Tackling FGFR3-driven bladder cancer with a promising synergistic FGFR/HDAC targeted therapy.

Bladder cancer (BC) is one of the most prevalent malignancies worldwide and FGFR3 alterations are particularly common in BC. Despite approval of erdafitinib, durable responses for FGFR inhibitors are still uncommon and most patients relapse to metastatic disease. Given the necessity to discover more efficient therapies for BC, herein, we sought to explore promising synergistic combinations for BC with FGFR3 fusions.

Combinatorial Immunotherapy with Agonistic CD40 Activates Dendritic Cells to Express IL12 and Overcomes PD-1 Resistance.

Checkpoint inhibitors have revolutionized cancer treatment, but resistance remains a significant clinical challenge. Myeloid cells within the tumor microenvironment can modulate checkpoint resistance by either supporting or suppressing adaptive immune responses. Using an anti-PD-1-resistant mouse melanoma model, we show that targeting the myeloid compartment via CD40 activation and CSF1R blockade in combination with anti-PD-1 results in complete tumor regression in a majority of mice.

RASGRF1 Fusions Activate Oncogenic RAS Signaling and Confer Sensitivity to MEK Inhibition.

Purpose: The identification of actionable oncogenic alterations has enabled targeted therapeutic strategies for subsets of patients with advanced malignancies, including lung adenocarcinoma (LUAD). We sought to assess the frequency of known drivers and identify new candidate drivers in a cohort of LUAD from patients with minimal smoking history.

Experimental Design: We performed genomic characterization of 103 LUADs from patients with ≤10 pack-year smoking history.

Comprehensive Analysis of Metabolic Isozyme Targets in Cancer.

Unlabelled: Metabolic reprogramming is a hallmark of malignant transformation, and loss of isozyme diversity (LID) contributes to this process. Isozymes are distinct proteins that catalyze the same enzymatic reaction but can have different kinetic characteristics, subcellular localization, and tissue specificity. Cancer-dominant isozymes that catalyze rate-limiting reactions in critical metabolic processes represent potential therapeutic targets.

Bifunctional small molecules that mediate the degradation of extracellular proteins.

Targeted protein degradation (TPD) has emerged as a promising therapeutic strategy. Most TPD technologies use the ubiquitin-proteasome system, and are therefore limited to targeting intracellular proteins. To address this limitation, we developed a class of modular, bifunctional synthetic molecules called MoDE-As (molecular degraders of extracellular proteins through the asialoglycoprotein receptor (ASGPR)), which mediate the degradation of extracellular proteins.

Targeting Pyruvate Kinase M2 Phosphorylation Reverses Aggressive Cancer Phenotypes.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with low survival rate and a lack of biomarkers and targeted treatments. Here, we target pyruvate kinase M2 (PKM2), a key metabolic component of oncogenesis. In patients with TNBC, PKM2pS37 was identified as a prominent phosphoprotein corresponding to the aggressive breast cancer phenotype that showed a characteristic nuclear staining pattern and prognostic value.

Structure-Guided Identification of DNMT3B Inhibitors.

Methyltransferase 3 beta (DNMT3B) inhibitors that interfere with cancer growth are emerging possibilities for treatment of melanoma. Herein we identify small molecule inhibitors of DNMT3B starting from a homology model based on a DNMT3A crystal structure. Virtual screening by docking led to purchase of 15 compounds, among which 5 were found to inhibit the activity of DNMT3B with IC values of 13-72 μM in a fluorogenic assay.

Intratumoral delivery of RIG-I agonist SLR14 induces robust antitumor responses.

Cytosolic nucleic acid-sensing pathways can be triggered to enhance immune response to cancer. In this study, we tested the antitumor activity of a unique RIG-I agonist, stem loop RNA (SLR) 14. In the immunogenic tumor models, we observed significant tumor growth delay and an extended survival in SLR14-treated mice.

Neutralization of Pathogenic Fungi with Small-Molecule Immunotherapeutics.

Systemic fungal infections represent an important public health concern, and new antifungal agents are highly desirable. Herein, we describe the design, synthesis, and biological evaluation of a novel class of antifungal compounds called antibody-recruiting molecules targeting fungi (ARM-Fs). Our approach relies on the use of non-peptidic small molecules, which selectively bind fungal cells and recruit endogenous antibodies to their surfaces, resulting in immune-mediated clearance.

DNMT3b Modulates Melanoma Growth by Controlling Levels of mTORC2 Component RICTOR.

DNA methyltransferase DNMT3B is frequently overexpressed in tumor cells and plays important roles during the formation and progression of several cancer types. However, the specific signaling pathways controlled by DNMT3B in cancers, including melanoma, are poorly understood. Here, we report that DNMT3B plays a pro-tumorigenic role in human melanoma and that DNMT3B loss dramatically suppresses melanoma formation in the Braf/Pten mouse melanoma model.

Re-engineering the Immune Response to Metastatic Cancer: Antibody-Recruiting Small Molecules Targeting the Urokinase Receptor.

Developing selective strategies to treat metastatic cancers remains a significant challenge. Herein, we report the first antibody-recruiting small molecule (ARM) that is capable of recognizing the urokinase-type plasminogen activator receptor (uPAR), a uniquely overexpressed cancer cell-surface marker, and facilitating the immune-mediated destruction of cancer cells. A co-crystal structure of the ARM-U2/uPAR complex was obtained, representing the first crystal structure of uPAR complexed with a non-peptide ligand.

mTORC1 activation blocks BrafV600E-induced growth arrest but is insufficient for melanoma formation.

Braf(V600E) induces benign, growth-arrested melanocytic nevus development, but also drives melanoma formation. Cdkn2a loss in Braf(V600E) melanocytes in mice results in rare progression to melanoma, but only after stable growth arrest as nevi. Immediate progression to melanoma is prevented by upregulation of miR-99/100, which downregulates mTOR and IGF1R signaling.

The hematopoietic stem cell regulatory gene latexin has tumor-suppressive properties in malignant melanoma.

Despite recent advancements in therapy, melanoma remains a highly lethal skin cancer. A better understanding of the genetic and epigenetic changes responsible for melanoma formation and progression could result in the development of more effective treatments. Advanced melanomas are known to exhibit widespread promoter region CpG island methylation leading to the inactivation of key tumor suppressor genes.

Familial multiple pilomatrixomas as a presentation of attenuated adenomatosis polyposis coli.

Pilomatrixomas are benign follicular tumors that occur most commonly in children. Rare multiple or familial pilomatrixomas have been associated with myotonic dystrophy and other disorders. Although sporadic pilomatrixomas and hybrid cutaneous cysts with pilomatrixoma-like features have been observed in some kindreds with Gardner syndrome, an autosomal dominant form of familial adenomatous polyposis, no definitive association has been made with multiple or familial pilomatrixomas.

A transient epidermolysis bullosa simplex-like phenotype associated with bexarotene treatment in a G138E KRT5 heterozygote.

Basal keratinocyte lysis is the hallmark histopathological finding of epidermolysis bullosa simplex (EBS), a group of rare heritable mechanobullous disorders characterized by intraepidermal blister formation and skin fragility. Over 100 mutations, found predominantly in the genes encoding keratins 5 and 14 (KRT5, KRT14), have been described to account for a variety of clinical subtypes. EBS with mottled pigmentation (EBS-MP) is a rare variant featuring childhood-onset reticulate hyperpigmentation and focal palmoplantar keratoderma, typically associated with a P25L KRT5 mutation.

Redefining regulation of DNA methylation by RNA interference.

Epigenetic changes refer to heritable changes that may modulate gene expression without affecting DNA sequence. DNA methylation is one such heritable epigenetic change, which is causally associated with the transcription regulation of many genes in the mammalian genome. Altered DNA methylation has been implicated in a wide variety of human diseases including cancer.

Characterization of melanoma cells capable of propagating tumors from a single cell.

Questions persist about the nature and number of cells with tumor-propagating capability in different types of cancer, including melanoma. In part, this is because identification and characterization of purified tumorigenic subsets of cancer cells has not been achieved to date. Here, we report tumor formation after injection of single purified melanoma cells derived from three novel mouse models.

Identification of a novel subgroup of melanomas with KIT/cyclin-dependent kinase-4 overexpression.

Although many melanomas harbor either activating mutations in BRAF or NRAS, there remains a substantial, yet little known, group of tumors without either mutation. Here, we used a genomic strategy to define a novel group of melanoma cell lines with co-overexpression of cyclin-dependent kinase 4 (CDK4) and KIT. Although this subgroup lacked any known KIT mutations, they had high phospho-KIT receptor expression, indicating receptor activity.

Epigenetic silencing of novel tumor suppressors in malignant melanoma.

Malignant melanoma is a common and frequently lethal disease. Current therapeutic interventions have little effect on survival, emphasizing the need for a better understanding of the genetic, epigenetic, and phenotypic changes in melanoma formation and progression. We identified 17 genes that were not previously known to be silenced by methylation in melanoma using a microarray-based screen following treatment of melanoma cell lines with the DNA methylation inhibitor 5-Aza-2'-deoxycytidine.

Characterization of melanocyte-specific inducible Cre recombinase transgenic mice.

Conditional Cre-mediated recombination has emerged as a robust method of introducing somatic genetic alterations in an organ-specific manner in the mouse. Here, we generated and characterized mice harboring a 4-hydroxytamoxifen (OHT)-inducible Cre recombinase-estrogen receptor fusion transgene under the control of the melanocyte-specific tyrosinase promoter, designated Tyr::CreER(T2). Cre-mediated recombination was induced in melanocytes in a spatially and temporally controlled manner upon administration of OHT and was documented in embryonic melanoblasts, follicular bulb melanocytes, dermal dendritic melanocytes, epidermal melanocytes of tail skin, and in putative melanocyte stem cells located within the follicular bulge.

Amplification of CDK4 and MDM2 in malignant melanoma.

Amplification of the 12q13-15 region is a common event in several human tumors including liposarcomas, gliomas, and osteosarcomas. We have demonstrated high-level amplification of 12q14 in a subset of uncultured malignant melanomas (3 of 53). High-resolution mapping of the amplicon using quantitative PCR revealed a bipartite amplicon consisting of a primary 50-kb amplicon centered on CDK4 and a secondary amplicon centered on MDM2, without amplification of the intervening 11 Mb of genomic DNA.

Promoter hypermethylation profile of tumor-associated genes p16, p15, hMLH1, MGMT and E-cadherin in oral squamous cell carcinoma.

Aberrant promoter hypermethylation of tumor-associated genes leading to their inactivation is a common event in many cancer types. Using a sensitive restriction-multiplex PCR method, we studied the promoter hypermethylation profile of the p16, p15, hMLH1, MGMT and E-cad genes in oral squamous cell carcinoma (OSCC) of Indians. We analyzed a total of 51 samples for the p15 tumor-suppressor gene and 99 samples for each of the remaining genes.

Genomic instability and tumor-specific alterations in oral squamous cell carcinomas assessed by inter-(simple sequence repeat) PCR.

Purpose: Genomic instability plays a major role in the genesis and progression of tumors, and in the evolution of tumor heterogeneity. To determine the role of genomic instability in the genesis and progression of oral cancer, we assessed the extent of genomic alterations in oral squamous cell carcinomas (OSCCs).

Experimental Design: We used the recently developed inter-(simple sequence repeat) PCR technique to quantitate genomic instability using matched tumor and normal OSCC samples (n = 25).