Inhibition of SRC-3 as a potential therapeutic strategy for aggressive mantle cell lymphoma

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel of MCL cell lines. The in vivo efficacy of SI-10 was confirmed in two ibrutinib-resistant models: an immunocompetent disseminated A20 mouse model of B-cell lymphoma and a human PDX model of MCL. Notably, SI-10 treatment also resulted in a significant extension of survival in vivo with low toxicity in both ibrutinib-resistant murine models. We have investigated SI-10 as a novel anti-lymphoma compound via the inhibition of SRC-3 activity. These findings indicate that targeting SRC-3 should be investigated in combination with current clinical therapeutics as a novel strategy to expand the therapeutic index and to improve lymphoma outcomes.

Steroid receptor coactivators in Treg and Th17 cell biology and function

Steroid receptor coactivators (SRCs) are master regulators of transcription that play key roles in human physiology and pathology. SRCs are particularly important for the regulation of the immune system with major roles in lymphocyte fate determination and function, macrophage activity, regulation of nuclear factor κB (NF-κB) transcriptional activity and other immune system biology. The three members of the p160 SRC family comprise a network of immune-regulatory proteins that can function independently or act in synergy with each other, and compensate for - or moderate - the activity of other SRCs. Recent evidence indicates that the SRCs are key participants in governing numerous aspects of CD4+ T cell biology. Here we review findings that establish the SRCs as essential regulators of regulatory T cells (Tregs) and T helper 17 (Th17) cells, with a focus on their crucial roles in Treg immunity in cancer and Treg-Th17 cell phenotypic plasticity.

Steroid receptor coactivator-2 drives epithelial reprogramming that enables murine embryo implantation

Although we have shown that steroid receptor coactivator-2 (SRC-2), a member of the p160/SRC family of transcriptional coregulators, is essential for decidualization of both human and murine endometrial stromal cells, SRC-2's role in the earlier stages of the implantation process have not been adequately addressed. Using a conditional SRC-2 knockout mouse (SRC-2d/d ) in timed natural pregnancy studies, we show that endometrial SRC-2 is required for embryo attachment and adherence to the luminal epithelium. Implantation failure is associated with the persistent expression of Mucin 1 and E-cadherin on the apical surface and basolateral adherens junctions of the SRC-2d/d luminal epithelium, respectively. These findings indicate that the SRC-2d/d luminal epithelium fails to exhibit a plasma membrane transformation (PMT) state known to be required for the development of uterine receptivity. Transcriptomics demonstrated that the expression of genes involved in steroid hormone control of uterine receptivity were significantly disrupted in the SRC-2d/d endometrium as well as genes that control epithelial tight junctional biology and the emergence of the epithelial mesenchymal transition state, with the latter sharing similar biological properties with PMT. Collectively, these findings uncover a new role for endometrial SRC-2 in the induction of the luminal epithelial PMT state, which is a prerequisite for the development of uterine receptivity and early pregnancy establishment.

Modulation of the proteostasis network promotes tumor resistance to oncogenic KRAS inhibitors

Despite substantial advances in targeting mutant KRAS, tumor resistance to KRAS inhibitors (KRASi) remains a major barrier to progress. Here, we report proteostasis reprogramming as a key convergence point of multiple KRASi-resistance mechanisms. Inactivation of oncogenic KRAS down-regulated both the heat shock response and the inositol-requiring enzyme 1α (IRE1α) branch of the unfolded protein response, causing severe proteostasis disturbances. However, IRE1α was selectively reactivated in an ER stress-independent manner in acquired KRASi-resistant tumors, restoring proteostasis. Oncogenic KRAS promoted IRE1α protein stability through extracellular signal-regulated kinase (ERK)-dependent phosphorylation of IRE1α, leading to IRE1α disassociation from 3-hydroxy-3-methylglutaryl reductase degradation (HRD1) E3-ligase. In KRASi-resistant tumors, both reactivated ERK and hyperactivated AKT restored IRE1α phosphorylation and stability. Suppression of IRE1α overcame resistance to KRASi. This study reveals a druggable mechanism that leads to proteostasis reprogramming and facilitates KRASi resistance.

TRAF4-mediated nonproteolytic ubiquitination of androgen receptor promotes castration-resistant prostate cancer

Castration-resistant prostate cancer (CRPC) poses a major clinical challenge with the androgen receptor (AR) remaining to be a critical oncogenic player. Several lines of evidence indicate that AR induces a distinct transcriptional program after androgen deprivation in CRPCs. However, the mechanism triggering AR binding to a distinct set of genomic loci in CRPC and how it promotes CRPC development remain unclear. We demonstrate here that atypical ubiquitination of AR mediated by an E3 ubiquitin ligase TRAF4 plays an important role in this process. TRAF4 is highly expressed in CRPCs and promotes CRPC development. It mediates K27-linked ubiquitination at the C-terminal tail of AR and increases its association with the pioneer factor FOXA1. Consequently, AR binds to a distinct set of genomic loci enriched with FOXA1- and HOXB13-binding motifs to drive different transcriptional programs including an olfactory transduction pathway. Through the surprising upregulation of olfactory receptor gene transcription, TRAF4 increases intracellular cAMP levels and boosts E2F transcription factor activity to promote cell proliferation under androgen deprivation conditions. Altogether, these findings reveal a posttranslational mechanism driving AR-regulated transcriptional reprogramming to provide survival advantages for prostate cancer cells under castration conditions.

In-Hospital Cost Comparison for Open Versus Endoscopic Endonasal Approach for Meningioma Resection

Objective

To determine the in-hospital cost implications of an endoscopic expanded endonasal approach (EEEA) for meningioma resection relative to the open transcranial approach.

Methods

All anterior skull base meningioma surgeries performed over a period from January 1st, 2015 to October 31th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using R software. All cost data were converted into August 2021-equivalent dollar amounts using the United States Bureau of Labor Statistics consumer price index.

Results

Thirty-five patients met study criteria, including 27 patients undergoing an open transcranial approach and 8 undergoing an EEEA. Average length of stay for patients undergoing an open approach was 9.3 days compared to 5.6 within the EEEA group ( P = .126). The average total in-hospital cost of patient undergoing an EEEA was $35417.1 compared to $46406.9 among patients undergoing an open transcranial approach ( P = .168). On univariate analysis, the cost of an open transcranial approach relative to the EEEA was $10989.8 ( P = .411).

Conclusions

The open transcranial approach remained the dominant surgical approach to anterior skull base meningiomas over our study time period. However, despite limited patient numbers the EEEA was associated with decreased total in-hospital costs.

Steroid receptor coactivators - their role in immunity

Steroid Receptor Coactivators (SRCs) are essential regulators of transcription with a wide range of impact on human physiology and pathology. In immunology, SRCs play multiple roles; they are involved in the regulation of nuclear factor-κB (NF-κB), macrophage (MΦ) activity, lymphoid cells proliferation, development and function, to name just a few. The three SRC family members, SRC-1, SRC-2 and SRC-3, can exert their immunological function either in an independent manner or act in synergy with each other. In certain biological contexts, one SRC family member can compensate for lack of activity of another member, while in other cases one SRC can exert a biological function that competes against the function of another family counterpart. In this review we illustrate the diverse biological functionality of the SRCs with regard to their role in immunity. In the light of recent development of SRC small molecule inhibitors and stimulators, we discuss their potential relevance as modulators of the immunological activity of the SRCs for therapeutic purposes.

A steroid receptor coactivator small molecule "stimulator" attenuates post-stroke ischemic brain injury

Introduction: Pathologic remodeling of the brain following ischemic stroke results in neuronal loss, increased inflammation, oxidative stress, astrogliosis, and a progressive decrease in brain function. We recently demonstrated that stimulation of steroid receptor coactivator 3 with the small-molecule stimulator MCB-613 improves cardiac function in a mouse model of myocardial ischemia. Since steroid receptor coactivators are ubiquitously expressed in the brain, we reasoned that an MCB-613 derivative (MCB-10-1), could protect the brain following ischemic injury. To test this, we administered MCB-10-1 to rats following middle cerebral artery occlusion and reperfusion. Methods: Neurologic impairment and tissue damage responses were evaluated on day 1 and day 4 following injury in rats treated with control or 10-1. Results: We show that 10-1 attenuates injury post-stroke. 10-1 decreases infarct size and mitigates neurologic impairment. When given within 30 min post middle cerebral artery occlusion and reperfusion, 10-1 induces lasting protection from tissue damage in the ischemic penumbra concomitant with: (1) promotion of reparative microglia; (2) an increase in astrocyte NRF2 and GLT-1 expression; (3) early microglia activation; and (4) attenuation of astrogliosis. Discussion: Steroid receptor coactivator stimulation with MCB-10-1 is a potential therapeutic strategy for reducing inflammation and oxidative damage that cause neurologic impairment following an acute ischemic stroke.

Abstract A017: Bidirectional signaling between mitochondria and the nucleus dictates epigenetic rewiring to drive tumorigenesis

Cancer cells have acquired the ability to sense and adapt to varying conditions of nutrient sources in the tumor microenvironment. Mitochondria lay at the core of cellular metabolism, whereas the nucleus integrates cellular and environmental signals to activate gene transcription that alter cell function and cell fate. However, it remains largely unexplored how mitochondrial metabolic enzymes and nuclear transcriptional machineries communicate to drive gene regulation in response to metabolic stress. Biochemical screening identified a TCA cycle enzyme aconitase (ACO2), which functions as a critical mitochondrial regulator of de novo lipogenesis to sustain prostate tumor growth. Metabolic isotope tracing experiments revealed that the ACO2 enzyme promotes citrate biosynthesis required for de novo lipogenesis by reductive carboxylation of alpha-ketoglutarate generated from glutamine. Proteomics studies identified an acetylation mark lysine258 on ACO2 that induces increased enzymatic activity, whereas acetylation deficient Lys258Arg-ACO2 mutant was inactive, and failed to promote lipogenesis and tumor growth. To uncover nuclear signals that may stimulate ACO2 activity, we identified transcriptional suppression of a mitochondrial deacetylase SIRT3 by AR and its coregulator SRC-2, thereby preserving enhanced K258Ac mark on ACO2 facilitating increased lipogenesis. Interestingly our spontaneous bone metastatic mouse studies revealed that increased ACO2 activity regulated by the SIRT3/SRC-2 axis functions as a predominant survival factor for prostate tumors in the early stages of homing and colonization during bone metastasis, suggesting this pathway may be essential for metabolic adaptation in hostile microenvironment. Next, to investigate the biochemical control of gene transcription that may support tumor cell adaptation in the hostile microenvironment, we found a potential metabolic pathway that may support acetyl-CoA synthesis in the nucleus. Reversible enzymes IDH2 and ACO2 which can generate citrate from alpha-ketoglutarate to produce acetyl CoA were found to be localized in the nucleus. Interestingly, ablation of ACO2 and/or IDH2 was sufficient to significantly reduce several histone acetylation marks such as H3K9ac and H3K14ac. In isolated intact nucleus, these marks could be increased by addition of alpha-ketoglutarate thereby increasing the overall chromatin accessibility, however loss of ACO2 or IDH2 abrogated the effect, implying these enzymes are required to generate acetyl CoA in the nucleus independent of mitochondrial contribution. ATAC-seq analysis further revealed genetic inhibition of ACO2 significantly reduced chromatin accessibility with an approximate loss of 16626 peaks and gain of only 486 peaks compared to control (WT) cells. Our findings indicate a potential metabolic control in the nucleus that may regulate chromatin accessibility required for gene activation to favor tumor cell adaptation in a hostile microenvironment. This work is supported by the funds from NIH (R01CA252092 and DP2CA260421) to S.D.

Citation Format: Abhisha Sawant Dessai, Nadya Elhalawany, Eriko Katsuta, Christian Prechtl, Spencer Rosario, Bert W. O’Malley, Xiang H. Zhang, Subhamoy Dasgupta. Bidirectional signaling between mitochondria and the nucleus dictates epigenetic rewiring to drive tumorigenesis. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr A017.

Decidualization of human endometrial stromal cells requires steroid receptor coactivator-3

Steroid receptor coactivator-3 (SRC-3; also known as NCOA3 or AIB1) is a member of the multifunctional p160/SRC family of coactivators, which also includes SRC-1 and SRC-2. Clinical and cell-based studies as well as investigations on mice have demonstrated pivotal roles for each SRC in numerous physiological and pathophysiological contexts, underscoring their functional pleiotropy. We previously demonstrated the critical involvement of SRC-2 in murine embryo implantation as well as in human endometrial stromal cell (HESC) decidualization, a cellular transformation process required for trophoblast invasion and ultimately placentation. We show here that, like SRC-2, SRC-3 is expressed in the epithelial and stromal cellular compartments of the human endometrium during the proliferative and secretory phase of the menstrual cycle as well as in cultured HESCs. We also found that SRC-3 depletion in cultured HESCs results in a significant attenuation in the induction of a wide-range of established biomarkers of decidualization, despite exposure of these cells to a deciduogenic stimulus and normal progesterone receptor expression. These molecular findings are supported at the cellular level by the inability of HESCs to morphologically transform from a stromal fibroblastoid cell to an epithelioid decidual cell when endogenous SRC-3 levels are markedly reduced. To identify genes, signaling pathways and networks that are controlled by SRC-3 and potentially important for hormone-dependent decidualization, we performed RNA-sequencing on HESCs in which SRC-3 levels were significantly reduced at the time of administering the deciduogenic stimulus. Comparing HESC controls with HESCs deficient in SRC-3, gene enrichment analysis of the differentially expressed gene set revealed an overrepresentation of genes involved in chromatin remodeling, cell proliferation/motility, and programmed cell death. These predictive bioanalytic results were confirmed by the demonstration that SRC-3 is required for the expansion, migratory and invasive activities of the HESC population, cellular properties that are required in vivo in the formation or functioning of the decidua. Collectively, our results support SRC-3 as an important coregulator in HESC decidualization. Since perturbation of normal homeostatic levels of SRC-3 is linked with common gynecological disorders diagnosed in reproductive age women, this endometrial coregulator-along with its new molecular targets described here-may open novel clinical avenues in the diagnosis and/or treatment of a non-receptive endometrium, particularly in patients presenting non-aneuploid early pregnancy loss.

Oleuropein suppresses endometriosis progression and improves the fertility of mice with endometriosis

BACKGROUND

Endometriosis is an estrogen-dependent inflammatory reproductive disease. Therefore, systematic estrogen depletion and anti-inflammatory drugs are the current treatment for endometriosis. However, current endometriosis treatments have low efficacy and cause adverse effects in endometriosis patients. Consequently, alternative endometriosis treatments targeting endometriosis-specific factors are in demand. In this context, ERβ was selected as a druggable target for endometriosis due to its critical role in progression. Therefore, selective targeting of ERβ without inhibiting ERα activity would be a new paradigm for endometriosis treatment to overcome the low efficacy and adverse effects of hormonal endometriosis therapy.

METHODS

Cell-based ERβ and ERα activity assay systems were employed to define a selective ERβ-inhibiting chemical product from a library of natural products. A surgically induced endometriosis mouse model was used to determine whether an ERβ inhibitory drug suppressed endometriosis progression. Mice with endometriosis were randomly separated and then orally treated with vehicle or 25 mg/kg oleuropein (once a day for 21 days), an ERβ inhibitory drug. The volume of endometriotic lesions or luciferase activity of endometriotic lesions was examined to define the growth of ectopic lesions in mice with endometriosis. The metabolite and levels of metabolic enzymes of the liver and kidney were determined in the serum of female mice treated with vehicle and oleuropein (25 mg/kg, once a day for 21 days) to define the toxicity of oleuropein. The in vitro decidualization assay was conducted with normal human endometrial stromal cells and endometriotic stromal cells to determine whether oleuropein overcomes decidualization in endometriosis patients. The pregnancy rate and pup numbers of C57BL/6 J female mice with endometriosis treated with vehicle or oleuropein (n = 10/group) were determined after mating with male mice. The cytokine profile in endometriotic lesions treated with vehicle and oleuropein (25 mg/kg) was determined with a Mouse Cytokine Array Kit.

RESULTS

Among natural products, oleuropein selectively inhibited ERβ but not ERα activity in vitro. Oleuropein treatment inhibited the nuclear localization of ERβ in human endometrial cells upon estradiol treatment. Oleuropein (25 mg/kg) treatment suppressed the growth of mouse (6.6-fold) and human (sixfold) ectopic lesions in mice with endometriosis compared to the vehicle by inhibiting proliferation and activating apoptosis in endometriotic lesions. Oleuropein treatment did not cause reproductive toxicity in female mice. Additionally, mice with endometriosis subjected to oleuropein treatment had a higher pregnancy rate (100%) than vehicle-treated mice (70%). Furthermore, oleuropein treatment partially recovered the decidualization impact of human endometriotic stromal cells from endometriotic lesions compared to the vehicle. Oleuropein-treated mice with endometriosis exhibited significantly lower levels of cytokines directly regulated by ERβ in ectopic lesions than vehicle-treated mice, illustrating the improvement in the hyperinflammatory state of mice with endometriosis.

CONCLUSIONS

Oleuropein is a promising and novel nutraceutical product for nonhormonal therapy of endometriosis because it selectively inhibits ERβ, but not ERα, to suppress endometriosis progression and improve the fertility of mice with endometriosis.

Subclinical diagnosis of cisplatin-induced ototoxicity with biomarkers

A mouse model with cisplatin-induced ototoxicity was used in addition to human samples from the ITMAT Biobank at the University of Pennsylvania. Mouse auditory brainstem responses (ABR), inner ear histology, perilymph cisplatin sampling, and measurement of serum prestin via ELISA were performed. Human serum prestin level was measured via ELISA in patients with otological issues after cisplatin treatment and compared to matched controls. Serum prestin was significantly elevated before ABR threshold shifts in mice exposed to cisplatin compared to control mice. Prestin concentration also correlated with the severity of hearing threshold shifts in mice. After an extended rest post-cisplatin treatment, prestin returned to baseline levels in mice and humans. Prestin was significantly elevated in the serum before the onset of objective hearing loss and correlated with the severity of hearing damage indicating that prestin may function as an effective biomarker of cisplatin-induced ototoxicity. Human serum prestin levels responded similarly to mice > 3 weeks from ototoxic exposure with decreased levels of prestin in the serum.

In-Hospital Costs Associated With an Expanded Endonasal Approach to Anterior Skull Base Tumors

Objective:

To determine in-hospital costs associated with performing an EEA to anterior skull base pathology and to identify drivers of cost variability for patients undergoing endoscopic anterior skull base surgery.

Methods:

All endoscopic anterior skull base surgeries performed over a period from January 1st, 2015 to October 24th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using Stata software.

Results:

An EEA was associated with an average total in-hospital cost of $44 545. Compared to patients undergoing a transsphenoidal approach to pituitary tumor resection, EEA patients incurred higher in-hospital costs across all variables including a total cost increase of $15 921 (95% confidence interval $5720-26 122, P = .002). Univariate analysis of all endoscopic anterior skull base surgery patients showed a cost increase of $30 616 associated with post-operative cerebrospinal fluid (CSF) leak ($10 420-50 811, P = .004), $14 610 with post-operative diabetes insipidus (DI) ($4610-24 609, P = .004), and $11 522 with African-American patients relative to Caucasian patients ($3049-19 995, P = .008).

Conclusions:

Patients who undergo endoscopic EEA for resection of anterior skull base tumors typically incur greater in-hospital costs than patients undergoing a standard TSA. Post-operative complications such as CSF leak and DI, as well as ethnicity, are significant drivers of cost-variability.

Steroid receptor coactivator-3 inhibition generates breast cancer antitumor immune microenvironment

BACKGROUND

The tumor immune microenvironment (TIME) generated by cancer-infiltrating immune cells has a crucial role in promoting or suppressing breast cancer progression. However, whether the steroid receptor coactivator-3 (SRC-3) modulates TIME to progress breast cancer is unclear. Therefore, the present study evaluates whether SRC-3 generates a tumor-promoting TIME in breast tumors using a syngeneic immune-intact mouse model of breast cancer.

METHODS

We employed E0771 and 4T1 breast cancer in immune-intact syngeneic female C57BL/6 and BALB/c mice, respectively. SI-2, a specific small-molecule inhibitor of SRC-3, was administered daily (2.5 mg/kg) to E0771 and 4T1 breast tumor-bearing immune-intact mice. In addition, SRC-3 knockdown (KD)-E0771 and SRC-3 KD-4T1 cells and their parental breast cancer cells were injected into their syngeneic immune-intact female mice versus immune-deficiency mice to validate that the host immune system is required for breast tumor suppression by SRC-3 KD in immune-intact mice. Furthermore, tumor-infiltrating immune cells (such as CD4+, CD8+, CD56+, and Foxp3+ cells) in E0771 and 4T1 breast cancers treated with SI-2 and in SRC-3 KD E0771 and 4T1 breast cancers were determined by immunohistochemistry. Additionally, cytokine levels in SI-2-treated and SRC-3 KD E0771 breast tumors and their control cancers were defined with a Mouse Cytokine Array.

RESULTS

SRC-3 inhibition by SI-2 significantly suppressed the progression of breast cancer cells (E0771 and 4T1) into breast cancers in immune-intact syngeneic female mice. SRC-3 KD-E0771 and -4T1 breast cancer cells did not produce well-developed tumors in immune-intact syngeneic female mice compared to their parental cells, but SRC-3 KD breast cancers were well developed in immune-defective host mice. SRC-3 inhibition by SI-2 and SRC-3 KD effectively increased the numbers of cytotoxic immune cells, such as CD4+ and CD8+ T cells and CD56+ NK cells, and Interferon γ (Ifng) in breast cancers compared to vehicle. However, SI-2 treatment reduced the number of tumor-infiltrating CD4+/Foxp3+ regulatory T (Treg) cells compared to vehicle treatment. In addition, SRC-3 inhibition by SI-2 and SRC-3 KD increased C-X-C motif chemokine ligand 9 (Cxcl9) expression in breast cancer to recruit C-X-C motif chemokine receptor 3 (Cxcr3)-expressing cytotoxic immune cells into breast tumors.

CONCLUSIONS

SRC-3 is a critical immunomodulator in breast cancer, generating a protumor immune microenvironment. SRC-3 inhibition by SI-2 or SRC-3 KD activates the Cxcl9/Cxcr3 axis in breast tumors and enhances the antitumor immune microenvironment to suppress breast cancer progression.

A Steroid Receptor Coactivator Stimulator MCB-613 Attenuates Adverse Remodeling After Myocardial Infarction

Previous work from ours and other laboratories have shown that steroid receptor coactivators (SRCs) are involved in heart development and in mitigating cardiac dysfunction in cardiac injury models. Members of the p160 SRC family, SRC-1 (NCOA1), SRC-2 (NCOA2/TIF2/GRIP1) and SRC-3 (NCOA3/AIB1/ACTR/pCIP), interact with nuclear receptors and other transcription factors to drive target gene expression by assembling transcriptional coactivator complexes to increase transcription. This indicates a potential for SRC targeting drugs pertinent to cell migration, proliferation and survival-promoting paracrine interactions in cardiac tissue injury responses. We have identified a small molecule activator of SRCs (MCB-613) that selectively and reversibly binds to SRCs as shown by surface plasmon resonance and is a potent SRC stimulator that acts to greatly enhance SRC transcriptional activity with no apparent toxicity in mice. We postulated that MCB-613 could enable wound repair and preservation of cardiac function after an acute MI by reducing the extent of injury-related fibrosis and the subsequent chronic loss of cardiac function associated with non-contracting scar tissue. We thus tested the effect of MCB-613 on the cardiac injury response by administering MCB-613 two hours after ischemic injury in a mouse model of MI. Along with measurements of functional cardiac output and damage, we sought to identify the cell-type specific responses responsible for MCB-613’s cardio-protective effects by utilizing single cell transcriptomics of cardiac interstitial cells to characterize the effects of SRC stimulation on cardiac function post-MI. We show that MCB-613, a potent small molecule stimulator of steroid receptor coactivators (SRCs) attenuates pathological remodeling post-MI. MCB-613 decreases infarct size, apoptosis, hypertrophy, and fibrosis while maintaining significant cardiac function. MCB-613, when given within hours post-MI, induces lasting protection from adverse remodeling concomitant with: (i) inhibition of macrophage inflammatory signaling and IL-1 signaling which attenuates the acute inflammatory response, (ii) attenuation of fibroblast differentiation, and (iii) promotion of Tsc22d3 expressing macrophages - all of which may limit inflammatory damage. Our results indicate MCB-613 controls the cellular interstitial cardiac repair response to ischemia. Distinct molecular and cellular mechanisms related to stimulation of SRC-3 have been identified that pave the way for the further exploration of SRCs as drug targets that can be engaged to improve the management of myocardial injury response outcomes. SRC stimulation with MCB-613 (and derivatives) is a potential novel therapeutic approach for inhibiting cardiac dysfunction after MI.

A genome-scale CRISPR Cas9 dropout screen identifies synthetically lethal targets in SRC-3 inhibited cancer cells

Steroid receptor coactivator 3 (SRC-3/NCoA3/AIB1), is a key regulator of gene transcription and it plays a central role in breast cancer (BC) tumorigenesis, making it a potential therapeutic target. Beyond its function as an important regulator of estrogen receptor transcriptional activity, SRC-3 also functions as a coactivator for a wide range of other transcription factors, suggesting SRC-3 inhibition can be beneficial in hormone-independent cancers as well. The recent discovery of a potent SRC-3 small molecule inhibitor, SI-2, enabled the further development of additional related compounds. SI-12 is an improved version of SI-2 that like SI-2 has anti-proliferative activity in various cancer types, including BC. Here, we sought to identify gene targets, that when inhibited in the presence of SI-12, would lead to enhanced BC cell cytotoxicity. We performed a genome-scale CRISPR-Cas9 screen in MCF-7 BC cells under conditions of pharmacological pressure with SI-12. A parallel screen was performed with an ER inhibitor, fulvestrant, to shed light on both common and distinct activities between SRC-3 and ERα inhibition. Bearing in mind the key role of SRC-3 in tumorigenesis of other types of cancer, we extended our study by validating potential hits identified from the MCF-7 screen in other cancer cell lines.

Wound Healing-related Functions of the p160 Steroid Receptor Coactivator Family

Multicellular organisms have evolved sophisticated mechanisms to recover and maintain original tissue functions following injury. Injury responses require a robust transcriptomic response associated with cellular reprogramming involving complex gene expression programs critical for effective tissue repair following injury. Steroid receptor coactivators (SRCs) are master transcriptional regulators of cell-cell signaling that is integral for embryogenesis, reproduction, normal physiological function, and tissue repair following injury. Effective therapeutic approaches for facilitating improved tissue regeneration and repair will likely involve temporal and combinatorial manipulation of cell-intrinsic and cell-extrinsic factors. Pleiotropic actions of SRCs that are critical for wound healing range from immune regulation and angiogenesis to maintenance of metabolic regulation in diverse organ systems. Recent evidence derived from studies of model organisms during different developmental stages indicates the importance of the interplay of immune cells and stromal cells to wound healing. With SRCs being the master regulators of cell-cell signaling integral to physiologic changes necessary for wound repair, it is becoming clear that therapeutic targeting of SRCs provides a unique opportunity for drug development in wound healing. This review will provide an overview of wound healing-related functions of SRCs with a special focus on cellular and molecular interactions important for limiting tissue damage after injury. Finally, we review recent findings showing stimulation of SRCs following cardiac injury with the SRC small molecule stimulator MCB-613 can promote cardiac protection and inhibit pathologic remodeling after myocardial infarction.

Drug Combination in Cancer Treatment-From Cocktails to Conjugated Combinations

It is well recognized today that anticancer drugs often are most effective when used in combination. However, the establishment of chemotherapy as key modality in clinical oncology began with sporadic discoveries of chemicals that showed antiproliferative properties and which as a first attempt were used as single agents. In this review we describe the development of chemotherapy from its origins as a single drug treatment with cytotoxic agents to polydrug therapy that includes targeted drugs. We discuss the limitations of the first chemotherapeutic drugs as a motivation for the establishment of combined drug treatment as standard practice in spite of concerns about frequent severe, dose limiting toxicities. Next, we introduce the development of targeted treatment as a concept for advancement within the broader field of small-molecule drug combination therapy in cancer and its accelerating progress that was boosted by recent scientific and technological progresses. Finally, we describe an alternative strategy of drug combinations using drug-conjugates for selective delivery of cytotoxic drugs to tumor cells that potentiates future improvement of drug combinations in cancer treatment. Overall, in this review we outline the development of chemotherapy from a pharmacological perspective, from its early stages to modern concepts of using targeted therapies for combinational treatment.

Emerging roles of steroid receptor coactivators in stromal cell responses

Tissue parenchyma is the functional unit of an organ and all of the remaining cells within that organ collectively make up the tissue stroma. The stroma includes fibroblasts, endothelial cells, immune cells, and nerves. Interactions between stromal and epithelial cells are essential for tissue development and healing after injury. These interactions are governed by growth factors, inflammatory cytokines and hormone signaling cascades. The steroid receptor coactivator (SRC) family of proteins includes three transcriptional coactivators that facilitate the assembly of multi-protein complexes to induce gene expression in response to activation of many cellular transcription factor signaling cascades. They are ubiquitously expressed and are especially critical for the developmental function of steroid hormone responsive tissues. The SRCs are overexpressed in multiple cancers including breast, ovarian, prostate and endometrial cancers. In this review, we focus on the role of the SRCs in regulating the functions of stromal cell components responsible for angiogenesis, inflammation and cell differentiation.

Revisiting the Recommendation for Contralateral Tonsillectomy in HPV-Associated Tonsillar Carcinoma

Objective

Despite epidemiologic evidence that second primaries occur infrequently in HPV (human papillomavirus)–associated oropharyngeal squamous cell carcinoma, recent recommendations advocate for elective contralateral palatine tonsillectomy. We aimed to study this discordance and define the necessary extent of up-front surgery in a large contemporary cohort with long-term follow-up treated with unilateral transoral robotic surgery. We hypothesized that second primaries are discovered exceedingly rarely during follow-up and that survival outcomes are not compromised with a unilateral surgical approach.

Study Design

Retrospective cohort analysis.

Setting

Tertiary care academic center between 2007 and 2017.

Methods

Records for patients with p16-positive oropharyngeal squamous cell carcinoma of the tonsil and workup suggestive of unilateral disease who underwent ipsilateral transoral robotic surgery were analyzed for timing and distribution of locoregional recurrence, distant metastases, and second primary occurrence as well as survival characteristics.

Results

Among 295 included patients, 21 (7.1%) had a locoregional recurrence; 17 (5.8%) had a distant recurrence; and 3 (1.0%) had a second primary during a median follow-up of 48.0 months (interquartile range, 29.5-62.0). Only 1 (0.3%) had a second primary found in the contralateral tonsil. The 2- and 5-year estimates of overall survival were 95.5% (SE, 1.2%) and 90.1% (SE, 2.2%), respectively, while the 2- and 5-year estimates of disease-free survival were 90.0% (SE, 1.8%) and 84.7% (SE, 2.3%).

Conclusion

Second primary occurrence in the contralateral tonsil was infrequent, and survival outcomes were encouraging with unilateral surgery. This provides a rationale for not routinely performing elective contralateral tonsillectomy in patients whose workup suggests unilateral disease.

Steroid receptor coactivator-3 as a target for anaplastic thyroid cancer

Anaplastic thyroid carcinoma (ATC) is an aggressive malignancy without effective therapeutic options to improve survival. Steroid receptor coactivator-3 (SRC-3) is a transcriptional coactivator whose amplification and/or overexpression has been identified in many cancers. In this study, we explored the expression of SRC-3 in ATCs and the effects of a new class of SRC-3 inhibitor-2 (SI-2) in human ATC cells (THJ-11T and THJ-16T cells) and mouse xenograft models to assess therapeutic potential of SI-2 for the treatment of ATC. SRC-3 protein abundance was significantly higher in human ATC tissue samples and ATC cells than in differentiated thyroid carcinomas or normal controls. SI-2 treatment effectively reduced the SRC-3 expression in both ATC cells and ATC xenograft tumors induced by these cells. Cancer cell survival in ATC cells and tumor growth in xenograft tumors were significantly reduced by SI-2 treatment through induction of cancer cell apoptosis and cell cycle arrest. SI-2 also reduced cancer stem-like cells as shown by an inhibition of tumorsphere formation, ALDH activity, and expression of stem cell markers in ATC. These findings indicate that SRC-3 is a potential therapeutic target for treatment of ATC patients and that SI-2 is a potent and promising candidate for a new therapeutic agent.

12-h clock regulation of genetic information flow by XBP1s

Our group recently characterized a cell-autonomous mammalian 12-h clock independent from the circadian clock, but its function and mechanism of regulation remain poorly understood. Here, we show that in mouse liver, transcriptional regulation significantly contributes to the establishment of 12-h rhythms of mRNA expression in a manner dependent on Spliced Form of X-box Binding Protein 1 (XBP1s). Mechanistically, the motif stringency of XBP1s promoter binding sites dictates XBP1s’s ability to drive 12-h rhythms of nascent mRNA transcription at dawn and dusk, which are enriched for basal transcription regulation, mRNA processing and export, ribosome biogenesis, translation initiation, and protein processing/sorting in the Endoplasmic Reticulum (ER)-Golgi in a temporal order consistent with the progressive molecular processing sequence described by the central dogma information flow (CEDIF). We further identified GA-binding proteins (GABPs) as putative novel transcriptional regulators driving 12-h rhythms of gene expression with more diverse phases. These 12-h rhythms of gene expression are cell autonomous and evolutionarily conserved in marine animals possessing a circatidal clock. Our results demonstrate an evolutionarily conserved, intricate network of transcriptional control of the mammalian 12-h clock that mediates diverse biological pathways. We speculate that the 12-h clock is coopted to accommodate elevated gene expression and processing in mammals at the two rush hours, with the particular genes processed at each rush hour regulated by the circadian and/or tissue-specific pathways.

Distinct from the well-known 24-hour circadian clock, this study shows that the mammalian 12-hour clock upregulates genetic information flow capacity during the two "rush hours" (dawn and dusk) in a manner dependent on the transcription factor XBP1s.

Genomic Function of Estrogen Receptor β in Endometriosis

Estrogen receptor (ER) β plays a critical role in endometriosis progression because cytoplasmic ERβ stimulates proinflammatory signaling in ectopic lesions and prevents apoptosis to promote their survival. However, the role of "nuclear ERβ" in endometriosis progression is not known. This critical knowledge gap obscures our understanding of the full molecular etiology of ERβ-mediated endometriosis progression. To fill this void, we generated an ERβ-regulated transcriptome and ERβ cistrome in ectopic lesions and the eutopic endometrium of mice with endometriosis by using a new endometrium-specific FLAG-tagged human ERβ overexpression mouse model. The integration of these omics data sets revealed that ERβ stimulated the proliferation activities of ectopic lesions and the eutopic endometrium by directly upregulating MYC and E2 transcription factor target genes and genes associated with the G2/M transition. Additionally, ERβ stimulated gene expression associated with TNFα/nuclear factor κB (NF-κB) signaling, epithelial-mesenchymal transition, reactive oxygen species signaling, IL-6/Janus kinase (JAK)/signal transducer and activator of transcription (STAT)3 signaling, and hypoxia signaling and suppressed IFNα signaling in ectopic lesions to enhance endometriosis progression. ERβ also stimulated gene expression associated with the unfolded protein response and IL-6/JAK/STAT3 inhibitory signaling and suppressed TNFα/NF-κB signaling in the eutopic endometrium to cause endometriosis-associated endometrial dysfunction. Therefore, nuclear ERβ-regulated gene networks provide critical clues to understand the molecular etiology and complexity of endometriosis and endometriosis-associated endometrial dysfunction.

Mitochondrial pyruvate import is a metabolic vulnerability in androgen receptor-driven prostate cancer

Specific metabolic underpinnings of androgen receptor (AR)-driven growth in prostate adenocarcinoma (PCa) are largely undefined, hindering the development of strategies to leverage the metabolic dependencies of this disease when hormonal manipulations fail. Here we show that the mitochondrial pyruvate carrier (MPC), a critical metabolic conduit linking cytosolic and mitochondrial metabolism, is transcriptionally regulated by AR. Experimental MPC inhibition restricts proliferation and metabolic outputs of the citric acid cycle (TCA) including lipogenesis and oxidative phosphorylation in AR-driven PCa models. Mechanistically, metabolic disruption resulting from MPC inhibition activates the eIF2α/ATF4 integrated stress response (ISR). ISR signaling prevents cell cycle progression while coordinating salvage efforts, chiefly enhanced glutamine assimilation into the TCA, to regain metabolic homeostasis. We confirm that MPC function is operant in PCa tumors in-vivo using isotopomeric metabolic flux analysis. In turn, we apply a clinically viable small molecule targeting the MPC, MSDC0160, to pre-clinical PCa models and find that MPC inhibition suppresses tumor growth in hormone-responsive and castrate-resistant conditions. Collectively, our findings characterize the MPC as a tractable therapeutic target in AR-driven prostate tumors.

Retinoid signaling controlled by SRC-2 in decidualization revealed by transcriptomics

Establishment of a successful pregnancy requires not only implantation of a healthy embryo into a receptive uterus but also progesterone receptor (PGR)-dependent transformation of endometrial stromal cells (ESCs) into specialized decidual cells. Decidual cells support the developing embryo and are critical for placentation. We have previously shown that a known transcriptional coregulator of the PGR, steroid receptor coactivator-2 (SRC-2), is a critical driver of endometrial decidualization in both human and mouse endometrium. However, the full spectrum of genes transcriptionally controlled by SRC-2 in decidualizing ESCs has not been identified. Therefore, using an RNA- and chromatin immunoprecipitation-sequencing approach, we have identified the transcriptome of decidualizing human ESCs (hESCs) that requires SRC-2. We revealed that the majority of hESC genes regulated by SRC-2 are associated with decidualization. Over 50% of SRC-2-regulated genes are also controlled by the PGR. While ontology analysis showed that SRC-2-dependent genes are functionally linked to signaling processes known to underpin hESC decidualization, cell membrane processes were significantly enriched in this analysis. Follow-up studies showed that retinoid signaling is dependent on SRC-2 during hESC decidualization. Specifically, SRC-2 is required for full induction of the retinol transporter, stimulated by retinoic acid 6 (STRA6), which is essential for hESC decidualization. Together our findings show that a critical subset of genes transcriptionally reprogramed by PGR during hESC decidualization requires SRC-2. Among the multiple genes, pathways and networks that are dependent on SRC-2 during hESC decidualization, first-line analysis supports a critical role for this coregulator in maintaining retinoid signaling during progesterone-driven decidualization.

A novel mathematical method for disclosing oscillations in gene transcription: A comparative study

Circadian rhythmicity, the 24-hour cycle responsive to light and dark, is determined by periodic oscillations in gene transcription. This phenomenon has broad ramifications in physiologic function. Recent work has disclosed more cycles in gene transcription, and to the uncovering of these we apply a novel signal processing methodology known as the pencil method and compare it to conventional parametric, nonparametric, and statistical methods. Methods: In order to assess periodicity of gene expression over time, we analyzed a database derived from livers of mice entrained to a 12-hour light/12-hour dark cycle. We also analyzed artificially generated signals to identify differences between the pencil decomposition and other alternative methods. Results: The pencil decomposition revealed hitherto-unsuspected oscillations in gene transcription with 12-hour periodicity. The pencil method was robust in detecting the 24-hour circadian cycle that was known to exist, as well as confirming the existence of shorter-period oscillations. A key consequence of this approach is that orthogonality of the different oscillatory components can be demonstrated. thus indicating a biological independence of these oscillations, that has been subsequently confirmed empirically by knocking out the gene responsible for the 24-hour clock. Conclusion: System identification techniques can be applied to biological systems and can uncover important characteristics that may elude visual inspection of the data. Significance: The pencil method provides new insights on the essence of gene expression and discloses a wide variety of oscillations in addition to the well-studied circadian pattern. This insight opens the door to the study of novel mechanisms by which oscillatory gene expression signals exert their regulatory effect on cells to influence human diseases.

Unveiling "Musica Universalis" of the Cell: A Brief History of Biological 12-Hour Rhythms

"Musica universalis" is an ancient philosophical concept claiming the movements of celestial bodies follow mathematical equations and resonate to produce an inaudible harmony of music, and the harmonious sounds that humans make were an approximation of this larger harmony of the universe. Besides music, electromagnetic waves such as light and electric signals also are presented as harmonic resonances. Despite the seemingly universal theme of harmonic resonance in various disciplines, it was not until recently that the same harmonic resonance was discovered also to exist in biological systems. Contrary to traditional belief that a biological system is either at stead-state or cycles with a single frequency, it is now appreciated that most biological systems have no homeostatic "set point," but rather oscillate as composite rhythms consisting of superimposed oscillations. These oscillations often cycle at different harmonics of the circadian rhythm, and among these, the ~12-hour oscillation is most prevalent. In this review, we focus on these 12-hour oscillations, with special attention to their evolutionary origin, regulation, and functions in mammals, as well as their relationship to the circadian rhythm. We further discuss the potential roles of the 12-hour clock in regulating hepatic steatosis, aging, and the possibility of 12-hour clock-based chronotherapy. Finally, we posit that biological rhythms are also musica universalis: whereas the circadian rhythm is synchronized to the 24-hour light/dark cycle coinciding with the Earth's rotation, the mammalian 12-hour clock may have evolved from the circatidal clock, which is entrained by the 12-hour tidal cues orchestrated by the moon.

Risk of lymph node metastasis and recommendations for elective nodal treatment in squamous cell carcinoma of the nasal cavity and maxillary sinus: a SEER analysis

BACKGROUND

Risk of nodal involvement in patients with squamous cell carcinomas (SCC) of the nasal cavity and maxillary sinus has not been well defined, especially by risk factors beyond local T-stage. Additional criteria defining patients at highest risk, as well as specific nodal levels at highest risk, has been limited in small retrospective series. We describe a population-based assessment of specific nodal involvement in this group.

MATERIAL AND METHODS

The Surveillance, Epidemiology and End Results (SEER) database from 2004 to 2010 identified 1283 eligible patients with SCC of the nasal cavity or maxillary sinus. Neck involvement and individual nodal level involvement at presentation were assessed, and comparison made with a contemporaneous cohort of patients with a borderline clinically significant risk of nodal involvement and recurrence.

RESULTS

Among 1283 patients, 182 (14.2%) had nodal involvement at presentation (4-27% by site and local extension). T-stage alone was associated with higher rates of nodal involvement in maxillary sinus SCC, while higher T-stage and size >2 cm were associated with higher rates of nodal involvement in nasal cavity SCC on multivariable analysis. Facial nodes and cervical nodes at levels 1 and 2 have the highest rates of involvement in T4a nasal cavity SCC, whereas nodal levels 1, 2, and/or 3 have the highest rates of involvement in T2 or higher maxillary sinus SCC when compared with a clinical reference standard.

CONCLUSION

In this population-based study, there are high rates of initial nodal involvement when stratified by local extent determined by T-stage in nasal cavity SCC and maxillary sinus SCC, and independently by size in nasal cavity SCC. Involvement of the facial and nodal levels 1-3 varies depending on site and local extent of tumor involvement. These observations may help guide treatment decision making in the inclusion of and extent of elective nodal treatment fields.

Coactivator-Dependent Oscillation of Chromatin Accessibility Dictates Circadian Gene Amplitude via REV-ERB Loading

A central mechanism for controlling circadian gene amplitude remains elusive. We present evidence for a "facilitated repression (FR)" model that functions as an amplitude rheostat for circadian gene oscillation. We demonstrate that ROR and/or BMAL1 promote global chromatin decondensation during the activation phase of the circadian cycle to actively facilitate REV-ERB loading for repression of circadian gene expression. Mechanistically, we found that SRC-2 dictates global circadian chromatin remodeling through spatial and temporal recruitment of PBAF members of the SWI/SNF complex to facilitate loading of REV-ERB in the hepatic genome. Mathematical modeling highlights how the FR model sustains proper circadian rhythm despite fluctuations of REV-ERB levels. Our study not only reveals a mechanism for active communication between the positive and negative limbs of the circadian transcriptional loop but also establishes the concept that clock transcription factor binding dynamics is perhaps a central tenet for fine-tuning circadian rhythm.

Using PD-L1 to Induce Chemosensitization of Head and Neck Squamous Cell Carcinoma

Objectives:

(1) Investigate the impact of programmed cell death ligand 1 (PD-L1) on the response to Cisplatin (CDDP) therapy in head and neck squamous cell carcinoma (HNSCC). (2) Quantify the effect of CDDP treatment on the expression of PD-L1 in HNSCC cells. (3) Evaluate the impact of PD-L1 down-regulation on the chemosensitivty of HNSCC cells. (4) Describe the implications of PD-L1 modulation on the efficacy of current platinum-based chemotherapeutic agents in HNSCC.

Methods:

In vitro experiments were performed from November 2013 to January 2014 at the University of Pennsylvania Gene and Molecular Therapy Laboratory with 4 well-characterized human HNSCC cell lines. Quantitative polymerase chain reaction (qPCR) and western blot were conducted to determine the baseline and post-CDDP treatment PD-L1 gene expression. Knockdown of PD-L1 expression using siRNA was then performed to induce chemosensitization of HNSCC cells to CDDP. Cells treated with CDDP were compared with untreated controls to evaluate cytotoxicity.

Results:

Treatment of HNSCC cells with CDDP resulted in increased transcription and translation of PD-L1 compared with baseline levels. Subsequent knockdown of PD-L1 expression in HNSCC cells using siRNA resulted in increased CDDP cytotoxicity compared with control HNSCC cells.

Conclusions:

Increased PD-L1 expression in response to CDDP therapy and improved chemosensitization with its down-regulation are significant findings that highlight the role of PD-L1 in determining the efficacy of chemotherapeutic agents. Our findings demonstrate that disruption of the PD-L1 protein leads to increased sensitivity of HNSCC cells to CDDP, suggesting a potential combination therapeutic strategy for patients with CDDP-resistant HNSCC.

Effect of HPV on Posttreatment Weight in Head and Neck Squamous-Cell Carcinoma: A Pilot Study

Objectives:

Unlike head and neck squamous cell carcinoma (HNSCC) caused by tobacco and alcohol use, human papillomavirus (HPV)–related HNSCC has better survival outcomes. The aim of our study was to determine if post-treatment weight change was different between HPV positive and negative oral tongue and oropharyngeal squamous cell carcinoma (OPC) patients.

Methods:

We conducted a retrospective cohort study. Oral tongue and OPC patients with initial surgery or radiation/chemotherapy in 2010 were identified using the University of Pennsylvania Tumor Registry. Those with p16 testing as a surrogate marker for high-risk HPV were enrolled. Patient characteristics at diagnosis were collected, and the outcomes were mean weights at pretreatment and 0-6, 6-12, 12-18, and 18-24 month posttreatment visits.

Results:

We identified 50 survivors with p16 testing and follow-up weights. Seventy-four percent (n = 37) were p16-positive. Compared with p16-negative patients, p16-positive patients were significantly more likely to be younger (56 ± 11 vs 72 ± 12, P = .0001), at AJCC TNM stage 4 (72% vs 27%, P = .010), and have higher mean weights at pretreatment and all posttreatment visits ( P < .05). Mean weights at pretreatment and posttreatment 0-6, 6-12, 12-18, and 18-24 month follow-up visits were 164 ± 40, 160 ± 40, 159 ± 39, 160 ± 38, and 154 ± 35 pounds, respectively, in p16-negative patients, but were 194 ± 47, 171 ± 38, 172 ± 39, 174 ± 44, and 187 ± 53 pounds, respectively, in p16-positive patients, which improved from 0-6 to 18-24 month visits.

Conclusions:

Although the traditional post-treatment weight loss was still seen in p16-negative patients, p16-positive patients were able to gain weight during 24-month post-treatment follow-up after the initial rapid posttreatment weight loss.

Proteomics analysis of the non-muscle myosin heavy chain IIa-enriched actin-myosin complex reveals multiple functions within the podocyte

MYH9 encodes non-muscle myosin heavy chain IIA (NMMHCIIA), the predominant force-generating ATPase in non-muscle cells. Several lines of evidence implicate a role for MYH9 in podocytopathies. However, NMMHCIIA‘s function in podocytes remains unknown. To better understand this function, we performed immuno-precipitation followed by mass-spectrometry proteomics to identify proteins interacting with the NMMHCIIA-enriched actin-myosin complexes. Computational analyses revealed that these proteins belong to functional networks including regulators of cytoskeletal organization, metabolism and networks regulated by the HIV-1 gene nef. We further characterized the subcellular localization of NMMHCIIA within podocytes in vivo, and found it to be present within the podocyte major foot processes. Finally, we tested the effect of loss of MYH9 expression in podocytes in vitro, and found that it was necessary for cytoskeletal organization. Our results provide the first survey of NMMHCIIA-enriched actin-myosin-interacting proteins within the podocyte, demonstrating the important role of NMMHCIIA in organizing the elaborate cytoskeleton structure of podocytes. Our characterization of NMMHCIIA’s functions goes beyond the podocyte, providing important insights into its general molecular role.

Perturbing the cellular levels of steroid receptor coactivator-2 impairs murine endometrial function

As pleiotropic coregulators, members of the p160/steroid receptor coactivator (SRC) family control a broad spectrum of transcriptional responses that underpin a diverse array of physiological and pathophysiological processes. Because of their potent coregulator properties, strict controls on SRC expression levels are required to maintain normal tissue functionality. Accordingly, an unwarranted increase in the cellular levels of SRC members has been causally linked to the initiation and/or progression of a number of clinical disorders. Although knockout mouse models have underscored the critical non-redundant roles for each SRC member in vivo, there are surprisingly few mouse models that have been engineered to overexpress SRCs. This deficiency is significant since SRC involvement in many of these disorders is based on unscheduled increases in the levels (rather than the absence) of SRC expression. To address this deficiency, we used recent mouse technology that allows for the targeted expression of human SRC-2 in cells which express the progesterone receptor. Through cre-loxP recombination driven by the endogenous progesterone receptor promoter, a marked elevation in expression levels of human SRC-2 was achieved in endometrial cells that are positive for the progesterone receptor. As a result of this increase in coregulator expression, female mice are severely subfertile due to a dysfunctional uterus, which exhibits a hypersensitivity to estrogen exposure. Our findings strongly support the proposal from clinical observations that increased levels of SRC-2 are causal for a number of endometrial disorders which compromise fertility. Future studies will use this mouse model to decipher the molecular mechanisms that underpin the endometrial defect. We believe such mechanistic insight may provide new molecular descriptors for diagnosis, prognosis, and/or therapy in the clinical management of female infertility.

A Novel Regulated Nanohydrogel Delivery System for Inner Ear Application

Objectives:

1) Develop a novel chitosan-hydrogel-based nanoparticle delivery system (nanohydrogel) for inner ear application and to evaluate its structures and release kinetics in vitro. 2) Evaluate if the nanohydrogel delivery system can be turned off using an enzymatic regulator for inner ear delivery. 3) Evaluate the inner ear distribution of nanoparticles following round window membrane application in a mouse model.

Methods:

Nanoparticles labeled with fluorescence were constructed and loaded into a chitosan-based hydrogel to form a nanohydrogel delivery system. In vitro studies were performed to evaluate the thermosensitivity, structure, and nanoparticle release kinetics of the nanohydrogel with/without chitosanase enzymatic regulation. Morphologic studies were performed to evaluate the nanoparticle delivery and distribution within the inner ear structures in a mouse model.

Results:

After obtaining a homogeneous, viscous and thermosensitive nanohydrogel system, in vitro studies showed that the nanohydrogel can carry and release nanoparticles in a controlled and sustained manner, and chitosanase can effectively regulate this release if needed. A matrix-like ultrastructure containing nanosized particles was confirmed. In vivo findings further confirm that the nanohydrogel delivered nanoparticles into the perilymphatic system and reached cellular structures of the inner ear in our mouse model.

Conclusions:

Our study suggests that the nanohydrogel system has the potential to safely deliver drugs or biomaterials in a controlled and sustained manner for inner ear application. This system could be used for targeted therapy for inner ear diseases that require safe and non-invasive delivery approaches.

Management of the Unknown Primary in the Era of HPV and Robotics

Objectives:

A subset of patients with squamous cell carcinoma of the head and neck present with a cervical metastasis from an unknown primary site. Currently, many of these patients have human papillomavirus (HPV) positive tumors, making the oropharynx the most likely primary site. Objectives: 1) Develop a minimally invasive approach to identify and definitively treat patients initially diagnosed with carcinoma of unknown primary (CUP) using transoral robotic surgery (TORS). Additionally, we anticipate that this aggressive approach will yield the primary lesion in a higher subset of patients.

Methods:

A retrospective chart review study was conducted to evaluate a novel minimally-invasive management approach using TORS to assess the primary site.

Results:

We identified 12 patients with CUP of the head and neck that had undergone this approach from December 2011 to April 2012. Ten patients were classified as HPV positive using p16 staining as surrogate marker. The primary site was identified in 10 of 12 patients (83%), the majority of which was found to be the base of tongue.

Conclusions:

We have developed a minimally invasive surgical approach using TORS for the diagnosis and subsequent management of the patient with CUP. Using this algorithm, we are able to move from frozen section directly to an en bloc definitive resection in many patients. Our results show a significant rate of primary tumor identification using a robotic-assisted approach and support the rationale for further investigation of this technique.

Inhibition of Novel Cetuximab Resistance Pathway Leads to Improved Outcomes in Head and Neck Cancer

Objectives:

1) Determine if cetuximab resistance in head and neck squamous cell carcinoma (HNSCC) is regulated by increased nuclear translocation of Epidermal Growth Factor Receptor (EGFR) through an MRN-dependent Akt phosphorylation pathway. 2) Determine if targeted inhibition of the MRN complex, a key mediator of DNA damage response, can improve cetuximab sensitivity in HNSCC.

Methods:

Two well-characterized human HNSCC tumor cell lines, with differential resistance to cetuximab, were chosen for this study. Mirin, a novel molecular MRN inhibitor was used for this study. MTT and clonogenic assays were used to evaluate in vitro cytotoxicity. Western blot analysis was performed to evaluate protein expression. In vivo tumor growth was evaluated using molecular imaging.

Results:

As compared with sensitive cells, cetuximab resistant cells demonstrated increased MRN expression, increased Akt phosphorylation, and increased nuclear EGFR. The inhibition of MRN led to a dose-dependent decrease in Akt phosphorylation and nuclear EGFR translocation. Furthermore, MRN inhibition synergistically enhanced the cytotoxic effect of cetuximab in resistant cells ( P < 0.01).

Conclusions:

The findings from this study suggest a novel cetuximab resistance pathway involving MRN-mediated Akt phosphorylation, leading to increased nuclear translocation of EGFR. Furthermore, inhibition of MRN led to decreased Akt-phosphorylation, subsequently decreasing nuclear EGFR translocation, a key molecular mechanism involved in cetuximab resistance. Based on this discovery, inhibition of this pathway may serve as an effective therapeutic approach for HNSCC patients resistant to cetuximab.

Long-term Change of Body Mass Index after Head and Neck Cancer Treatment

Objectives:

Although head and neck cancer (HNC) is associated with weight loss, little is known about the long-term body mass index (BMI) change in HNC survivors. Our goal was to determine the long-term BMI change after HNC treatment.

Methods:

Retrospective cohort study on patients with oral cavity and pharyngeal squamous cell carcinoma who received initial treatment at the University of Pennsylvania Health System in 2009, and were then followed for 3 years. Patient demographics, height, tobacco and alcohol use, cancer type, AJCC stage, treatments, and weight at all visits were collected from medical records. Underweight was defined as BMI<18.5, normal was BMI 18.5-24.9, overweight was BMI 25.0-29.9, and obesity was BMI > 30. Logistic regression was performed to identify factors associated with long-term BMI changes.

Results:

We identified 211 patients with complete data and follow-up visits. At the time of diagnosis, 7% patients were underweight (n = 15), 34% had normal-weight (n = 72), 36% were overweight (n = 75) and 23% were obese (n = 49). At the last follow-up visit, 7% were underweight (n = 14), 42% were normal-weight (n = 82), 33% were overweight (n = 65) and 18% were obese (n = 36). Thus, 17% patients (n = 21) who were overweight or obese at diagnosis improved to normal weight at the end of 3-year follow-up, and this change was not significantly affected by patients’ age, gender, race, tobacco and alcohol use, cancer site, AJCC stage, and treatment type.

Conclusions:

Our study suggests BMI improves in overweight or obese HNC survivors after 3-year follow-up, and this change is independent of cancer severity and treatment type.

The Development of Nanoparticles for Targeted Head and Neck Cancer Detection with Molecular Imaging

Objectives:

1) Develop an accurate detection system for head and neck squamous cell carcinoma (HNSCC) using tumor specific nanoparticle-based probes. 2) Apply these probes for real-time non-invasive HNSCC detection using molecular imaging (MI) system.

Methods.

Fluorescence-labeled LDS nanoparticles targeting Hsp47 (a highly specific biomarker for HNSCC) were constructed. The HNSCC targeted properties of these constructs were evaluated in vitro using human HNSCC tumor cell lines and in a mouse model of HNSCC with a MI system.

Results:

Fluorescence-labeled LDS nanoparticles demonstrated HNSCC tumor cell targeting properties in vitro. Furthermore, this targeting strategy demonstrated accurate and real time tumor detection using MI system.

Conclusions:

Our study suggests that these novel nanoparticle-based HNSCC tumor-targeting constructs have the potential to be used clinically for non-invasive, accurate, and real time detection of tumors for patients evaluated for HNSCC.

Off-Label Uses of Drugs and Technology: What’s the Stigma?

Program Description:

The practice of otolaryngology is rapidly evolving with new technologies and pharmaceuticals introduced into use at an exponential rate. While most new interventions are Food and Drug Administration approved, some rely on their success in other fields of medicine and are applied into our field as experimental or are used in good faith with anecdotal benefits. The purpose of this multi-expert panel is to share the ethical considerations and controversies of such tools, with a special emphasis on the pathway for approval by the hospital as well as credentialing, off-label use of injectables and topical medications, and application of robotics in otolaryngology.

Educational Objectives:

1) Describe the process of introducing off-label medications, devices, and technologies into everyday practice. 2) List some commonly used topical and injectable medications and their off-label use in the various fields of otolaryngology. 3) Recognize the limitations that are inherent to the introduction of such innovations.

SRC-2 coactivator deficiency decreases functional reserve in response to pressure overload of mouse heart

A major component of the cardiac stress response is the simultaneous activation of several gene regulatory networks. Interestingly, the transcriptional regulator steroid receptor coactivator-2, SRC-2 is often decreased during cardiac failure in humans. We postulated that SRC-2 suppression plays a mechanistic role in the stress response and that SRC-2 activity is an important regulator of the adult heart gene expression profile. Genome-wide microarray analysis, confirmed with targeted gene expression analyses revealed that genetic ablation of SRC-2 activates the "fetal gene program" in adult mice as manifested by shifts in expression of a) metabolic and b) sarcomeric genes, as well as associated modulating transcription factors. While these gene expression changes were not accompanied by changes in left ventricular weight or cardiac function, imposition of transverse aortic constriction (TAC) predisposed SRC-2 knockout (KO) mice to stress-induced cardiac dysfunction. In addition, SRC-2 KO mice lacked the normal ventricular hypertrophic response as indicated through heart weight, left ventricular wall thickness, and blunted molecular signaling known to activate hypertrophy. Our results indicate that SRC-2 is involved in maintenance of the steady-state adult heart transcriptional profile, with its ablation inducing transcriptional changes that mimic a stressed heart. These results further suggest that SRC-2 deletion interferes with the timing and integration needed to respond efficiently to stress through disruption of metabolic and sarcomeric gene expression and hypertrophic signaling, the three key stress responsive pathways.

Regulated Chitosan-Based Inner-Ear Drug Delivery

Objective: 1) To evaluate a novel system for regulating the chitosan-glycero-phosphate (CGP)-based hydrogel drug delivery to the inner ear. 2) To understand the distribution of gentamicin in the inner ear following CGP drug delivery with and without regulation.

Method: Chitosanase, specifically targeting CGP, was identified and purified for its use as a CGP regulation system. In vitro and in vivo studies were conducted to evaluate the effect of the chitosanase on the inner ear drug delivery and distribution. Gentamicin-Texas Red (GTTR) was used for tracking the drug distribution.

Results: Purified chitosanase was confirmed with Western blot. The in vitro study showed that the chitosanase-based regulation system effectively controlled the gentamicin releasing. The in vivo data concur with in vitro findings and demonstrated that the gentamicin concentration in the inner ear can be successfully regulated by applying the chitosanase. Moreover, the gentamicin inner ear distribution can also be regulated by changing its inner ear concentration.

Conclusion: Our study suggests that the chitosanase-based regulation system can be effectively used for controlled inner ear drug delivery. This system has a potential to stop inner ear drug application when side effects or drug-related toxicities start to occur and should be used for safe drug application in the inner ear.

A Genetically Modified Viral Vector for Head and Neck Cancer

Objective: 1) To develop a novel genetically modified recombinant adenoviral vector that is expressing epidermal growth factor (EGF) and detargeting from natural coxsackie-adenoviral receptor (CAR). 2) To apply this novel vector to head and neck cancer (HNC) as an epidermal growth factor receptor (EGFR)-targeted approach.

Method: Wild-type adenoviral fiber knobs were genetically modified with EGF, and a novel adenoviral vector with EGF and EGFR binding properties was constructed. This novel construct was tested in the HNC tumor cells expressing a high level of EGFR.

Results: The novel genetically modified recombinant adenoviral vector demonstrated EGFR-targeted properties. The HNC tumor cells expressing high levels of EGFR showed much more viral targeted effects as compared to the cells with low or no EGFR. The nature CAR cell surface entering mechanism was not observed in the HNC tumor cells when the novel was vector applied.

Conclusion: Our study suggests that the novel genetically modified recombinant adenoviral vector has EGFR-targeted properties that target the HNC tumor cells, which commonly express high levels of EGFR. This vector has a potential for targeted delivering of diagnostic or therapeutic agents not only for HNC but for any tumor expressing EGFR.

Creation of Novel Nanocomplexes to Target Head and Neck Cancer

Objective: It is critically important to develop novel targeted strategies that can efficiently inhibit specific molecular pathways in tumor growth and development. The study investigates the potential of adenoviral/chitosan-PEG nanocomplexes with epidermal growth factor (EGF) for the targeting and treatment of EGF receptor (EGFR) overexpressing head and neck cancers (HNC).

Method: A construct with GFP-expressing adenoviral vector was coated with a Chitosan-PEG-EGF nanocomplex. The EGFR-expressing HNC tumor cells labeled with TdTomato were co-cultured with CHO tumor cells with coxsackievirus and adenovirus receptor (CAR), and without EGFR. Fluorescence microscopy was used to detect GFP expression after the treatment with targeted adenoviral/chitosan nanocomplex.

Results: As compared to wild-type adenovirus, the chitosan-PEG polymer coating cloaks the viral nanoparticle and prevents interaction with cells through the native CAR-mediated mechanisms. This significantly reduces nonspecific infection. Due to the TdTomato molecular marker being specifically expressed in the EGFR tumor cell line, the treated EGFR-expressing cells can be visualized by co-registration of GFP and TdTomato. The non-EGFR-expressing cells lack TdTomato and therefore only express the GFP. The adenoviral/chitosan-PEG nanocomplexes with EGF ligand demonstrated significantly increased EGFR tumor cell-specific GFP expression. The tumor cells without EGFR showed no GFP expression.

Conclusion: Our study suggests that the novel EGFR-targeted adenoviral/chitosan-PEG nanocomplex approach can effectively target HNC and has significant potential to deliver therapeutic agents specifically to the HNC tumor sites. It is also possible to track real-time tumor growth and spread through molecular imaging by incorporating fluorescent proteins into the payload.

Castleman’s Disease Masquerading as a Large Paraganglioma

Objective: 1) To describe a case of Castleman’s disease with unusual clinical and radiographic presentation as a somatostatin-positive mass in the poststyloid parapharyngeal space (PPS). 2) To review the literature, which does not report Castleman’s disease of the PPS, somatostatin-positive disease, or disease resulting in cranial neuropathy.

Method: The clinical presentation, imaging features, surgical findings, and pathology slides were reviewed in the case of an adult patient with a parapharyngeal space mass. The literature on Castleman’s disease was reviewed as was that on somatostatin-positive parapharyngeal space lesions. Permission was obtained from the patient to publish the findings.

Results: A 51-year-old male with 3 months of otalgia, hearing loss, and tinnitus underwent audiogram, revealing asymmetric hearing loss. Laryngoscopy showed a paretic true vocal cord. Magnetic resonance imaging (MRI) showed a 4.5-cm poststyloid PPS mass displacing the carotid artery anterolaterally. Octreoscan scan showed a significant uptake. Angiogram showed prominent vascular blush and feeders from the occipital artery. The patient underwent preoperative embolization of arterial feeders to the mass. A transcervical approach was used to access and remove the mass. Final histopathology is consistent with Castleman’s disease. Our review of the literature did not identify previously reported cases of octreotide-positive lymphoproliferative diseases.

Conclusion: This case demonstrates that poststyloid parapharyngeal masses in the medial portion of the parapharyngeal space may actually be lateral retropharyngeal nodes. Paragangliomas may also grow medially and present atypically and may be associated with vocal cord paralysis. This case is particularly unusual in that octreotide-positive Castleman’s has never been reported.