Evaluation of the Spanish-Language Cancer Educational Webinar Series "Vamos a educarnos contra el cáncer" with the RE-AIM Framework.

The COVID-19 pandemic disrupted healthcare for patients with chronic diseases, including cancer. Barriers to healthcare increased, especially for racial and ethnic minorities. While many institutions developed webinars to educate community members, few webinars used a community-based participatory approach, employed a theory-based engagement design, and were evaluated. This manuscript reports the outcomes of "Vamos a educarnos contra el cáncer," a 2021 webinar series. Monthly educational webinars were conducted in Spanish on cancer-related topics. The presentations were delivered by Spanish-speaking content experts from different organizations. Webinars were conducted using the video conferencing platform Zoom. Polls were launched during the webinar to collect data and evaluate each webinar. The RE-AIM model of reach, effectiveness, adoption, implementation, and maintenance was used to evaluate the series. The SAS Analytics Software was used for analysis and data management. Two hundred ninety-seven people participated with over 3000 views of the webinar recordings (Reach); 90% rated the sessions as good or excellent (Effectiveness); 86% agreed to adopt or improve a cancer-related behavior, and 90% reported willingness to adopt or improve a cancer-related action for someone else (Adoption); 92% reported feeling engaged (Implementation). The series has produced a resource library, manual of operations, and agreement of the Hispanic/Latino Cancer Community Advisory Board (CAB) to continue the webinar series in the future (Maintenance). Overall, these results highlight the impact of this webinar series and provide a standard approach to planning, delivering, and evaluating webinars as a strategy for cancer prevention and control in a culturally appropriate manner.

Approaches for describing and communicating overall uncertainty in toxicity characterizations: U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) as a case study.

Single point estimates of human health hazard/toxicity values such as a reference dose (RfD) are generally used in chemical hazard and risk assessment programs for assessing potential risks associated with site- or use-specific exposures. The resulting point estimates are often used by risk managers for regulatory decision-making, including standard setting, determination of emission controls, and mitigation of exposures to chemical substances. Risk managers, as well as stakeholders (interested and affected parties), often have limited information regarding assumptions and uncertainty factors in numerical estimates of both hazards and risks. Further, the use of different approaches for addressing uncertainty, which vary in transparency, can lead to a lack of confidence in the scientific underpinning of regulatory decision-making. The overarching goal of this paper, which was developed from an invited participant workshop, is to offer five approaches for presenting toxicity values in a transparent manner in order to improve the understanding, consideration, and informed use of uncertainty by risk assessors, risk managers, and stakeholders. The five approaches for improving the presentation and communication of uncertainty are described using U.S. Environmental Protection Agency's (EPA's) Integrated Risk Information System (IRIS) as a case study. These approaches will ensure transparency in the documentation, development, and use of toxicity values at EPA, the Agency for Toxic Substances and Disease Registry (ATSDR), and other similar assessment programs in the public and private sector. Further empirical testing will help to inform the approaches that will work best for specific audiences and situations.

Melanocyte and melanoma cell activation by calprotectin.

Calprotectin, a heterodimer of S100A8 and S100A9, is a proinflammatory cytokine released from ultraviolet radiation-exposed keratinocytes. Calprotectin binds to Toll-like receptor 4, the receptor for advanced glycation end-products, and extracellular matrix metalloproteinase inducer on target cells to stimulate migration. Melanocytes and melanoma cells produce little if any calprotectin, but they do express receptors for the cytokine. Thus, keratinocyte-derived calprotectin has the potential to activate melanocytes and melanoma cells within the epidermis in a paracrine manner. We examined the ability of calprotectin to stimulate proliferation and migration in normal human melanocytes and melanoma cells in vitro. We first showed, by immunofluorescence and quantitative RT-PCR, that the melanocytic cells employed expressed a calprotectin receptor, the receptor for advanced end-products. We then demonstrated that calprotectin significantly enhanced proliferation, migration, and Matrigel invasion in both normal human melanocytes and melanoma cells. Thus, calprotectin is one of the numerous paracrine factors released by ultraviolet radiation-exposed keratinocytes that may promote melanomagenesis and is a potential target for melanoma prevention or therapy.

Cell-state transitions regulated by SLUG are critical for tissue regeneration and tumor initiation.

Perturbations in stem cell activity and differentiation can lead to developmental defects and cancer. We use an approach involving a quantitative model of cell-state transitions in vitro to gain insights into how SLUG/SNAI2, a key developmental transcription factor, modulates mammary epithelial stem cell activity and differentiation in vivo. In the absence of SLUG, stem cells fail to transition into basal progenitor cells, while existing basal progenitor cells undergo luminal differentiation; together, these changes result in abnormal mammary architecture and defects in tissue function. Furthermore, we show that in the absence of SLUG, mammary stem cell activity necessary for tissue regeneration and cancer initiation is lost. Mechanistically, SLUG regulates differentiation and cellular plasticity by recruiting the chromatin modifier lysine-specific demethylase 1 (LSD1) to promoters of lineage-specific genes to repress transcription. Together, these results demonstrate that SLUG plays a dual role in repressing luminal epithelial differentiation while unlocking stem cell transitions necessary for tumorigenesis.

Ultraviolet radiation and the slug transcription factor induce proinflammatory and immunomodulatory mediator expression in melanocytes.

Despite extensive investigation, the precise contribution of the ultraviolet radiation (UVR) component of sunlight to melanoma etiology remains unclear. UVR induces keratinocytes to secrete proinflammatory and immunomodulatory mediators that promote inflammation and skin tumor development; expression of the slug transcription factor in keratinocytes is required for maximal production of these mediators. In the present studies we examined the possibility that UVR-exposed melanocytes also produce proinflammatory mediators and that Slug is important in this process. Microarray studies revealed that both UVR exposure and Slug overexpression altered transcription of a variety of proinflammatory mediators by normal human melanocytes; some of these mediators are also known to stimulate melanocyte growth and migration. There was little overlap in the spectra of cytokines produced by the two stimuli. However IL-20 was similarly induced by both stimuli and the NFκB pathway appeared to be important in both circumstances. Further exploration of UVR-induced and Slug-dependent pathways of cytokine induction in melanocytes may reveal novel targets for melanoma therapy.

Slug expression during melanoma progression.

Slug (Snai2), a member of the Snail family of zinc finger transcription factors, plays a role in the epithelial-to-mesenchymal transformation (EMT) that occurs during melanocyte emigration from the neural crest. A role for Slug in the EMT-like loss of cell adhesion and increased cell motility exhibited during melanoma progression has also been proposed. Our immunohistochemical studies of melanoma arrays, however, revealed that Slug expression was actually higher in nevi than in primary or metastatic melanomas. Moreover, Slug expression in melanomas was not associated with decreased expression of E-cadherin, the canonical Slug target in EMT. Comparisons of endogenous Slug and E-cadherin expression in cultured normal human melanocytes and melanoma cell lines supported our immunohistochemical findings. Expression of exogenous Slug in melanocytes and melanoma cells in vitro, however, suppressed E-cadherin expression, enhanced N-cadherin expression, and stimulated cell migration and invasion. Interestingly, both in tumors and cultured cell lines, there was a clear relationship between expression of Slug and MITF, a transcription factor known to regulate Slug expression during development. Taken together, our findings suggest that Slug expression during melanomagenesis is highest early in the process and that persistent Slug expression is not required for melanoma progression. The precise role of Slug in melanomagenesis remains to be elucidated and may be related to its interactions with other drivers of EMT, such as Snail.

Transgenic insulin-like growth factor-1 stimulates activation of COX-2 signaling in mammary glands.

Studies show that elevated insulin-like growth factor-1 (IGF-1) levels are associated with an increased risk of breast cancer; however, mechanisms through which IGF-1 promotes mammary tumorigenesis in vivo have not been fully elucidated. To assess the possible involvement of COX-2 signaling in the pro-tumorigenic effects of IGF-1 in mammary glands, we used the unique BK5.IGF-1 mouse model in which transgenic (Tg) mice have significantly increased incidence of spontaneous and DMBA-induced mammary cancer compared to wild type (WT) littermates. Studies revealed that COX-2 expression was significantly increased in Tg mammary glands and tumors, compared to age-matched WTs. Consistent with this, PGE(2) levels were also increased in Tg mammary glands. Analysis of expression of the EP receptors that mediate the effects of PGE(2) showed that among the four G-protein-coupled receptors, EP3 expression was elevated in Tg glands. Up-regulation of the COX-2/PGE(2) /EP3 pathway was accompanied by increased expression of VEGF and a striking enhancement of angiogenesis in IGF-1 Tg mammary glands. Treatment with celecoxib, a selective COX-2 inhibitor, caused a 45% reduction in mammary PGE(2) levels, attenuated the influx of mast cells and reduced vascularization in Tg glands. These findings indicate that the COX-2/PGE(2) /EP3 signaling pathway is involved in IGF-1-stimulated mammary tumorigenesis and that COX-2-selective inhibitors may be useful in the prevention or treatment of breast cancer associated with elevated IGF-1 levels in humans. © 2011 Wiley Periodicals, Inc.

Developmental stage determines estrogen receptor alpha expression and non-genomic mechanisms that control IGF-1 signaling and mammary proliferation in mice.

Insulin like growth factor-1 (IGF-1) stimulates increased proliferation and survival of mammary epithelial cells and also promotes mammary tumorigenesis. To study the effects of IGF-1 on the mammary gland in vivo, we used BK5.IGF-1 transgenic (Tg) mice. In these mice, IGF-1 overexpression is controlled by the bovine keratin 5 promoter and recapitulates the paracrine exposure of breast epithelium to stromal IGF-1 that is seen in women. Studies have shown that BK5.IGF-1 Tg mice are more susceptible to mammary tumorigenesis than wild-type littermates. Investigation of the mechanisms underlying increased mammary cancer risk, reported here, revealed that IGF-1 preferentially activated the PI3K/Akt pathway in glands from prepubertal Tg mice, resulting in increased cyclin D1 expression and hyperplasia. However, in glands from postpubertal Tg mice, a pathway switch occurred and activation of the Ras/Raf/MAPK pathway predominated, without increased cyclin D1 expression or proliferation. We further showed that in prepubertal Tg glands, signaling was mediated by formation of an ERα/IRS-1 complex, which activated IRS-1 and directed signaling via the PI3K/Akt pathway. Conversely, in postpubertal Tg glands, reduced ERα expression failed to stimulate formation of the ERα/IRS-1 complex, allowing signaling to proceed via the alternate Ras/Raf/MAPK pathway. These in vivo data demonstrate that changes in ERα expression at different stages of development direct IGF-1 signaling and the resulting tissue responses. As ERα levels are elevated during the prepubertal and postmenopausal stages, these may represent windows of susceptibility during which increased IGF-1 exposure maximally enhances breast cancer risk.

P53 genotype as a determinant of ER expression and tamoxifen response in the MMTV-Wnt-1 model of mammary carcinogenesis.

Clinical studies show that estrogen receptor-α (ER) expressing tumors tend to have better prognosis, respond to antiestrogen therapy and have wild-type p53. Conversely, tumors with inactivating mutations in p53 tend to have worse outcomes and to be ER-negative and unresponsive to antihormone treatment. Previous studies from our laboratory have shown that p53 regulates ER expression transcriptionally, by binding the ER promoter and forming a complex with CARM1, CBP, c-Jun, RNA polymerase II and Sp1. In this study, the MMTV-Wnt-1 transgenic mouse model was used to demonstrate that p53 regulation of ER expression and function is not solely an in vitro phenomenon, but it is also operational in mammary tumorigenesis in vivo. The expression of ER and the ability to respond to tamoxifen were determined in mammary tumors arising in p53 wild type (WT) or p53 heterozygous (HT) animals carrying the Wnt-1 transgene. In p53 WT mice, development of ER-positive tumors was delayed by tamoxifen treatment, while tumors arising in p53 HT mice had significantly reduced levels of ER and were not affected by tamoxifen. P53 null tumors were also found in the p53 HT mice and these tumors were ER-negative. ER expression was upregulated in mouse mammary tumor cell lines following transfection with WT p53 or treatment with doxorubicin. These data demonstrate that p53 regulates ER expression in vivo, and affects response to tamoxifen. Results also provide an explanation for the concordant relationship between these prognostic proteins in human breast tumors.

The skinny on Slug.

The zinc finger transcription factor Slug (Snai2) serves a wide variety of functions in the epidermis, with roles in skin development, hair growth, wound healing, skin cancer, and sunburn. Slug is expressed in basal keratinocytes and hair follicles where it is important in maintaining epidermal homeostasis. Slug also helps coordinate the skin response to exogenous stimuli. Slug is rapidly induced by a variety of growth factors and injurious agents and Slug controls, directly or indirectly, a variety of keratinocyte responses, including changes in differentiation, adhesion, motility, and production of inflammatory mediators. Slug thus modulates the interactions of the keratinocyte with its environment and with surrounding cells. The function of Slug in the epidermis appears to be distinct from that of the closely related Snail transcription factor.

Transcriptional regulation of estrogen receptor-alpha by p53 in human breast cancer cells.

Estrogen receptor alpha (ER) and p53 are critical prognostic indicators in breast cancer. Loss of functional p53 is correlated with poor prognosis, ER negativity, and resistance to antiestrogen treatment. Previously, we found that p53 genotype was correlated with ER expression and response to tamoxifen in mammary tumors arising in mouse mammary tumor virus-Wnt-1 transgenic mice. These results lead us to hypothesize that p53 may regulate ER expression. To test this, MCF-7 cells were treated with doxorubicin or ionizing radiation, both of which stimulated a 5-fold increase in p53 expression. ER expression was also increased 4-fold over a 24-h time frame. In cells treated with small interfering RNA (siRNA) targeting p53, expression of both p53 and ER was significantly reduced (>60%) by 24 h. Induction of ER by DNA-damaging agents was p53 dependent as either ionizing radiation or doxorubicin failed to up-regulate ER after treatment with p53-targeting siRNA. To further investigate whether p53 directly regulates transcription of the ER gene promoter, MCF-7 cells were transiently transfected with a wild-type (WT) p53 expression vector along with a luciferase reporter containing the proximal promoter of ER. In cells transfected with WT p53, transcription from the ER promoter was increased 8-fold. Chromatin immunoprecipitation assays showed that p53 was recruited to the ER promoter along with CARM1, CBP, c-Jun, and Sp1 and that this multifactor complex was formed in a p53-dependent manner. These data show that p53 regulates ER expression through transcriptional control of the ER promoter, accounting for their concordant expression in human breast cancer.