KLF4/GKLF normally functions in differentiating epithelial cells, but also acts as a transforming oncogene in vitro.To examine the role of this zinc finger protein in skin, we expressed the wild-type human allele from inducible and constitutive promoters. When induced in basal keratinocytes, KLF4 rapidly abolished the distinctive properties of basal and parabasal epithelial cells. KLF4 caused a transitory apoptotic response and the skin progressed through phases of hyperplasia and dysplasia. By 6 weeks, lesions exhibited nuclear KLF4 and other morphologic and molecular similarities to squamous cell carcinoma in situ. p53 determined the patch size sufficient to establish lesions, as induction in a mosaic pattern produced skin lesions only when p53 was deficient. Compared with p53 wild-type animals, p53 hemizygous animals had early onset of lesions and a pronounced fibrovascular response that included outgrowth of subcutaneous sarcoma. A KLF4-estrogen receptor fusion protein showed tamoxifendependent nuclear localization and conditional transformation in vitro. The results suggest that KLF4 can function in the nucleus to induce squamous epithelial dysplasia, and indicate roles for p53 and epithelialmesenchymal signaling in these early neoplastic lesions.
Gli family members mediate constitutive Hedgehog signaling in the common skin cancer, basal cell carcinoma (BCC). Snail/Snai1 is rapidly induced by Gli1 in vitro, and is coexpressed with Gli1 in human hair follicles and skin tumors. In the current study, we generated a dominant-negative allele of Snail, SnaZFD, composed of the zinc-finger domain and flanking sequence. In promoter-reporter assays, SnaZFD blocked the activity of wild-type Snail on the E-cadherin promoter. Snail loss-of-function mediated by SnaZFD or by one of several short hairpin RNAs inhibited transformation of RK3E epithelial cells by Gli1. Conversely, enforced expression of Snail promoted transformation in vitro by Gli1, but not by other genes that were tested, including Notch1, ErbB2, and N-Ras. As observed for Gli1, wild-type Snail repressed E-cadherin in RK3E cells and induced blebbing of the cytoplasmic membrane. Induction of a conditional Gli1 transgene in the basal keratinocytes of mouse skin led to rapid upregulation of Snail transcripts and to cell proliferation in the interfollicular epidermis. Established Gli1-induced skin lesions exhibited molecular similarities to BCC, including loss of E-cadherin. The results identify Snail as a Gli1-inducible effector of transformation in vitro, and an early Gli1-responsive gene in the skin.
Innovative strategies are needed to reduce the hypertension epidemic among African Americans. Reach Out was a faith-collaborative, mobile health, randomized, pilot intervention trial of four mobile health components to reduce high blood pressure (BP) compared to usual care. It was designed and tested within a community-based participatory research framework among African Americans recruited and randomized from churches in Flint, Michigan. The purpose of this pilot study was to assess the feasibility of the Reach Out processes. Feasibility was assessed by willingness to consent (acceptance of randomization), proportion of weeks participants texted their BP readings (intervention use), number lost to follow-up (retention), and responses to postintervention surveys and focus groups (acceptance of intervention). Of the 425 church members who underwent BP screening, 94 enrolled in the study and 73 (78%) completed the 6-month outcome assessment. Median age was 58 years, and 79% were women. Participants responded with their BPs on an average of 13.7 (SD = 10.7) weeks out of 26 weeks that the BP prompts were sent. All participants reported satisfaction with the intervention. Reach Out, a faith-collaborative, mobile health intervention was feasible. Further study of the efficacy of the intervention and additional mobile health strategies should be considered.
Host responses to tumor cells include tumor suppressing or promoting mechanisms. We sought to detail the effect of Hedgehog (Hh) pathway inhibition on the composition of the mammary tumor immune portfolio. We hypothesized that Hh signaling mediates a crosstalk between breast cancer cells and macrophages that dictates alternative polarization of macrophages and consequently supports a tumor-promoting microenvironment. We used an immunocompetent, syngeneic mouse mammary cancer model to inhibit Hh signaling with the pharmacological inhibitor, Vismodegib. Using molecular and functional assays, we identified that Hedgehog (Hh) signaling mediates a molecular crosstalk between mammary cancer cells and macrophages that culminates in alternative polarization of macrophages. We carried out an unbiased kinomics and genomics assessment to unravel changes in global kinomic and gene signatures impacted by Hh signaling. Our investigations reveal that in an immunocompetent mammary cancer model, the administration of Vismodegib led to changes in the portfolio of tumor-infiltrating immune cells. This was characterized by a marked reduction in immune-suppressive innate and adaptive cells concomitant with an enrichment of cytotoxic immune cells. Breast cancer cells induce M2 polarization of macrophages via a crosstalk mediated by Hh ligands that alters critical kinomic and genomic signatures. Macrophage depletion improved the benefit of Hedgehog inhibition on eliciting an immunogenic, pro-inflammatory profile. We define a novel role for Hh signaling in disabling anti-tumor immunity. Inhibition of Hh signaling presents with dual advantages of tumor cell-targeting as well as re-educating a dysfunctional tumor microenvironment.
The mental health consequences of the Covid-19 pandemic are particularly relevant in African American communities, as African-Americans have been disproportionately impacted by the disease, yet they are traditionally less engaged in mental health treatment compared to other racial groups. Using the state of Michigan as an example, we describe the social and psychological consequences of the pandemic on African-American communities in the United States, highlighting community members' concerns about contracting the disease, fears of racial bias in testing and treatment, experiences of sustained grief and loss, and retraumatization of already traumatized communities. Further, we describe the multi-level community-wide approaches that have been used thus far to mitigate adverse mental health outcomes within our local African-American communities. Keywordscommunity mental health; trauma; racial disparities; coronavirus; population health African-American communities in the state of Michigan have been disproportionately impacted by the Covid-19 pandemic. Despite making up only 13% of Michigan's population, African-Americans account for 32% of confirmed cases and 41% of pandemic related-deaths (Michigan Department of Health and Human Services, 2020). In Michigan's primarily African-American communities, more than 10% of Covid-19 cases end in death (Michigan Department of Health and Human Services, 2020). A disease that was initially thought to mostly impact older adults and the chronically infirmed has now become a national scourge, devastating African-American communities across the U.S.From a mental health perspective, the pandemic has heightened fear in a segment of the population that already faces significant barriers to mental health treatment. Despite having rates of mental illness similar to Whites, African-Americans experience significant
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