PARP-1 selectively impairs KRAS-driven phenotypic and molecular features in intrahepatic cholangiocarcinoma.

OBJECTIVE: Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer with limited therapeutic options. KRAS mutations are among the most abundant genetic alterations in iCCA associated with poor clinical outcome and treatment response. Recent findings indicate that Poly(ADP-ribose)polymerase1 (PARP-1) is implicated in KRAS-driven cancers, but its exact role in cholangiocarcinogenesis remains undefined. DESIGN: PARP-1 inhibition was performed in patient-derived and established iCCA cells using RNAi, CRISPR/Cas9 and pharmacological inhibition in KRAS-mutant, non-mutant cells. In addition, Parp-1 knockout mice were combined with iCCA induction by hydrodynamic tail vein injection to evaluate an impact on phenotypic and molecular features of Kras-driven and Kras-wildtype iCCA. Clinical implications were confirmed in authentic human iCCA. RESULTS: PARP-1 was significantly enhanced in KRAS-mutant human iCCA. PARP-1-based interventions preferentially impaired cell viability and tumourigenicity in human KRAS-mutant cell lines. Consistently, loss of Parp-1 provoked distinct phenotype in Kras/Tp53-induced versus Akt/Nicd-induced iCCA and abolished Kras-dependent cholangiocarcinogenesis. Transcriptome analyses confirmed preferential impairment of DNA damage response pathways and replicative stress response mediated by CHK1. Consistently, inhibition of CHK1 effectively reversed PARP-1 mediated effects. Finally, Parp-1 depletion induced molecular switch of KRAS-mutant iCCA recapitulating good prognostic human iCCA patients. CONCLUSION: Our findings identify the novel prognostic and therapeutic role of PARP-1 in iCCA patients with activation of oncogenic KRAS signalling.

Inhibition of PRMT5-mediated regulation of DKK1 sensitizes colorectal cancer cells to chemotherapy.

The Dickkopf family proteins (DKKs) are strong Wnt signaling antagonists that play a significant role in colorectal cancer (CRC) development and progression. Recent work has shown that DKKs, mainly DKK1, are associated with the induction of chemoresistance in CRC and that DKK1 expression in cancer cells correlates with that of protein arginine N-methyltransferase 5 (PRMT5). This points to the presence of a regulatory loop between DKK1 and PRMT5. Herein, we addressed the question of whether PRMT5 contributes to DKK1 expression in CRC and hence CRC chemoresistance. Both in silico and in vitro approaches were used to explore the relationship between PRMT5 and different DKK members. Our data demonstrated that DKK1 expression is significantly upregulated in CRC clinical samples, KRAS-mutated CRC in particular and that the levels of DKK1 positively correlate with PRMT5 activation. Chromatin immunoprecipitation (ChIP) data indicated a possible epigenetic role of PRMT5 in regulating DKK1, possibly through the symmetric dimethylation of H3R8. Knockdown of DKK1 or treatment with the PRMT5 inhibitor CMP5 in combination with doxorubicin yielded a synergistic anti-tumor effect in KRAS mutant, but not KRAS wild-type, CRC cells. These findings suggest that PRMT5 regulates DKK1 expression in CRC and that inhibition of PRMT5 modulates DKK1 expression in such a way that reduces CRC cell growth.

Deletion of Cd44 Inhibits Metastasis Formation of Liver Cancer in Nf2-Mutant Mice.

Primary liver cancer is the third leading cause of cancer-related death worldwide. An increasing body of evidence suggests that the Hippo tumor suppressor pathway plays a critical role in restricting cell proliferation and determining cell fate during physiological and pathological processes in the liver. Merlin (Moesin-Ezrin-Radixin-like protein) encoded by the NF2 (neurofibromatosis type 2) gene is an upstream regulator of the Hippo signaling pathway. Targeting of Merlin to the plasma membrane seems to be crucial for its major tumor-suppressive functions; this is facilitated by interactions with membrane-associated proteins, including CD44 (cluster of differentiation 44). Mutations within the CD44-binding domain of Merlin have been reported in many human cancers. This study evaluated the relative contribution of CD44- and Merlin-dependent processes to the development and progression of liver tumors. To this end, mice with a liver-specific deletion of the Nf2 gene were crossed with Cd44-knockout mice and subjected to extensive histological, biochemical and molecular analyses. In addition, cells were isolated from mutant livers and analyzed by in vitro assays. Deletion of Nf2 in the liver led to substantial liver enlargement and generation of hepatocellular carcinomas (HCCs), intrahepatic cholangiocarcinomas (iCCAs), as well as mixed hepatocellular cholangiocarcinomas. Whilst deletion of Cd44 had no influence on liver size or primary liver tumor development, it significantly inhibited metastasis formation in Nf2-mutant mice. CD44 upregulates expression of integrin ß2 and promotes transendothelial migration of liver cancer cells, which may facilitate metastatic spreading. Overall, our results suggest that CD44 may be a promising target for intervening with metastatic spreading of liver cancer.

Immediate Effects of Mindfulness Meditation on the Voice.

OBJECTIVES: The benefits of mindfulness meditation are well documented. This study evaluated the immediate effects of mindfulness meditation (MM) on the voice and voice user. STUDY DESIGN: Prospective experimental study. METHODS: Participants: 19 vocally healthy (VH) individuals, and 26 individuals with common voice disorders (CVD; benign lesions and hyperfunctional muscle tension) deemed stimulable for voice therapy. Exclusionary criteria: prior training or regular meditation practice. Participants recorded speech samples before and after a 11.5-minute prerecorded session of MM. PRIMARY OUTCOMES: phonatory aerodynamics and participants' self-reported experience of voice. SECONDARY OUTCOMES: self-reported anxiety, vocal acoustics, speech breathing patterns, and auditory-perceptual outcomes. Baseline self-reported measures of voice (Voice Handicap Index-10 - VHI-10), breathing (Dyspnea Index - DI), stress (Perceived Stress Scale - PSS), and trait mindfulness (Cognitive and Mindfulness Scale - Revised, CAMS-R, Five Facet Mindfulness Questionnaire - FFMQ) were compared between groups. RESULTS: At baseline, CVD had significantly higher VHI-10 (P< 0.001) and DI (P= 0.0014), and lower trait mindfulness (CAMS-R, P= 0.02). No difference between groups for PSS or FFMQ. Changes postMM: decreased CPP for all-voiced sentences for VH (P= 0.003), decreased mean SPL (P= 0.012) on sustained vowel for VH, increased mean phonatory airflow during sustained vowel for CVD (P = 0.012). VH demonstrated a decrease in CPP on the all-voice sentence, and CVD demonstrated an increase, resulting in a significant between group difference (P= 0.013). Participants reported improvements in voice, emotional and physical states. State anxiety decreased for both groups (= < 0.001). No other objective outcomes reached significance. CONCLUSIONS: After a brief MM, participants experienced improvement in physical, emotional, and cognitive states, and in their perceptions of their voice. Results indicate that a brief, single session of MM may be beneficial for some, but not sufficient to override habitual voice and speech patterns. Given the benefits of MM, future work should evaluate MM in a standard voice therapy protocol.

CD44 Contributes to the Regulation of MDR1 Protein and Doxorubicin Chemoresistance in Osteosarcoma.

Osteosarcoma is the most common type of pediatric bone tumor. Despite great advances in chemotherapy during the past decades, the survival rates of osteosarcoma patients remain unsatisfactory. Drug resistance is one of the main reasons, leading to treatment failure and poor prognosis. Previous reports correlated expression of cluster of differentiation 44 (CD44) with drug resistance and poor survival of osteosarcoma patients, however the underlying mechanisms are poorly defined. Here, we investigated the role of CD44 in the regulation of drug chemoresistance, using osteosarcoma cells isolated from mice carrying a mutation of the tumor suppressor neurofibromatosis type 2 (Nf2) gene. CD44 expression was knocked-down in the cells using CRISPR/Cas9 approach. Subsequently, CD44 isoforms and mutants were re-introduced to investigate CD44-dependent processes. Sensitivity to doxorubicin was analyzed in the osteosarcoma cells with modified CD44 expression by immunoblot, colony formation- and WST-1 assay. To dissect the molecular alterations induced by deletion of Cd44, RNA sequencing was performed on Cd44-positive and Cd44-negative primary osteosarcoma tissues isolated from Nf2-mutant mice. Subsequently, expression of candidate genes was evaluated by quantitative reverse transcription PCR (qRT-PCR). Our results indicate that CD44 increases the resistance of osteosarcoma cells to doxorubicin by up-regulating the levels of multidrug resistance (MDR) 1 protein expression, and suggest the role of proteolytically released CD44 intracellular domain, and hyaluronan interactions in this process. Moreover, high throughput sequencing analysis identified differential regulation of several apoptosis-related genes in Cd44-positive and -negative primary osteosarcomas, including p53 apoptosis effector related to PMP-22 (Perp). Deletion of Cd44 in osteosarcoma cells led to doxorubicin-dependent p53 activation and a profound increase in Perp mRNA expression. Overall, our results suggest that CD44 might be an important regulator of drug resistance and suggest that targeting CD44 can sensitize osteosarcoma to standard chemotherapy.

Investigating Past Trauma in Laryngoresponders Versus Non-Laryngoresponders: Piloting New Methods in an Exploratory Study.

OBJECTIVES/HYPOTHESIS: This exploratory pilot study aimed to probe the relationship between past experiences of trauma in people who self-identify as "laryngoresponders" compared to those who do not. It also explored the communicative context of past traumatic events in laryngoresponders versus non-laryngoresponders. STUDY DESIGN: Prospective, within-subjects experimental design. METHODS: 29 vocally healthy cisgender women (ages 19 to 56) completed a battery of validated self-report measures relating to their past traumatic experiences. Participants also completed two original self-report measures designed to provide insight about (1) where stress tends to manifest in their body and (2) communicative settings of participants' past trauma. RESULTS: Six participants (21%) self-identified a predictable laryngeal and/or vocal response to acute stress and thus comprise the laryngoresponders group. Laryngoresponders exhibited worse scores on 75% of all trauma-related variables compared to non-laryngoresponders, and Emotional Neglect was disproportionately represented in laryngoresponders. Participants with a reported history of childhood Emotional Neglect (83% of laryngoresponders, 35% of nonlaryngoresponders) reported quantitatively "less ideal" communication experiences in the context of past traumatic experiences. CONCLUSIONS: Other investigators identify the larynx as a "vulnerable body pathway" for some women. This pilot study of adult women without voice complaints revealed several commonalities amongst self-reported laryngoresponders, and compels further exploration of the voice-trauma relationship.

Acquired Resistance to Antiangiogenic Therapies in Hepatocellular Carcinoma Is Mediated by Yes-Associated Protein 1 Activation and Transient Expansion of Stem-Like Cancer Cells.

Induction of neoangiogenesis is a hallmark feature during disease progression of hepatocellular carcinoma (HCC). Antiangiogenetic compounds represent a mainstay of therapeutic approaches; however, development of chemoresistance is observed in the majority of patients. Recent findings suggest that tumor-initiating cells (TICs) may play a key role in acquisition of resistance, but the exact relevance for HCC in this process remains to be defined. Primary and established hepatoma cell lines were exposed to long-term sorafenib treatment to model acquisition of resistance. Treatment effects on TICs were estimated by sphere-forming capacity in vitro, tumorigenicity in vivo, and flow cytometry. Adaptive molecular changes were assessed by whole transcriptome analyses. Compensatory mechanisms of resistance were identified and directly evaluated. Sustained antiproliferative effect following sorafenib treatment was observed in three of six HCC cell lines and was followed by rapid regrowth, thereby mimicking responses observed in patients. Resistant cells showed induction in sphere forming in vitro and tumor-initiating capacity in vivo as well as increased number of side population and epithelial cell adhesion molecule-positive cells. Conversely, sensitive cell lines showed consistent reduction of TIC properties. Gene sets associated with resistance and poor prognosis, including Hippo/yes-associated protein (YAP), were identified. Western blot and immunohistochemistry confirmed increased levels of YAP. Combined treatment of sorafenib and specific YAP inhibitor consistently revealed synergistic antioncogenic effects in resistant cell lines. Conclusion: Resistance to antiangiogenic therapy might be driven by transient expansion of TICs and activation of compensatory pro-oncogenic signaling pathways, including YAP. Specific targeting of TICs might be an effective therapeutic strategy to overcome resistance in HCC.

Epigenetic modifications precede molecular alterations and drive human hepatocarcinogenesis.

Development of primary liver cancer is a multistage process. Detailed understanding of sequential epigenetic alterations is largely missing. Here, we performed Infinium Human Methylation 450k BeadChips and RNA-Seq analyses for genome-wide methylome and transcriptome profiling of cirrhotic liver (n = 7), low- (n = 4) and high-grade (n = 9) dysplastic lesions, and early (n = 5) and progressed (n = 3) hepatocellular carcinomas (HCC) synchronously detected in 8 patients with HCC with chronic hepatitis B infection. Integrative analyses of epigenetically driven molecular changes were identified and validated in 2 independent cohorts comprising 887 HCCs. Mitochondrial DNA sequencing was further employed for clonality analyses, indicating multiclonal origin in the majority of investigated HCCs. Alterations in DNA methylation progressively increased from liver cirrhosis (CL) to dysplastic lesions and reached a maximum in early HCCs. Associated early alterations identified by Ingenuity Pathway Analysis (IPA) involved apoptosis, immune regulation, and stemness pathways, while late changes centered on cell survival, proliferation, and invasion. We further validated 23 putative epidrivers with concomitant expression changes and associated with overall survival. Functionally, Striatin 4 (STRN4) was demonstrated to be epigenetically regulated, and inhibition of STRN4 significantly suppressed tumorigenicity of HCC cell lines. Overall, application of integrative genomic analyses defines epigenetic driver alterations and provides promising targets for potentially novel therapeutic approaches.

The Co-mutational Spectrum Determines the Therapeutic Response in Murine FGFR2 Fusion-Driven Cholangiocarcinoma.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer and a highly lethal malignancy. Chemotherapeutic options are limited, but a considerable subset of patients harbors genetic lesions for which targeted agents exist. Fibroblast growth factor receptor 2 (FGFR2) fusions belong to the most frequent and therapeutically relevant alterations in ICC, and the first FGFR inhibitor was recently approved for the treatment of patients with progressed, fusion-positive ICC. Response rates of up to 35% indicate that FGFR-targeted therapies are beneficial in many but not all patients. Thus far, no established biomarkers exist that predict resistance or response to FGFR-targeted therapies in patients with ICC. APPROACH AND RESULTS: In this study, we use an autochthonous murine model of ICC to demonstrate that FGFR2 fusions are potent drivers of malignant transformation. Furthermore, we provide preclinical evidence that the co-mutational spectrum acts not only as an accelerator of tumor development, but also modifies the response to targeted FGFR inhibitors. Using pharmacologic approaches and RNA-interference technology, we delineate that Kirsten rat sarcoma oncogene (KRAS)-activated mitogen-activated protein kinase signaling causes primary resistance to FGFR inhibitors in FGFR2 fusion-positive ICC. The translational relevance is supported by the observation that a subset of human FGFR2 fusion patients exhibits transcriptome profiles reminiscent of KRAS mutant ICC. Moreover, we demonstrate that combination therapy has the potential to overcome primary resistance and to sensitize tumors to FGFR inhibition. CONCLUSIONS: Our work highlights the importance of the co-mutational spectrum as a significant modifier of response in tumors that harbor potent oncogenic drivers. A better understanding of the genetic underpinnings of resistance will be pivotal to improve biomarker-guided patient selection and to design clinically relevant combination strategies.

In the Zoom Where It Happened: Telepractice and the Voice Clinic in 2020.

Telemedicine-conveying medical information virtually for planning, diagnosis, or treatment-has been a part of the American medical system for over 100 years. A constantly evolving modality, telepractice was a supplemental care delivery system for most speech-language pathologists (SLPs) until March 2020 when the COVID-19 pandemic forced clinical operations to halt in-person activities and convert as much as possible to virtual platforms. The purpose of this article is to provide an overview of the need for telepractice prior to and beyond the current pandemic, the efficacy of telepractice for the voice-specialized SLP, limitations of telepractice, and best practices for providing care over telepractice with a specific focus on voice disorder diagnosis and treatment.