Plasma hyaluronan (HA) increases systemically in type 2 diabetes (T2D) and the HA synthesis inhibitor, 4-Methylumbelliferone, has been proposed to treat the disease. However, HA is also implicated in normal physiology. Therefore, we generated a Hyaluronan Synthase 2 transgenic mouse line, driven by a tet-response element promoter to understand the role of HA in systemic metabolism. To our surprise, adipocyte-specific overproduction of HA leads to smaller adipocytes and protects mice from high-fat-high-sucrose-diet-induced obesity and glucose intolerance. Adipocytes also have more free glycerol that can be released upon beta3 adrenergic stimulation. Improvements in glucose tolerance were not linked to increased plasma HA. Instead, an HA-driven systemic substrate redistribution and adipose tissue-liver crosstalk contributes to the systemic glucose improvements. In summary, we demonstrate an unexpected improvement in glucose metabolism as a consequence of HA overproduction in adipose tissue, which argues against the use of systemic HA synthesis inhibitors to treat obesity and T2D.

Despite advances in surgery, chemotherapy, and radiation, there are limited treatment options for advanced head and neck squamous cell carcinoma (HNSCC) and survival remains very poor. Therefore, effective therapies are desperately needed. Recently, selective exploitation of DNA damage and replication stress responses has become a novel approach for cancer treatment. Wee1 kinase and Rad51 recombinase are two proteins involved in regulating replication stress and homologous recombination repair in cancer cells. In this study, we investigated the combined effect of Rad51 inhibitor (B02) and Wee1 inhibitor (AZD1775) in vitro and in vivo in various HNSCC cell lines. Clonogenic survival assays demonstrated that B02 synergized with AZD1775 in vitro in all HNSCC cell lines tested. The synergy between these drugs was associated with forced CDK1 activation and reduced Chk1 phosphorylation leading to induction of excessive DNA damage and replication stress, culminating in aberrant mitosis and apoptosis. Our results showed that elevated Rad51 mRNA expression correlated with worse survival in HNSCC patients with HPV-positive tumors. The combination of B02 and AZD1775 significantly inhibited tumor growth in vivo in mice bearing HPV-positive HNSCC tumors as compared to HPV-negative HNSCC. This differential sensitivity appears to be linked to HPV-positive tumors having more in vivo endogenous replication stress owing to transformation by E6 and E7 oncogenes. Furthermore, addition of B02 radiosensitized the HPV-negative HNSCC tumors in vitro and in vivo. In conclusion, our data implicate that a novel rational combination with Rad51 and Wee1 inhibitors holds promise as synthetic lethal therapy, particularly in high-risk HPV-positive HNSCC.

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Background Skin scarring can occur after punch biopsies, prohibiting their routine use especially in the central face. Objectives This paper describes a scarless 0.33mm in diameter skin microbiopsy for molecular analysis of skin. Methods This is a single center, randomized, prospective study with fifteen subjects receiving no biopsy, or biopsy on the left or right nasolabial fold. Six blinded raters assessed subject photos at baseline, one month, and three months post biopsy to evaluate for a visualized scar. Patient and Observer Scar Assessment Scale (POSAS) was completed. Additionally, biopsies from various skin regions of body along with arm skin after treatment with a single Erbium-YAG laser were processed for molecular analysis. Results All subjects did not exhibit scar formation based on evaluation of photographs and patient feedback. There was no mark at the biopsy site seven days post-procedure. Optical Coherence Tomography showed a complete closing of the biopsy-punch wound 48-hours post-biopsy. One-month post-biopsy, photography reviewers were unable to identify a scar, on average, 90% of the time at three-month follow-up. Microbiopsies from various anatomical regions were successfully extracted for histology, electron microscopy and gene expression analysis. Selected skin rejuvenation markers in the biopsies from Erbium-YAG treated forearm skin resulted in significant gene upregulation in extracellular matrix molecules following one-month post treatment compare to untreated skin. Conclusions A core micro-biopsy of 0.33mm can be extracted reproducibly for histological, ultrastructural and gene expression analysis without scarring. This allows repeated sampling for assessment of skin treatments and diseases including aesthetics and wound healing progress.

Purpose: CDDP based chemotherapy is a first-line treatment for patients with advanced head and neck squamous cell carcinomas (HNSCCs), despite a high rate of treatment failures, acquired resistance and subsequent aggressive behavior. The purpose of this study was to delineate the mechanism of CDDP resistance and metastasis in HNSCC. We investigated the role of NRF2 pathway activation as a driven event for tumor progression and metastasis of HNSCC. Experimental Design: Human HNSCC cell lines that are highly resistant to CDDP were generated. Clonogenic survival assays and a mouse model of oral cancer were used to examine the impact of NRF-2 activation in vitro and in vivo on CDDP sensitivity and development of metastasis. Western blotting, immunostaining, whole exome sequencing, single cell transcriptomic and epigenomic profiling platforms were performed to dissect clonal evolution and molecular mechanisms Results: Implantation of CDDP resistant HNSCC cells into the tongues of nude mice resulted in a very high rate of distant metastases. The CDDP resistant cells had significantly higher expression of NRF2 pathway genes in the presence of newly acquired KEAP1 mutations, or via epigenomic activation of target genes. Knockdown of NRF2 or restoration of the wtKEAP1 genes re-sensitized resistant cells to CDDP and decreased distant metastasis. Finally, treatment with inhibitor of GLS1, a NRF2 target gene, alleviated CDDP resistance. Conclusions: CDDP resistance and development of distant metastasis are associated with dysregulated and epigenetically reprogrammed KEAP1-NRF2 signaling pathway. A strategy targeting KEAP1/NRF2 pathway or glutamine metabolism deserves further clinical investigation in patients with CDDP resistant head and neck tumors.