Androgen receptor blockade promotes response to BRAF/MEK-targeted therapy.

Treatment with therapy targeting BRAF and MEK (BRAF/MEK) has revolutionized care in melanoma and other cancers; however, therapeutic resistance is common and innovative treatment strategies are needed1,2. Here we studied a group of patients with melanoma who were treated with neoadjuvant BRAF/MEK-targeted therapy ( NCT02231775 , n = 51) and observed significantly higher rates of major pathological response (MPR; ≤10% viable tumour at resection) and improved recurrence-free survival (RFS) in female versus male patients (MPR, 66% versus 14%, P = 0.001; RFS, 64% versus 32% at 2 years, P = 0.021). The findings were validated in several additional cohorts2-4 of patients with unresectable metastatic melanoma who were treated with BRAF- and/or MEK-targeted therapy (n = 664 patients in total), demonstrating improved progression-free survival and overall survival in female versus male patients in several of these studies. Studies in preclinical models demonstrated significantly impaired anti-tumour activity in male versus female mice after BRAF/MEK-targeted therapy (P = 0.006), with significantly higher expression of the androgen receptor in tumours of male and female BRAF/MEK-treated mice versus the control (P = 0.0006 and P = 0.0025). Pharmacological inhibition of androgen receptor signalling improved responses to BRAF/MEK-targeted therapy in male and female mice (P = 0.018 and P = 0.003), whereas induction of androgen receptor signalling (through testosterone administration) was associated with a significantly impaired response to BRAF/MEK-targeted therapy in male and female patients (P = 0.021 and P < 0.0001). Together, these results have important implications for therapy.

Obesity is associated with improved progression-free survival in Microsatellite-Instability-High endometrial cancer treated with pembrolizumab.

OBJECTIVES: To determine the clinical predictors of response rate, progression-free survival (PFS), and overall survival (OS) to pembrolizumab in advanced or recurrent, mismatch repair deficient (MMRd) or Microsatellite Instability-High (MSI-H) endometrial adenocarcinomas. METHODS: A retrospective, single institution study was conducted among women with recurrent or advanced MMRd or MSI-H endometrial adenocarcinomas treated with single-agent pembrolizumab at our institution from 2017 to 2021. Logistic regression was used for univariable and multivariable analyses. PFS and OS were estimated using the methods of Kaplan and Meier and modeled via Cox proportional hazards regression. Log-rank test was used for intergroup comparisons based on body mass index (BMI). RESULTS: Among the 44 patients included in the analysis, the median BMI was 32.9 (range 18.5-51.8). Median cycles of pembrolizumab given was 11.5 (range 2-37). Median follow-up was 33 months (range 5-61) with a response rate of 63.6% and stable disease rate of 75%. When stratified by obesity status (BMI≥30), disease control rate was 59.8% in patients with a BMI < 30 and 85.2% in patients with a BMI≥30 patients (p = 0.05). On multivariable analysis, obesity was associated with increased rate of disease control (OR 4.03, 95%CI 1.09, 28) while prior smoking was associated with decreased rate of disease control (OR 0.18, 95%CI 0.03, 0.85). PFS was significantly increased among patients with a BMI≥30 (p = 0.03) but OS was similar (p = 0.5). CONCLUSION: In this retrospective study, obesity is associated with increased rates of disease control and improved PFS in patients treated with pembrolizumab for recurrent or advanced MMRd/MSI-H endometrial adenocarcinomas.

Intervening on impostor phenomenon: prospective evaluation of a workshop for health science students using a mixed-method design.

BACKGROUND: Unaddressed impostor feelings that impede developing interest in science and self-efficacy in conducting research have a dispiriting effect that perpetuates unsatisfactory diversity in the health science workforce when such feelings are experienced more by those historically underrepresented in the workforce. This warrants effective interventions to reduce the impact of impostor feelings and related factors that diminish career resilience. We examined the effects of a 90-minute workshop on impostor perceptions and growth mindset to raise awareness of impostor phenomenon (IP) and develop skills to manage IP successfully for students attending a 10-week summer research experience program. METHODS: Using a convergent mixed-methods design, data were analyzed from 51 racially and ethnically diverse students who participated in an interactive IP workshop. Using students' half-way and final progress reports about their summer experiences and pre- and post-summer online surveys, we identified how the workshop changed awareness of IP and helped students develop coping strategies. RESULTS: Students strongly endorsed the workshop, remarking that its content and personal stories from peers validated their own IP experiences and relieved anxiety by revealing how common the experience was. Many reported applying mindset-changing solutions, including positive self-talk, focusing their thinking on facts about themselves and situation, and grounding themselves firmly against potentially persuasive and confidence-eroding impostor feelings. While students reported end-of-summer impostor feelings at levels similar to before the program, they described being able to manage their feelings better and persist towards goals and challenging tasks. One measure of IP appeared to be addressed through students' activation of a growth mindset, potentially explaining a specific mechanism for intervention. Discrepancies between qualitative responses and quantitative IP measures demand additional work on IP instruments. CONCLUSIONS: A brief, theory-based IP workshop administered by research training programs, including those as short as 10-weeks, can have positive impact on subsequent IP experience and its successful management, with potential long-term impact on retention of a diverse biomedical research workforce.

Endometrial biomarkers in premenopausal women with obesity: an at-risk cohort.

BACKGROUND: Obesity is a well-known risk factor for endometrial cancer, but the mechanisms of obesity-related carcinogenesis are not well defined, particularly for premenopausal women. With the continuing obesity epidemic, increases in the incidence of endometrial cancer and a younger age of diagnosis are often attributed to a hyperestrogenic state created by hormone production in adipose tissue, but significant knowledge gaps remain. The balance of estrogen-responsive signals has not been defined in the endometrium of premenopausal women with obesity, where obesity may not create hyperestrogenism in the context of ovaries being the primary source of estrogen production. Obesity is associated with a state of low-grade, chronic inflammation that can promote tumorigenesis, and it is also known that hormonal changes alter the immune microenvironment of the endometrium. However, limited research has been conducted on endometrial immune-response changes in women who have an increased risk for cancer due to obesity. OBJECTIVE: Endometrial estrogen-regulated biomarkers, previously shown to be dysregulated in endometrial cancer, were evaluated in a cohort of premenopausal women to determine if obesity is associated with differences in the biomarker expression levels, which might reflect an altered risk of developing cancer. The expression of a multiplexed panel of immune-related genes was also evaluated for expression differences related to obesity. STUDY DESIGN: Premenopausal women with a body mass index of ≥30 kg/m2 (n=97) or a body mass index of ≤25 kg/m2 (n=33) were prospectively enrolled in this cross-sectional study, which included the assessment of serum metabolic markers and a timed endometrial biopsy for pathologic evaluation, hormone-regulated biomarker analysis, and immune response gene expression analysis. Medical and gynecologic histories were obtained. Endometrial gene expression markers were also compared across the body mass index groups in a previous cohort of premenopausal women with an inherited cancer risk (Lynch syndrome). RESULTS: In addition to known systemic metabolic differences, histologically normal endometria from women with obesity showed a decrease in gene expression of progesterone receptor (P=.0027) and the estrogen-induced genes retinaldehyde dehydrogenase 2 (P=.008), insulin-like growth factor 1 (P=.016), and survivin (P=.042) when compared with women without obesity. The endometrial biomarkers insulin-like growth factor 1, survivin, and progesterone receptor remained statistically significant in multivariate linear regression models. In contrast, women with obesity and Lynch syndrome had an increased expression of insulin-like growth factor 1 (P=.017). There were no differences in endometrial proliferation, and limited endometrial immune differences were observed. CONCLUSION: When comparing premenopausal women with and without obesity in the absence of endometrial pathology or an inherited cancer risk, the expression of the endometrial biomarkers does not reflect a local hyperestrogenic environment, but it instead reflects a decreased cancer risk profile that may be indicative of a compensated state. In describing premenopausal endometrial cancer risk, it may be insufficient to attribute a high-risk state to obesity alone; further studies are warranted to evaluate individualized biomarker profiles for differences in the hormone-responsive signals or immune response. In patients with Lynch syndrome, the endometrial biomarker profile suggests that obesity further increases the risk of developing cancer.

Prospective phase II trial of levonorgestrel intrauterine device: nonsurgical approach for complex atypical hyperplasia and early-stage endometrial cancer.

BACKGROUND: The incidence of complex atypical hyperplasia and early-stage endometrioid endometrial cancer is increasing, in part owing to the epidemic of obesity, which is a risk factor tightly linked to the development of endometrial hyperplasia and cancer. The standard upfront treatment for complex atypical hyperplasia and early-stage endometrial cancer is hysterectomy. However, nonsurgical treatment of early-stage endometrial neoplasia may be necessary owing to medical comorbidities precluding surgery or desired future fertility. OBJECTIVE: This study aimed to evaluate the efficacy of the levonorgestrel intrauterine device to treat complex atypical hyperplasia and grade 1 endometrioid endometrial carcinoma. STUDY DESIGN: A single-institution, single-arm, phase II study of the levonorgestrel intrauterine device (52 mg levonorgestrel, Mirena) was conducted in patients with complex atypical hyperplasia or grade 1 endometrioid endometrial cancer. The primary endpoint was pathologic response rate at 12 months, including complete or partial response. Quality of life and toxicity were assessed. Molecular analyses for proliferation markers, hormone-regulated genes, and wingless-related integration site pathway activation were performed at baseline and 3 months. RESULTS: A total of 57 patients were treated (21 endometrial cancer, 36 complex atypical hyperplasia). The median age was 48.0 years, and the median body mass index was 45.5 kg/m2. Of the 47 evaluable patients, 12-month response rate was 83% (90% credible interval, 72.7-90.3)-37 were complete responders (8 endometrial cancer; 29 complex atypical hyperplasia), 2 were partial responders (2 endometrial cancer), 3 had stable disease (2 endometrial cancer; 1 complex atypical hyperplasia), and 5 had progressive disease (3 endometrial cancer; 2 complex atypical hyperplasia). After stratification for histology, the response rate was 90.6% for complex atypical hyperplasia and 66.7% for grade 1 endometrioid endometrial cancer. Notably, 4 patients (9.5%) experienced relapse after the initial response. Adverse events were mild, primarily irregular bleeding and cramping. Quality of life was not negatively affected. At 3 months, exogenous progesterone effect was present in 96.9% of responders (31 of 32) vs 25% of nonresponders (2 of 8) (P=.001). Nonresponders had higher baseline proliferation (Ki67) and lower dickkopf homolog 3 gene expression than responders (P=.023 and P=.030). Nonresponders had significantly different changes in secreted frizzled-related protein 1, frizzled class receptor 8, and retinaldehyde dehydrogenase 2 compared with responders. CONCLUSION: The levonorgestrel intrauterine device has a substantial activity in complex atypical hyperplasia and grade 1 endometrioid endometrial cancer, with a modest proportion demonstrating upfront progesterone resistance. Potential biomarkers were identified that may correlate with resistance to therapy; further exploration is warranted.

Improving response to progestin treatment of low-grade endometrial cancer.

OBJECTIVES: This review examines how response rates to progestin treatment of low-grade endometrial cancer can be improved. In addition to providing a brief overview of the pathogenesis of low-grade endometrial cancer, we discuss limitations in the current classification of endometrial cancer and how stratification may be refined using molecular markers to reproducibly identify 'low-risk' cancers which may represent the best candidates for progestin therapy. We also discuss constraints in current approaches to progestin treatment of low-grade endometrial cancer and perform a systematic review of predictive biomarkers. METHODS: PubMed, ClinicalTrials.gov, and Cochrane Library were searched for studies reporting pre-treatment biomarkers associated with outcome in women with low-grade endometrial cancer or endometrial hyperplasia with an intact uterus who received progestin treatment. Studies of fewer than 50 women were excluded. The study protocol was registered in PROSPERO (ID 152374). A descriptive synthesis of pre-treatment predictive biomarkers reported in the included studies was conducted. RESULTS: Of 1908 records reviewed, 19 studies were included. Clinical features such as age or body mass index cannot predict progestin response. Lesions defined as 'low-risk' by FIGO criteria (stage 1A, grade 1) can respond well; however, the reproducibility and prognostic ability of the current histopathological classification system is suboptimal. Molecular markers can be reproducibly assessed, have been validated as prognostic biomarkers, and may inform patient selection for progestin treatment. DNA polymerase epsilon (POLE)-ultramutated tumors and a subset of p53 wild-type or DNA mismatch repair (MMR)-deficient tumors with 'low-risk' features (eg, progesterone and estrogen receptor-positive) may have improved response rates, though this needs to be validated. DISCUSSION: Molecular markers can identify cases which may be candidates for progestin treatment. More work is needed to validate these biomarkers and potentially identify new ones. Predictive biomarkers are anticipated to inform future research into progestin treatment of low-grade endometrial cancer and ultimately improve patient outcomes.

Lymphocyte-specific kinase expression is a prognostic indicator in ovarian cancer and correlates with a prominent B cell transcriptional signature.

OBJECTIVE: To investigate the prognostic and biologic significance of immune-related gene expression in high grade serous ovarian cancer (HGSOC). METHODS: Gene expression dependent survival analyses for a panel of immune related genes were evaluated in HGSOC utilizing The Cancer Genome Atlas (TCGA). Prognostic value of LCK was validated using IHC in an independent set of 72 HGSOC. Prognostic performance of LCK was compared to cytolytic score (CYT) using RNAseq across multiple tumor types. Differentially expressed genes in LCK high samples and gene ontology enrichment were analyzed. RESULTS: High pre-treatment LCK mRNA expression was found to be a strong predictor of survival in a set of 535 ovarian cancers. Patients with high LCK mRNA expression had a longer median progression free survival (PFS) of 29.4 months compared to 16.9 months in those without LCK high expression (p = 0.003), and longer median overall survival (OS) of 95.1 months versus 44.5 months (p = 0.001), which was confirmed in an independent cohort by IHC (p = 0.04). LCK expression was compared to CYT across tumor types available in the TCGA and was a significant predictor of prognosis in HGSOC where CYT was not predictive. Unexpectedly, LCK high samples also were enriched in numerous immunoglobulin-related and other B cell transcripts. CONCLUSIONS: LCK is a better prognostic factor than CYT in ovarian cancer. In HGSOC, LCK high samples were characterized by higher expression of immunoglobulin and B-cell related genes suggesting that a cooperative interaction between tumor infiltrating T and B cells may correlate with better survival in this disease.

Bringing Cancer Prevention Research Competencies to the Classroom.

The field of cancer prevention incorporates research all along the spectrum from basic science studies at the laboratory bench to epidemiology, behavioral sciences, and clinical studies, with the convergence of evidence from these different approaches aimed at implementing public health interventions that reduce the burden of this disease. Due to the necessity of multiple disciplines interacting in order to achieve a public health outcome, traditional discipline-specific training may not be adequately preparing the cancer prevention research workforce. We propose that cancer prevention researchers establish defined professional competencies which will allow them to shape the future directions of the field as well as to collaborate effectively in multidisciplinary teams, disseminate new findings beyond their own scientific circles, and advocate for their implementation for the public good. We previously proposed that these core competencies focus on knowledge of issues in other research fields, interdisciplinary communication, and leadership/teamwork. Here, we describe the reorganization of an existing course to incorporate activities deliberately designed to foster these competencies. We provide details about the course structure, student feedback, and ideas for future versions of this course. We hope this framework will be useful to others who are engaged in the collective effort to develop leaders in the field of cancer prevention research.

Lean Body Weight and Metformin Are Insufficient to Prevent Endometrial Hyperplasia in Mice Harboring Inactivating Mutations in PTEN.

OBJECTIVES: Obesity is a major risk factor for endometrial cancer. We evaluated whether obesity exacerbates progression of endometrial hyperplasia (EH) using the PRCre/+ PTENflox/+ mouse model and examined if the type 2 diabetes drug, metformin, could prevent EH. METHODS: Twenty obese (PRCre/+ PTENflox/+) mice were maintained on a high-fat diet, while 20 lean mice ate a matching low-fat diet. Ten mice from each group received metformin (1,000 mg/day) in drinking water. Mice were euthanized at 26 weeks. Uterine tissue was scored for degree of EH. Immunohistochemical staining for Ki67 was used to evaluate cellular proliferation. Markers of PI3K/AKT/mTOR activity were evaluated by immunohistochemistry using activation-specific antibodies. Serum adiponectin was quantified by ELISA. RESULTS: Obesity had no effect on the extent of EH in (PRCre/+ PTENflox/+) mice. While metformin significantly altered circulating adiponectin levels in obese and lean animals, it had no effect on EH. There were no differences in endometrial proliferation as measured by Ki67 staining. Neither obesity nor metformin altered PI3K/AKT/mTOR activity in these animals. CONCLUSIONS: Weight and metformin did not affect the severity of EH resulting from PTEN inactivation. Alternative mouse models of early endometrial cancer are required for preclinical cancer prevention studies.

Endometrial Cancers With Activating KRas Mutations Have Activated Estrogen Signaling and Paradoxical Response to MEK Inhibition.

OBJECTIVES: The aims of this study were to determine if activating KRas mutation alters estrogen signaling in endometrial cancer (EC) and to explore the potential therapeutic impact of these alterations. METHODS: The Cancer Genome Atlas was queried for changes in estrogen-regulated genes in EC based on KRas mutation status. In vitro studies were conducted to evaluate estrogen receptor α (ERα) phosphorylation changes and related kinase changes in KRas mutant EC cells. The resulting effect on response to MEK inhibition, using trametinib, was evaluated. Immunohistochemistry was performed on KRas mutant and wild-type EC tumors to test estrogen signaling differences. RESULTS: KRas mutant tumors in The Cancer Genome Atlas showed decreased progesterone receptor expression (P = 0.047). Protein analysis in KRas mutant EC cells also showed decreased expression of ERα (P < 0.001) and progesterone receptor (P = 0.001). Although total ERα is decreased in KRas mutant cells, phospho-ERα S118 was increased compared with wild type. Treatment with trametinib in KRas mutant cells increased phospho-ERα S167 and increased expression of estrogen-regulated genes. While MEK inhibition blocked estradiol-stimulated phosphorylation of ERK1/2 and p90RSK in wild-type cells, phospho-ERK1/2 and phospho-p90RSK were substantially increased in KRas mutants. KRas mutant EC tumor specimens showed similar changes, with increased phospho-ERα S118 and phospho-ERα S167 compared with wild-type EC tumors. CONCLUSIONS: MEK inhibition in KRas mutant cells results in activation of ER signaling and prevents the abrogation of signaling through ERK1/2 and p90RSK that is achieved in KRas wild-type EC cells. Combination therapy with MEK inhibition plus antiestrogen therapy may be necessary to improve response rates in patients with KRas mutant EC.

Prospective evaluation of the molecular effects of metformin on the endometrium in women with newly diagnosed endometrial cancer: A window of opportunity study.

OBJECTIVE: Metformin reduces cancer incidence and improves overall survival in diabetic patients. In preclinical studies, metformin decreases endometrial cancer (EC) cell growth by activation of AMPK/mTOR inhibition. We sought to determine the effects of metformin on serum/tumor biomarkers in women with EC. METHODS: In this prospective trial, newly diagnosed EC patients underwent pre-treatment blood draw/endometrial biopsy, were administered oral metformin 850mg daily for ≥7days, and underwent post-treatment blood draw/definitive surgery. Pre- and post- serum analyses were performed. Tumor samples were evaluated for changes in AMPK, PI3K/AKT pathway, proliferation, and apoptosis by immunohistochemistry. RESULTS: Twenty patients completed the trial. Median age and BMI were 57years (range: 27-67) and 34.5kg/m2 (range: 21.9-50.0). Median duration of metformin was 9.5days (range: 7-24). A majority of women had endometrioid adenocarcinomas (90%) and were early stage (85%). After metformin, there were significant decreases in serum IGF-1 (p=0.046), omentin (p=0.007), insulin (p=0.012), C-peptide (p=0.018), and leptin (p=0.0035). Compared to baseline, post-treatment tissue showed decreased phospho-AKT in 18/20 patients (90%, p=0.0002), decreased phospho-S6rp in 14/20 patients (70%, p=0.057), and decreased phospho-p44/42MAPK in 15/18 patients (83.3%, p=0.0038). There was no difference in Ki67, phospho-ACC, or caspase 3. Changes did not correlate with BMI, grade, or KRAS mutation. CONCLUSION: In this prospective window of opportunity study, we demonstrated that relevant serum and molecular changes occur in patients with newly diagnosed EC after a short course of metformin. Ongoing clinical trials will help determine the appropriate role for metformin in the treatment of women with EC.

CGRRF1 as a novel biomarker of tissue response to metformin in the context of obesity.

OBJECTIVE: Obesity-associated hyperestrogenism and hyperinsulinemia contribute significantly to the pathogenesis of endometrial cancer. We recently demonstrated that metformin, a drug long used for treatment of type 2 diabetes, attenuates both insulin- and estrogen-mediated proliferative signaling in the obese rat endometrium. In this study, we sought to identify tissue biomarkers that may prove clinically useful to predict tissue response for both prevention and therapeutic studies. We identified CGRRF1 (cell growth regulator with ring finger domain 1) as a novel metformin-responsive gene and characterized its possible role in endometrial cancer prevention. METHODS: CGRRF1 mRNA expression was evaluated by RT-qPCR in the endometrium of obese and lean rats, and also in normal and malignant human endometrium. CGRRF1 levels were genetically manipulated in endometrial cancer cells, and its effects on proliferation and apoptosis were evaluated by MTT and Western blot. RESULTS: CGRRF1 is significantly induced by metformin treatment in the obese rat endometrium. In vitro studies demonstrate that overexpression of CGRRF1 inhibits endometrial cancer cell proliferation. Analysis of human endometrial tumors reveals that CGRRF1 expression is significantly lower in hyperplasia, Grade 1, Grade 2, Grade 3, MMMT, and UPSC endometrial tumors compared to normal human endometrium (p<0.05), suggesting that loss of CGRRF1 is associated with the presence of disease. CONCLUSION: CGRRF1 represents a novel, reproducible tissue marker of metformin response in the obese endometrium. Furthermore, our preliminary data suggests that up-regulation of CGRRF1 expression may prove clinically useful in the prevention or treatment of endometrial cancer.

Long-term follow-up of levonorgestrel intrauterine device for atypical hyperplasia and early endometrial cancer reveals relapse characterized by immune exhaustion.

BACKGROUND: Nonsurgical treatment options are increasingly needed for endometrial atypical hyperplasia (AH) and endometrioid endometrial cancer (EEC). Despite promising initial response rates, prospective long-term data and determinants for relapse are limited. METHODS: Follow-up data from patients in our prospective phase II trial of LIUD for AH/G1EEC were collected from medical records. Spatial transcriptomics (Nanostring GeoMX digital spatial profiling) with in silico cell type deconvolution and pathway analyses were employed on longitudinal biopsy samples from five patients across pre-treatment, on-treatment, and relapse. RESULTS: Of 43 participants exhibiting initial response to LIUD, 41 had follow-up data. Sixteen (39%) experienced relapse. Clinical factors associated with shorter response duration included younger age, initial diagnosis of G1EEC, lack of response at six months, premenopausal status, and Hispanic ethnicity (p<0.05), but only six-month response status remained a significant predictor in a multivariate model (p=0.023). LIUD increased abundance of NK cells (DMCP-counter score=46.13, FDR=0.004) and cytotoxic lymphocytes (DMCP-counter score=277.67, FDR=0.004), as well as lymphocyte cytotoxicity markers PRF1 (log2FC=1.62, FDR=0.025) and GZMA (log2FC=2.47, FDR=0.008). NK cells were reduced at relapse (DMCP-counter score=-55.96, FDR=0.02). Immune-related pathways (IFNα-response and TGFß-signaling) were enriched at relapse (FDR<0.05). IDO1 expression, reflecting immune exhaustion, was upregulated at relapse (FDR<0.05). CONCLUSIONS: Upfront resistance and relapse after initial response to LIUD for AH/G1EEC impacts nearly half of patients, remaining a major hurdle for non-surgical treatment of AH/G1EEC. Molecular studies evaluating longitudinal biopsies from a small cohort implicate immune mechanisms at relapse, including reversal of progestin-related immunomodulation and increased immune exhaustion.

Mitochondrial defects and metabolic vulnerabilities in Lynch syndrome-associated MSH2-deficient endometrial cancer.

Lynch syndrome (LS) is defined by inherited mutations in DNA mismatch repair genes, including MSH2, and carries 60% lifetime risk of developing endometrial cancer (EC). Beyond hypermutability, specific mechanisms for LS-associated endometrial carcinogenesis are not well understood. Here, we assessed the effects of MSH2 loss on EC pathogenesis using a novel mouse model (PR-Cre Msh2 flox/flox , abbreviated Msh2KO), primary cell lines established from this model, human tissues, and human EC cell lines with isogenic MSH2 knockdown. Beginning at eight months of age, 30% of Msh2KO mice exhibited endometrial atypical hyperplasia (AH), a precancerous lesion. At 12 to 16 months of age, 47% of Msh2KO mice exhibited either AH or ECs with histologic features similar to human LS-related ECs. Transcriptomic profiling of EC from Msh2KO mice revealed a transcriptomic signature for mitochondrial dysfunction. Studies in vitro and in vivo revealed mitochondrial dysfunction based upon two mechanisms: marked mitochondrial content reduction, along with pronounced disruptions to the integrity of retained mitochondria. Human LS-related ECs also exhibited mitochondrial content reduction compared with non-LS-related ECs. Functional studies revealed metabolic reprogramming of MSH2-deficient EC cells in vitro , including reduced oxidative phosphorylation and increased susceptibility to glycolysis suppression. We are the first to identify mitochondrial dysfunction and metabolic disruption as a consequence of MSH2 deficiency-related EC. Mitochondrial and metabolic aberrations should be evaluated as novel biomarkers for endometrial carcinogenesis or risk stratification and could serve as targets for cancer interception in women with LS. Significance: This is the first study to report mitochondrial dysfunction contributing to MSH2-deficient endometrial cancer development, identifying a noncanonical pathway for MSH2 deficient carcinogenesis, which also imparts vulnerability to metabolic targeting.

Molecular, Metabolic, and Subcellular Mapping of the Tumor Immune Microenvironment via 3D Targeted and Non-Targeted Multiplex Multi-Omics Analyses.

Most platforms used for the molecular reconstruction of the tumor-immune microenvironment (TIME) of a solid tumor fail to explore the spatial context of the three-dimensional (3D) space of the tumor at a single-cell resolution, and thus lack information about cell-cell or cell-extracellular matrix (ECM) interactions. To address this issue, a pipeline which integrated multiplex spatially resolved multi-omics platforms was developed to identify crosstalk signaling networks among various cell types and the ECM in the 3D TIME of two FFPE (formalin-fixed paraffin embedded) gynecologic tumor samples. These platforms include non-targeted mass spectrometry imaging (glycans, metabolites, and peptides) and Stereo-seq (spatial transcriptomics) and targeted seqIF (IHC proteomics). The spatially resolved imaging data in a two- and three-dimensional space demonstrated various cellular neighborhoods in both samples. The collection of spatially resolved analytes in a voxel (3D pixel) across serial sections of the tissue was also demonstrated. Data collected from this analytical pipeline were used to construct spatial 3D maps with single-cell resolution, which revealed cell identity, activation, and energized status. These maps will provide not only insights into the molecular basis of spatial cell heterogeneity in the TIME, but also novel predictive biomarkers and therapeutic targets, which can improve patient survival rates.

Molecular pathogenesis of endometrial cancers in patients with Lynch syndrome.

BACKGROUND: The authors hypothesized that Lynch syndrome (LS)-associated endometrial cancer (EC) develops from morphologically normal endometrium that accumulates enough molecular changes to progress through a continuum of hyperplasia to carcinoma, similar to sporadic EC. The primary objective of the current study was to determine whether LS-associated EC involves progression through a preinvasive lesion. The secondary objective was to identify molecular changes that contribute to endometrial carcinogenesis in patients with LS. METHODS: Women with a confirmed mismatch repair gene mutation for LS who were undergoing a prophylactic or therapeutic hysterectomy were eligible. Cases and controls were matched for EC and hyperplasia based preferentially on age and histology. Mutation status of phosphatidylinositol 3-kinase (PIK3CA); KRAS; AKT; LKB1; catenin (cadherin-associated protein), beta 1, 88kDa (CTNNB1); and phosphatase and tensin homolog (PTEN) protein loss was assessed. RESULTS: Concurrent complex atypical hyperplasia (CAH) was found in EC in 11 cases of LS (39.3%) and 21 sporadic cases (46.6%). Loss of PTEN expression was common in both sporadic (69%) and LS-associated EC (86.2%). There was no significant difference noted with regard to the frequency of KRAS mutations in cases of sporadic EC (10.3%) compared with LS-associated EC (3.4%). AKT and LKB1 mutations were rarely observed. Mutations in PIK3CA and CTNNB1 occurred more frequently in cases of sporadic EC compared with LS-associated EC. CONCLUSIONS: Hyperplasia, particularly CAH, is part of the preinvasive spectrum of disease in LS-associated EC, as indicated by the presence of complex hyperplasia and CAH in cases of LS. Although loss of PTEN is common in both LS and sporadic EC cases, there was a lack of additional mutations in LS-associated EC cases. This suggests that in the context of the mismatch repair defects in LS, fewer additional molecular changes are required to progress from preinvasive lesions to cancer.

Chemopreventive effects of metformin on obesity-associated endometrial proliferation.

OBJECTIVE: Obesity is a significant contributing factor to endometrial cancer risk. We previously demonstrated that estrogen-induced endometrial proliferation is enhanced in the context of hyperinsulinemia and insulin resistance. In this study, we investigate whether pharmacologic agents that modulate insulin sensitivity or normalize insulin levels will diminish the proliferative response to estrogen. STUDY DESIGN: Zucker fa/fa obese rats and lean controls were used as models of hyperinsulinemia and insulin resistance. Insulin levels were depleted in ovariectomized rats following treatment with streptozotocin, or modulated by metformin treatment. The number of BrdU-incorporated cells, estrogen-dependent proliferative and antiproliferative gene expression, and activation of mTOR and ERK1/2 MAPK signaling were studied. A rat normal endometrial cell line RENE1 was used to evaluate the direct effects of metformin on endometrial cell proliferation and gene expression in vitro. RESULTS: Streptozotocin lowered circulating insulin levels in obese rats and decreased the number of BrdU-labeled endometrial cells even in the presence of exogenous estrogen. Treatment with the insulin-sensitizing drug metformin attenuated estrogen-dependent proliferative expression of c-myc and c-fos in the obese rat endometrium compared to untreated controls and was accompanied by inhibition of phosphorylation of the insulin and IGF1 receptors (IRß/IGF1R) and ERK1/2. In vitro studies indicated metformin inhibited RENE1 proliferation in a dose-dependent manner. CONCLUSION: These findings suggest that drugs that modulate insulin sensitivity, such as metformin, hinder estrogen-mediated endometrial proliferation. Therefore, these drugs may be clinically useful for the prevention of endometrial cancer in obese women.

TIME for Bugs: The Immune Microenvironment and Microbes in Precancer.

Major advances in our understanding of the tumor immune microenvironment (TIME) in established cancer have been made, including the influence of host-intrinsic (host genomics) and -extrinsic factors (such as diet and the microbiome) on treatment response. Nonetheless, the immune and microbiome milieu across the spectrum of precancerous tissue and early neoplasia is a growing area of interest. There are emerging data describing the contribution of the immune microenvironment and microbiota on benign and premalignant tissues, with opportunities to target these factors in cancer prevention and interception. Throughout this review, we provide rationale for not only the critical need to further elucidate the premalignant immune microenvironment, but also for the utility of pharmacologic and lifestyle interventions to alter the immune microenvironment of early lesions to reverse carcinogenesis. Novel research methodologies, such as implementing spatial transcriptomics and proteomics, in combination with innovative sampling methods will advance precision targeting of the premalignant immune microenvironment. Additional studies defining the continuum of immune and microbiome evolution, which emerges in parallel with tumor development, will provide novel opportunities for cancer interception at the earliest steps in carcinogenesis.

Targeting Nrf2 with the triterpenoid CDDO-imidazolide attenuates cigarette smoke-induced emphysema and cardiac dysfunction in mice.

Chronic obstructive pulmonary disease (COPD), which comprises emphysema and chronic bronchitis resulting from prolonged exposure to cigarette smoke (CS), is a major public health burden with no effective treatment. Emphysema is also associated with pulmonary hypertension, which can progress to right ventricular failure, an important cause of morbidity and mortality among patients with COPD. Nuclear erythroid 2 p45 related factor-2 (Nrf2) is a redox-sensitive transcription factor that up-regulates a battery of antioxidative genes and cytoprotective enzymes that constitute the defense against oxidative stress. Recently, it has been shown that patients with advanced COPD have a decline in expression of the Nrf2 pathway in lungs, suggesting that loss of this antioxidative protective response is a key factor in the pathophysiological progression of emphysema. Furthermore, genetic disruption of Nrf2 in mice causes early-onset and severe emphysema. The present study evaluated whether the strategy of activation of Nrf2 and its downstream network of cytoprotective genes with a small molecule would attenuate CS-induced oxidative stress and emphysema. Nrf2(+/+) and Nrf2(-/-) mice were fed a diet containing the potent Nrf2 activator, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), while being exposed to CS for 6 months. CDDO-Im significantly reduced lung oxidative stress, alveolar cell apoptosis, alveolar destruction, and pulmonary hypertension in Nrf2(+/+) mice caused by chronic exposure to CS. This protection from CS-induced emphysema depended on Nrf2, as Nrf2(-/-) mice failed to show significant reduction in alveolar cell apoptosis and alveolar destruction after treatment with CDDO-Im. These results suggest that targeting the Nrf2 pathway during the etiopathogenesis of emphysema may represent an important approach for prophylaxis against COPD.