4/6i and ET revealed a correlation between high biomarker expression and shorter progression-free survival (PFS), and the biomarker combination was an independent prognostic factor in both patients cohorts. Our study supports the clinical development of therapeutic strategies co-targeting ER, CDK4/6 and CDK2 following progression on AI-monotherapy or combined CDK4/6i and ET to improve survival of patients exhibiting high tumor levels of CDK6, p-CDK2, and/or cyclin E1.

Generalized verrucosis in GATA2 deficiency successfully treated with systemic acitretin and trichloroacetic acid.

Generalized verrucosis is a clinical manifestation of human papillomavirus infection. Patients with generalized verrucosis present with over 20 verrucae distributed over various anatomical sites. The disorder occurs in association with several genetic syndromes with immunodeficiency, including GATA2 deficiency. We report a 12-year-old boy with GATA2 deficiency and generalized verrucosis that worsened after cyclosporine use following bone marrow transplant. Systemic treatment with acitretin and topical application of trichloroacetic acid, likely along with immune reconstitution, led to complete remission.

MCM3 upregulation confers endocrine resistance in breast cancer and is a predictive marker of diminished tamoxifen benefit.

Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER+ breast cancer. We discovered that ER+ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in the cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation of cell cycle regulators, including p53(Ser315,33), CHK1(Ser317), and cdc25b(Ser323), suggesting that the interaction of MCM3 with cell cycle proteins is an important mechanism of overcoming replicative stress and anti-proliferative effects of endocrine treatments. Interestingly, the MCM3 levels did not affect the efficacy of growth inhibitory by CDK4/6 inhibitors. Evaluation of MCM3 levels in primary tumors from four independent cohorts of breast cancer patients receiving adjuvant tamoxifen mono-therapy or no adjuvant treatment, including the Stockholm tamoxifen (STO-3) trial, showed MCM3 to be an independent prognostic marker adding information beyond Ki67. In addition, MCM3 was shown to be a predictive marker of response to endocrine treatment. Our study reveals a coordinated signaling network centered around MCM3 that limits response to endocrine therapy in ER+ breast cancer and identifies MCM3 as a clinically useful prognostic and predictive biomarker that allows personalized treatment of ER+ breast cancer patients.

MicroRNA-155-5p Plays a Critical Role in Transient Leukemia of Down Syndrome by Targeting Tumor Necrosis Factor Receptor Superfamily Members.

BACKGROUND/AIMS: Down syndrome associated disorders are caused by a complex genetic context where trisomy 21 is a central component in relation to other changes involving epigenetic regulators and signaling molecules. This unique genetic context is responsible for the predisposition of people with Down syndrome to acute leukemia. Although, the research in this field has discovered some important pathogenic keys, the exact mechanism of this predisposition is not known. METHODS: In this study we applied functional enrichment analysis to evaluate the interactions between genes localized on chromosome 21, genes already identify as having a key role in acute leukemia of Down syndrome, miRNAs and signaling pathways implicated in cancer and cell development and found that miR-155 has a high impact in genes present on chromosome 21. Forward, we performed next generation sequencing on DNA samples from a cohort of patients diagnosed with acute leukemia of Down syndrome and in vitro functional assay using a CMK-86 cell line, transfected with either mimic or inhibitor of the microRNA-155-5p. RESULTS: Our results show that the epigenetic alteration of the TNF superfamily receptors in Down syndrome, which can be correlated to microRNA-155-5p aberrant activity, may play an important role in cell signaling and thus be linked to acute myeloid leukemia. CONCLUSION: Some genes, already shown to be mutated in AML-DS, are potential targets for miR-155. Our results show that the epigenetic alteration of the TNF superfamily receptors in Down syndrome may play an important role in cell signaling and thus be linked to acute myeloid leukemia.

Tumor Initiation Capacity and Therapy Resistance Are Differential Features of EMT-Related Subpopulations in the NSCLC Cell Line A549.

Cell lines are essential tools to standardize and compare experimental findings in basic and translational cancer research. The current dogma states that cancer stem cells feature an increased tumor initiation capacity and are also chemoresistant. Here, we identified and comprehensively characterized three morphologically distinct cellular subtypes in the non-small cell lung cancer cell line A549 and challenge the current cancer stem cell dogma. Subtype-specific cellular morphology is maintained during short-term culturing, resulting in the formation of holoclonal, meroclonal, and paraclonal colonies. A549 holoclone cells were characterized by an epithelial and stem-like phenotype, paraclone cells featured a mesenchymal phenotype, whereas meroclone cells were phenotypically intermediate. Cell-surface marker expression of subpopulations changed over time, indicating an active epithelial-to-mesenchymal transition (EMT), in vitro and in vivo. EMT has been associated with the overexpression of the immunomodulators PD-L1 and PD-L2, which were 37- and 235-fold overexpressed in para- versus holoclone cells, respectively. We found that DNA methylation is involved in epigenetic regulation of marker expression. Holoclone cells were extremely sensitive to cisplatin and radiotherapy in vitro, whereas paraclone cells were highly resistant. However, inhibition of the receptor tyrosine kinase AXL, whose expression is associated with an EMT, specifically targeted the otherwise highly resistant paraclone cells. Xenograft tumor formation capacity was 24- and 269-fold higher in holo- than mero- and paraclone cells, respectively. Our results show that A549 subpopulations might serve as a unique system to explore the network of stemness, cellular plasticity, tumor initiation capacity, invasive and metastatic potential, and chemo/radiotherapy resistance.

SNAI2 upregulation is associated with an aggressive phenotype in fulvestrant-resistant breast cancer cells and is an indicator of poor response to endocrine therapy in estrogen receptor-positive metastatic breast cancer.

BACKGROUND: Endocrine resistance in estrogen receptor-positive (ER+) breast cancer is a major clinical problem and is associated with accelerated cancer cell growth, increased motility and acquisition of mesenchymal characteristics. However, the specific molecules and pathways involved in these altered features remain to be detailed, and may be promising therapeutic targets to overcome endocrine resistance. METHODS: In the present study, we evaluated altered expression of epithelial-mesenchymal transition (EMT) regulators in ER+ breast cancer cell models of tamoxifen or fulvestrant resistance, by gene expression profiling. We investigated the specific role of increased SNAI2 expression in fulvestrant-resistant cells by gene knockdown and treatment with a SNAIL-p53 binding inhibitor, and evaluated the effect on cell growth, migration and expression of EMT markers. Furthermore, we evaluated SNAI2 expression by immunohistochemical analysis in metastatic samples from two cohorts of patients with breast cancer treated with endocrine therapy in the advanced setting. RESULTS: SNAI2 was found to be significantly upregulated in all endocrine-resistant cells compared to parental cell lines, while no changes were observed in the expression of other EMT-associated transcription factors. SNAI2 knockdown with specific small interfering RNA (siRNA) converted the mesenchymal-like fulvestrant-resistant cells into an epithelial-like phenotype and reduced cell motility. Furthermore, inhibition of SNAI2 with specific siRNA or a SNAIL-p53 binding inhibitor reduced growth of cells resistant to fulvestrant treatment. Clinical evaluation of SNAI2 expression in two independent cohorts of patients with ER+ metastatic breast cancer treated with endocrine therapy in the advanced setting (N = 86 and N = 67) showed that high SNAI2 expression in the metastasis correlated significantly with shorter progression-free survival on endocrine treatment (p = 0.0003 and p = 0.004). CONCLUSIONS: Our results suggest that SNAI2 is a key regulator of the aggressive phenotype observed in endocrine-resistant breast cancer cells, an independent prognostic biomarker in ER+ advanced breast cancer treated with endocrine therapy, and may be a promising therapeutic target in combination with endocrine therapies in ER+ metastatic breast cancer exhibiting high SNAI2 levels.

Multiscale approach to the activation and phosphotransfer mechanism of CpxA histidine kinase reveals a tight coupling between conformational and chemical steps.

Sensor histidine kinases (SHKs) are an integral component of the molecular machinery that permits bacteria to adapt to widely changing environmental conditions. CpxA, an extensively studied SHK, is a multidomain homodimeric protein with each subunit consisting of a periplasmic sensor domain, a transmembrane domain, a signal-transducing HAMP domain, a dimerization and histidine phospho-acceptor sub-domain (DHp) and a catalytic and ATP-binding subdomain (CA). The key activation event involves the rearrangement of the HAMP-DHp helical core and translation of the CA towards the acceptor histidine, which presumably results in an autokinase-competent complex. In the present work we integrate coarse-grained, all-atom, and hybrid QM-MM computer simulations to probe the large-scale conformational reorganization that takes place from the inactive to the autokinase-competent state (conformational step), and evaluate its relation to the autokinase reaction itself (chemical step). Our results highlight a tight coupling between conformational and chemical steps, underscoring the advantage of CA walking along the DHp core, to favor a reactive tautomeric state of the phospho-acceptor histidine. The results not only represent an example of multiscale modelling, but also show how protein dynamics can promote catalysis.

Integrative analysis of miRNA and gene expression reveals regulatory networks in tamoxifen-resistant breast cancer.

Tamoxifen is an effective anti-estrogen treatment for patients with estrogen receptor-positive (ER+) breast cancer, however, tamoxifen resistance is frequently observed. To elucidate the underlying molecular mechanisms of tamoxifen resistance, we performed a systematic analysis of miRNA-mediated gene regulation in three clinically-relevant tamoxifen-resistant breast cancer cell lines (TamRs) compared to their parental tamoxifen-sensitive cell line. Alterations in the expression of 131 miRNAs in tamoxifen-resistant vs. parental cell lines were identified, 22 of which were common to all TamRs using both sequencing and LNA-based quantitative PCR technologies. Although the target genes affected by the altered miRNA in the three TamRs differed, good agreement in terms of affected molecular pathways was observed. Moreover, we found evidence of miRNA-mediated regulation of ESR1, PGR1, FOXM1 and 14-3-3 family genes. Integrating the inferred miRNA-target relationships, we investigated the functional importance of 2 central genes, SNAI2 and FYN, which showed increased expression in TamR cells, while their corresponding regulatory miRNA were downregulated. Using specific chemical inhibitors and siRNA-mediated gene knockdown, we showed that both SNAI2 and FYN significantly affect the growth of TamR cell lines. Finally, we show that a combination of 2 miRNAs (miR-190b and miR-516a-5p) exhibiting altered expression in TamR cell lines were predictive of treatment outcome in a cohort of ER+ breast cancer patients receiving adjuvant tamoxifen mono-therapy. Our results provide new insight into the molecular mechanisms of tamoxifen resistance and may form the basis for future medical intervention for the large number of women with tamoxifen-resistant ER+ breast cancer.

High CDK6 Protects Cells from Fulvestrant-Mediated Apoptosis and is a Predictor of Resistance to Fulvestrant in Estrogen Receptor-Positive Metastatic Breast Cancer.

PURPOSE: Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer remains a major clinical problem. Recently, the CDK4/6 inhibitor palbociclib combined with letrozole or fulvestrant was approved for treatment of ER+ advanced breast cancer. However, the role of CDK4/6 in endocrine resistance and their potential as predictive biomarkers of endocrine treatment response remains undefined. EXPERIMENTAL DESIGN: We investigated the specific role of increased CDK6 expression in fulvestrant-resistant cells by gene knockdown and treatment with palbociclib, and evaluated the effect in cell proliferation, apoptosis, and kinase activity. Furthermore, we evaluated CDK6 expression in metastatic samples from breast cancer patients treated or not with fulvestrant. RESULTS: We found increased expression of CDK6 in two fulvestrant-resistant cell models versus sensitive cells. Reduction of CDK6 expression impaired fulvestrant-resistant cell growth and induced apoptosis. Treatment with palbociclib resensitized fulvestrant-resistant cells to fulvestrant through alteration of retinoblastoma protein phosphorylation. High CDK6 levels in metastatic samples from two independent cohorts of breast cancer patients treated with fulvestrant (N = 45 and 46) correlated significantly with shorter progression-free survival (PFS) on fulvestrant treatment (P = 0.0006 and 0.018), whereas no association was observed in patients receiving other first- or second-/third-line endocrine treatments (N = 68, P = 0.135 and 0.511, respectively). CONCLUSIONS: Our results indicate that upregulation of CDK6 may be an important mechanism in overcoming fulvestrant-mediated growth inhibition in breast cancer cells. Patients with advanced ER+ breast cancer exhibiting high CDK6 expression in the metastatic lesions show shorter PFS upon fulvestrant treatment and thus may benefit from the addition of CDK4/6 inhibitors in their therapeutic regimens. Clin Cancer Res; 22(22); 5514-26. ©2016 AACR.

Gene expression alterations associated with outcome in aromatase inhibitor-treated ER+ early-stage breast cancer patients.

Aromatase inhibitors (AI), either alone or together with chemotherapy, have become the standard adjuvant treatment for postmenopausal, estrogen receptor-positive (ER+) breast cancer. Although AIs improve overall survival, resistance is still a major clinical problem, thus additional biomarkers predictive of outcome of ER+ breast cancer patients treated with AIs are needed. Global gene expression analysis was performed on ER+ primary breast cancers from patients treated with adjuvant AI monotherapy; half experienced recurrence (median follow-up 6.7 years). Gene expression alterations were validated by qRT-PCR, and functional studies evaluating the effect of siRNA-mediated gene knockdown on cell growth were performed. Twenty-six genes, including TFF3, DACH1, RGS5, and GHR, were shown to exhibit altered expression in tumors from patients with recurrence versus non-recurrent (fold change ≥1.5, p < 0.05), and the gene expression alterations were confirmed using qRT-PCR. Ten of these 26 genes could be linked in a network associated with cellular proliferation, growth, and development. TFF3, which encodes for trefoil factor 3 and is an estrogen-responsive oncogene shown to play a functional role in tamoxifen resistance and metastasis of ER+ breast cancer, was also shown to be upregulated in an AI-resistant cell line model, and reduction of TFF3 levels using TFF3-specific siRNAs decreased the growth of both the AI-resistant and -sensitive parental cell lines. Moreover, overexpression of TFF3 in parental AI-sensitive MCF-7/S0.5 cells resulted in reduced sensitivity to the AI exemestane, whereas TFF3 overexpression had no effect on growth in the absence of exemestane, indicating that TFF3 mediates growth and survival signals that abrogate the growth inhibitory effect of exemestane. We identified a panel of 26 genes exhibiting altered expression associated with disease recurrence in patients treated with adjuvant AI monotherapy, including TFF3, which was shown to exhibit a growth- and survival-promoting effect in the context of AI treatment.