GRP78 haploinsufficiency suppresses acinar-to-ductal metaplasia, signaling, and mutant Kras-driven pancreatic tumorigenesis in mice.

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease in critical need of new therapeutic strategies. Here, we report that the stress-inducible 78-kDa glucose-regulated protein (GRP78/HSPA5), a key regulator of endoplasmic reticulum homeostasis and PI3K/AKT signaling, is overexpressed in the acini and PDAC of Pdx1-Cre;KrasG12D/+;p53f/+ (PKC) mice as early as 2 mo, suggesting that GRP78 could exert a protective effect on acinar cells under stress, as during PDAC development. The PKC pancreata bearing wild-type Grp78 showed detectable PDAC by 3 mo and rapid subsequent tumor growth. In contrast, the PKC pancreata bearing a Grp78f/+ allele (PKC78f/+ mice) expressing about 50% of GRP78 maintained normal sizes during the early months, with reduced proliferation and suppression of AKT, S6, ERK, and STAT3 activation. Acinar-to-ductal metaplasia (ADM) has been identified as a key tumor initiation mechanism of PDAC. Compared with PKC, the PKC78f/+ pancreata showed substantial reduction of ADM as well as pancreatic intraepithelial neoplasia-1 (PanIN-1), PanIN-2, and PanIN-3 and delayed onset of PDAC. ADM in response to transforming growth factor α was also suppressed in ex vivo cultures of acinar cell clusters isolated from mouse pancreas bearing targeted heterozygous knockout of Grp78 (c78f/+ ) and subjected to 3D culture in collagen. We further discovered that GRP78 haploinsufficiency in both the PKC78f/+ and c78f/+ pancreata leads to reduction of epidermal growth factor receptor, which is critical for ADM initiation. Collectively, our studies establish a role for GRP78 in ADM and PDAC development.

Mechanism of cytokinesis failure in ovarian cystadenomas with defective BRCA1 and P53 pathways.

We previously described an in vitro model in which serous ovarian cystadenomas were transfected with SV40 large T antigen, resulting in loss of RB and P53 functions and thus mimicking genetic defects present in early high-grade serous extra-uterine Müllerian (traditionally called high-grade serous ovarian) carcinomas including those associated with the BRCA1 mutation carrier state. We showed that replicative aging in this cell culture model leads to a mitotic arrest at the spindle assembly checkpoint. Here we show that this arrest is due to a reduction in microtubule anchoring that coincides with decreased expression of the BUB1 kinase and of the phosphorylated form of its substrate, BUB3. The ensuing prolonged mitotic arrest leads to cohesion fatigue resulting in cell death or, in cells that recover from this arrest, in cytokinesis failure and polyploidy. Down-regulation of BRCA1 to levels similar to those present in BRCA1 mutation carriers leads to increased and uncontrolled microtubule anchoring to the kinetochore resulting in overcoming the spindle assembly checkpoint. Progression to anaphase under those conditions is associated with formation of chromatin bridges between chromosomal plates due to abnormal attachments to the kinetochore, significantly increasing the risk of cytokinesis failure. The dependence of this scenario on accelerated replicative aging can, at least in part, account for the site specificity of the cancers associated with the BRCA1 mutation carrier state, as epithelia of the mammary gland and of the reproductive tract are targets of cell-nonautonomous consequences of this carrier state on cellular proliferation associated with menstrual cycle progressions.

Maf1 is a novel target of PTEN and PI3K signaling that negatively regulates oncogenesis and lipid metabolism.

Maf1 was initially identified as a transcriptional repressor of RNA pol III-transcribed genes, yet little is known about its other potential target genes or its biological function. Here, we show that Maf1 is a key downstream target of PTEN that drives both its tumor suppressor and metabolic functions. Maf1 expression is diminished with loss of PTEN in both mouse models and human cancers. Consistent with its role as a tumor suppressor, Maf1 reduces anchorage-independent growth and tumor formation in mice. PTEN-mediated changes in Maf1 expression are mediated by PTEN acting on PI3K/AKT/FoxO1 signaling, revealing a new pathway that regulates RNA pol III-dependent genes. This regulatory event is biologically relevant as diet-induced PI3K activation reduces Maf1 expression in mouse liver. We further identify lipogenic enzymes as a new class of Maf1-regulated genes whereby Maf1 occupancy at the FASN promoter opposes SREBP1c-mediated transcription activation. Consistent with these findings, Maf1 inhibits intracellular lipid accumulation and increasing Maf1 expression in mouse liver abrogates diet-mediated induction of lipogenic enzymes and triglycerides. Together, these results establish a new biological role for Maf1 as a downstream effector of PTEN/PI3K signaling and reveal that Maf1 is a key element by which this pathway co-regulates lipid metabolism and oncogenesis.

The sex hormone system in carriers of BRCA1/2 mutations: a case-control study.

BACKGROUND: Penetrance for breast cancer, ovarian cancer, or both in carriers of BRCA1/BRCA2 mutations is disproportionately high. Sex hormone dysregulation and altered end-organ hormone sensitivity might explain this organ-specific penetrance. We sought to identify differences in hormone regulation between carriers of BRCA1/2 and women who are negative for BRCA1/2 mutations. METHODS: We assessed endometrial thickness for each menstrual cycle day (as an index of hormone regulation) in 393 scans from 228 women in the UK Familial Ovarian Cancer Screening Study (UK FOCSS) known to carry either mutation and 1573 scans from 754 women known to be negative for the mutations. To quantify differences in endometrial thickness we focused on days 10-14 and days 21-26, and calculated the area under the curve. We then compared serum oestradiol and progesterone titres during these days of the menstrual cycle in the same groups. Follicular and luteal oestradiol and progesterone serum titres were grouped into quartiles and odds ratios were calculated with logistic regression. FINDINGS: Follicular phase endometrial thickness of carriers of the mutations adjusted for age and day of the menstrual cycle was higher (odds ratio [OR] 1·11, 95% CI 1·03-1·20; p=0·0063) and luteal phase endometrial thickness lower (0·90, 0·83-0·98; p=0·027) than for women negative for the mutations. Median luteal phase titres of progesterone were 121% higher (p=0·00037) in carriers than in women negative for the mutations, and for oestradiol were 33% higher (p=0·007)-ie, 59% of carriers had concentrations of serum progesterone that would have been in the top quartile of concentrations in the control group (OR 8·0, 95% CI 2·1-52·57; p=0·008). INTERPRETATION: Carriers of BRCA1/BRCA2 mutations are exposed to higher titres of oestradiol and progesterone-known risk-factors for breast cancer. Higher titres of oestradiol in carriers are compatible with this hormone having a role in ovarian carcinogenesis in such women. Our findings could not be explained by differential contraceptive pill use.

Neurotropism of SARS-CoV-2: A Pathological Examination of Neurosurgical Specimens.

BACKGROUND AND OBJECTIVES: Neurological manifestations may occur in more than 80% of patients hospitalized with COVID-19 infection, including severe disruptions of the central nervous system (CNS), such as strokes, encephalitis, or seizures. Although the primary pathophysiological mechanism for the effects of COVID-19 in CNS remains unknown, evidence exists for both direct injury from neuroinvasion and indirect effects from disruptions in systemic inflammatory and coagulation pathways. In this study, we analyzed CNS tissue from living patients to better understand these processes. METHODS: With institutional review board approval and patient consent, samples that would be otherwise discarded from patients with active or recent (within 6 days of surgery) COVID-19 infection undergoing neurosurgical intervention were collected and tested for the presence of SARS-CoV-2 using immunohistochemistry, in situ hybridization, electron microscopy, and reverse transcription polymerase chain reaction. RESULTS: Five patients with perioperative mild-to-moderate COVID-19 infection met inclusion criteria (2 male, 3 female; mean age 38.8 ± 13.5 years). Neurosurgical diagnoses included a glioblastoma, a ruptured arteriovenous malformation, a ruptured posterior inferior cerebellar artery aneurysm, a middle cerebral artery occlusion, and a hemorrhagic pontine cavernous malformation. Samples analyzed included the frontal lobe cortex, olfactory nerve, arteriovenous malformation/temporal lobe parenchyma, middle cerebral artery, cerebellum, and cavernous malformation/brainstem parenchyma. Testing for the presence of SARS-CoV-2 was negative in all samples. CONCLUSION: The CNS is likely not a significant viral reservoir during mild-to-moderate COVID-19 infection, although direct neuroinvasion is not definitively excluded. Additional testing to help elucidate the relative contributions of direct and indirect pathways for CNS injury from COVID is warranted.

Natural Killer Cell Dysfunction in Premenopausal BRCA1 Mutation Carriers: A Potential Mechanism for Ovarian Carcinogenesis.

BACKGROUND: Tissue-specificity for fimbrial fallopian tube ovarian carcinogenesis remains largely unknown in BRCA1 mutation carriers. We aimed to assess the cell autonomous and cell-nonautonomous implications of a germline BRCA1 mutation in the context of cancer immunosurveillance of CD3- CD56+ natural killer (NK) cells. METHODS: Premenopausal BRCA1 mutation carriers versus age-matched non-carriers were compared. Daily urinary 5ß-pregnanediol levels were used to determine progesterone metabolomics across an ovarian cycle. Using peripherally acquired NK cells the cell-mediated cytotoxicity of tumor targets (OVCAR-3, K-562) was determined using live cellular impedance (xCELLigence®) and multicolor flow cytometry. Hypoxia-inducible factor 1-alpha (HIF-1α) immunohistochemistry of cancer-free fallopian tube specimens allowed a comparison of proximal versus distal portions. Utilizing these findings the role of environmental factors relevant to the fimbrial fallopian tube (progesterone, hypoxia) on NK cell functional activity were studied in an ovarian phase-specific manner. RESULTS: BRCA1 mutation carriers demonstrate a differential progesterone metabolome with a phase-specific reduction of peripheral NK cell functional activity. Progesterone exposure further impairs NK cell-mediated cytotoxicity in a dose-dependent manner, which is reversed with the addition of mifepristone (1.25 µM). The fimbrial fallopian tube demonstrated significantly higher HIF-1α staining, particularly in BRCA1 mutation carriers, reflecting a site-specific 'hypoxic niche'. Exposure to hypoxic conditions (1% O2) can further impair tumor cytotoxicity in high-risk carriers. CONCLUSIONS: Phase-specific differential NK cell activity in BRCA1 mutation carriers, either systemically or locally, may favor site-specific pre-invasive carcinogenesis. These cumulative effects across a reproductive lifecycle in high-risk carriers can have a detrimental effect further supporting epidemiological evidence for ovulation inhibition.

The endoplasmic reticulum stress marker, glucose-regulated protein-78 (GRP78) in visceral adipocytes predicts endometrial cancer progression and patient survival.

OBJECTIVE: Currently, accurately identifying endometrial cancer patients at high risk for recurrence remains poor. To ascertain if changes in the endoplasmic reticulum (ER) stress marker, glucose-regulated-protein-78 (GRP78) can serve as a prognosticator in endometrial cancer, we examined GRP78 expression in patient samples to determine its association with clinical outcome. METHODS: A retrospective cohort study was conducted in endometrial cancer patients. Archived specimens of visceral adipocytes and paired endometrial tumors were analyzed by immunohistochemistry for GRP78 and another ER stress marker, C/EBP homologous protein (CHOP). Expression of these markers was correlated with clinico-pathological information and outcomes. RESULTS: GRP78 expression in visceral adipocytes was detected in 95% of the 179 endometrial cancer patients with analyzable visceral adipocytes. Within individual samples, 24% of adipocytes (range, 0-90%, interquartile range 18%-38%) exhibited GRP78 expression. High visceral adipocyte GRP78 expression positively correlated with advanced-stage disease (p=0.007) and deep myometrial invasion (p=0.004). High visceral adipocyte GRP78 expression was significantly associated with decreased disease-free survival (DFS) in multivariate analyses (hazard ratio 2.88, 95% CI 1.37-6.04, p=0.005). CHOP expression paralleled the GRP78 expression in adipocytes (r=0.55, p<0.001) and in the tumor (p=0.018). CONCLUSIONS: Our study demonstrates that the ER stress markers, GRP78 and CHOP, are elevated in endometrial cancer patients. Furthermore, GRP78 expression levels in visceral adipocytes from these patients were significantly correlated to disease stage and patient survival. Our results demonstrate, for the first time, that the GRP78 levels in endometrial cancer patients may be a prognosticator and aid with clinical risk stratification and focused surveillance.

Embryological Insights into the Origin of Epithelial Cancers of the Female Reproductive Tract.

The embryology of the female reproductive organs is reviewed focusing on aspects relevant to the histogenesis of reproductive neoplasms. The evidence reviewed suggests that (1) there is no embryological link between the ovarian surface epithelium and the coelomic epithelium; (2) the ovarian surface epithelium is not composed of pluripotent cells that readily differentiate into various components of the reproductive tract before or after birth; (3) there is no embryological link between the ovarian surface epithelium and the Müllerian ducts, from which internal female reproductive organs other than the ovaries, including the endocervix, endometrium, and fallopian tubes, are derived; and (4) there is an embryological link between the Müllerian ducts and the renal collecting system, perhaps accounting for clear cell differentiation in some gynecological malignancies. Implications for our understanding of the origin of the tumors historically classified as ovarian epithelial neoplasms are discussed.

GRP78 Inhibitor YUM70 Suppresses SARS-CoV-2 Viral Entry, Spike Protein Production and Ameliorates Lung Damage.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the COVID-19 pandemic, has given rise to many new variants with increased transmissibility and the ability to evade vaccine protection. The 78-kDa glucose-regulated protein (GRP78) is a major endoplasmic reticulum (ER) chaperone that has been recently implicated as an essential host factor for SARS-CoV-2 entry and infection. In this study, we investigated the efficacy of YUM70, a small molecule inhibitor of GRP78, to block SARS-CoV-2 viral entry and infection in vitro and in vivo. Using human lung epithelial cells and pseudoviral particles carrying spike proteins from different SARS-CoV-2 variants, we found that YUM70 was equally effective at blocking viral entry mediated by original and variant spike proteins. Furthermore, YUM70 reduced SARS-CoV-2 infection without impacting cell viability in vitro and suppressed viral protein production following SARS-CoV-2 infection. Additionally, YUM70 rescued the cell viability of multi-cellular human lung and liver 3D organoids transfected with a SARS-CoV-2 replicon. Importantly, YUM70 treatment ameliorated lung damage in transgenic mice infected with SARS-CoV-2, which correlated with reduced weight loss and longer survival. Thus, GRP78 inhibition may be a promising approach to augment existing therapies to block SARS-CoV-2, its variants, and other viruses that utilize GRP78 for entry and infection.

Alterations in Brca1 expression in mouse ovarian granulosa cells have short-term and long-term consequences on estrogen-responsive organs.

Incessant menstrual cycle activity, uninterrupted by either pregnancy or oral contraceptive use, is the most important risk factor for sporadic ovarian cancer. Menstrual cycle progression is partly controlled by steroid hormones such as estrogens and others that are secreted by the ovarian granulosa cells. We showed earlier that mice carrying a homozygous granulosa cell-specific knockout of Brca1, the homolog of BRCA1 that is associated with familial ovarian cancer predisposition in humans, develop benign epithelial tumors in their reproductive tract. These tumors are driven, at least in part, by a prolongation of the proestrus phase of the estrus cycle (equivalent to the follicular phase of the menstrual cycle) in Brca1 mutant mice, resulting in prolonged unopposed estrogen stimulation. Mutant mice synchronized in proestrus also showed increased circulating estradiol levels, but the possibility that this change also has a role in tumor predisposition was not investigated. We sought to determine whether these changes in hormonal stimulation result in measurable changes in tissues targeted by estrogen outside the ovary. Here we show that mice carrying a Brca1 mutation in their ovarian granulosa cells show increased endometrial proliferation during proestrus, implying that the effects of Brca1 inactivation on estrogen stimulation have short-term consequences, at least on this target organ. We further show that mutant mice develop increased femoral trabecular thickness and femoral length, which are well-known consequences of chronic estrogen stimulation. Estrogen biosynthesis by granulosa cells was increased not only in mice carrying a homozygous Brca1 mutation, but also in heterozygous mutants mimicking the mutational status in granulosa cells of human BRCA1 mutation carriers. The results suggest that human germline BRCA1 mutations, although associated with increased cancer risk, may also have beneficial consequences, such as increased bone strength, that may have contributed to the maintenance of mutated BRCA1 alleles in the human gene pool.

Role of BRCA1 in controlling mitotic arrest in ovarian cystadenoma cells.

Cancers that develop in BRCA1 mutation carriers are usually near tetraploid/polyploid. This led us to hypothesize that BRCA1 controls the mitotic checkpoint complex, as loss of such control could lead to mitotic errors resulting in tetraploidy/polyploidy and subsequent aneuploidy. We used an in vitro system mimicking premalignant conditions, consisting of cell strains derived from the benign counterparts of serous ovarian carcinomas (cystadenomas) and expressing SV40 large T antigen, conferring the equivalent of a p53 mutation. We previously showed that such cells undergo one or several doublings of their DNA content, as they age in culture and approach the phenomenon of in vitro crisis. Here, we show that such increase in DNA content reflects a cell cycle arrest possibly at the anaphase promoting complex, as evidenced by decreased BrdU incorporation and increased expression of the mitotic checkpoint complex. Down-regulation of BRCA1 in cells undergoing crisis leads to activation of the anaphase promoting complex and resumption of growth kinetics similar to those seen in cells before they reach crisis. Cells recovering from crisis after BRCA1 down-regulation become multinucleated, suggesting that reduced BRCA1 expression may lead to initiation of a new cell cycle without completion of cytokinesis. This is the first demonstration that BRCA1 controls a physiological arrest at the M phase apart from its established role in DNA damage response, a role that could represent an important mechanism for acquisition of aneuploidy during tumor development. This may be particularly relevant to cancers that have a near tetraploid/polyploid number of chromosomes.

Antiprogestins reduce epigenetic field cancerization in breast tissue of young healthy women.

BACKGROUND: Breast cancer is a leading cause of death in premenopausal women. Progesterone drives expansion of luminal progenitor cells, leading to the development of poor-prognostic breast cancers. However, it is not known if antagonising progesterone can prevent breast cancers in humans. We suggest that targeting progesterone signalling could be a means of reducing features which are known to promote breast cancer formation. METHODS: In healthy premenopausal women with and without a BRCA mutation we studied (i) estrogen and progesterone levels in saliva over an entire menstrual cycle (n = 20); (ii) cancer-free normal breast-tissue from a control population who had no family or personal history of breast cancer and equivalently from BRCA1/2 mutation carriers (n = 28); triple negative breast cancer (TNBC) biopsies and healthy breast tissue taken from sites surrounding the TNBC in the same individuals (n = 14); and biopsies of ER+ve/PR+ve stage T1-T2 cancers and healthy breast tissue taken from sites surrounding the cancer in the same individuals (n = 31); and (iii) DNA methylation and DNA mutations in normal breast tissue (before and after treatment) from clinical trials that assessed the potential preventative effects of vitamins and antiprogestins (mifepristone and ulipristal acetate; n = 44). RESULTS: Daily levels of progesterone were higher throughout the menstrual cycle of BRCA1/2 mutation carriers, raising the prospect of targeting progesterone signalling as a means of cancer risk reduction in this population. Furthermore, breast field cancerization DNA methylation signatures reflective of (i) the mitotic age of normal breast epithelium and (ii) the proportion of luminal progenitor cells were increased in breast cancers, indicating that luminal progenitor cells with elevated replicative age are more prone to malignant transformation. The progesterone receptor antagonist mifepristone reduced both the mitotic age and the proportion of luminal progenitor cells in normal breast tissue of all control women and in 64% of BRCA1/2 mutation carriers. These findings were validated by an alternate progesterone receptor antagonist, ulipristal acetate, which yielded similar results. Importantly, mifepristone reduced both the TP53 mutation frequency as well as the number of TP53 mutations in mitotic-age-responders. CONCLUSIONS: These data support the potential usage of antiprogestins for primary prevention of poor-prognostic breast cancers. TRIAL REGISTRATION: Clinical trial 1 Mifepristone treatment prior to insertion of a levonorgestrel releasing intrauterine system for improved bleeding control - a randomized controlled trial, clinicaltrialsregister.eu, 2009-009014-40 ; registered on 20 July 2009. Clinical trial 2 The effect of a progesterone receptor modulator on breast tissue in women with BRCA1 and 2 mutations, clinicaltrials.gov, NCT01898312 ; registered on 07 May 2013. Clinical trial 3 A pilot prevention study of the effects of the anti- progestin Ulipristal Acetate (UA) on surrogate markers of breast cancer risk, clinicaltrialsregister.eu, 2015-001587-19 ; registered on 15 July 2015.

Pathological characteristics of BRCA-associated breast cancers in Hispanics.

The immunophenotype of BRCA-associated breast cancer has been studied in predominantly non-Hispanic whites (NHW). We evaluated the pathological characteristics of BRCA-associated invasive breast cancer in Hispanics. A case-control study was conducted on breast cancers from Hispanic and NHW women who enrolled in an IRB-approved registry and underwent BRCA gene analysis. BRCA negative controls (41 Hispanic, 39 NHW) were matched on age and ethnicity to BRCA positive cases (39 Hispanic, 35 NHW). A tissue array was constructed to characterize the expression of estrogen receptor (ER), progesterone receptor (PR), HER2, Ki-67 and p53 by immunohistochemistry. Mean age at diagnosis was 37.1 years (range 24-59) for Hispanics (80% with Mexican ancestry) and 40.1 years (range 21-63) for NHW (P = 0.03). Hispanic BRCA1 cases were more likely than BRCA negative controls to have tumors that were ER-negative (P < 0.001) and PR-negative (P = 0.001), had higher levels of Ki-67 (P = 0.001) and p53 expression, and lower levels of HER2 overexpression. When stratified by genes, there were no significant differences in expression of ER, Ki-67, HER2, and p53 by ethnicity among mutation carriers. However, a significantly higher proportion of BRCA-positive Hispanics had PR-negative tumors compared to BRCA-positive NHW (80 vs. 57%, OR = 2.9, 95% CI 1.0-8.1, P = 0.04). Hispanic BRCA-associated breast cancers were found to have the unique immunophenotype associated with BRCA mutations; however, there was a trend toward a difference in PR expression among Hispanic BRCA1 and BRCA2 cases. Additional research on the molecular mechanisms involved in the loss of PR in this population is warranted as it could have important implications for the treatment and prevention of breast cancer in Hispanics.

A Phosphotyrosine Switch in Estrogen Receptor ß Is Required for Mouse Ovarian Function.

The two homologous estrogen receptors ERα and ERß exert distinct effects on their cognate tissues. Previous work from our laboratory identified an ERß-specific phosphotyrosine residue that regulates ERß transcriptional activity and antitumor function in breast cancer cells. To determine the physiological role of the ERß phosphotyrosine residue in normal tissue development and function, we investigated a mutant mouse model (Y55F) whereby this particular tyrosine residue in endogenous mouse ERß is mutated to phenylalanine. While grossly indistinguishable from their wild-type littermates, mutant female mice displayed reduced fertility, decreased ovarian follicular cell proliferation, and lower progesterone levels. Moreover, mutant ERß from female mice during superovulation is defective in activating promoters of its target genes in ovarian tissues. Thus, our findings provide compelling genetic and molecular evidence for a role of isotype-specific ERß phosphorylation in mouse ovarian development and function.

Endoplasmic reticulum chaperone GRP78/BiP is critical for mutant Kras-driven lung tumorigenesis.

Lung cancer is the leading cause of cancer mortality worldwide and KRAS is the most commonly mutated gene in lung adenocarcinoma (LUAD). The 78-kDa glucose-regulated protein GRP78/BiP is a key endoplasmic reticulum chaperone protein and a major pro-survival effector of the unfolded protein response (UPR). Analysis of the Cancer Genome Atlas database and immunostain of patient tissues revealed that compared to normal lung, GRP78 expression is generally elevated in human lung cancers, including tumors bearing the KRASG12D mutation. To test the requirement of GRP78 in human lung oncogenesis, we generated mouse models containing floxed Grp78 and Kras Lox-Stop-Lox G12D (KrasLSL-G12D) alleles. Simultaneous activation of the KrasG12D allele and knockout of the Grp78 alleles were achieved in the whole lung or selectively in lung alveolar epithelial type 2 cells known to be precursors for adenomas that progress to LUAD. Here we report that GRP78 haploinsufficiency is sufficient to suppress KrasG12D-mediated lung tumor progression and prolong survival. Furthermore, GRP78 knockdown in human lung cancer cell line A427 (KrasG12D/+) leads to activation of UPR and apoptotic markers and loss of cell viability. Our studies provide evidence that targeting GRP78 represents a novel therapeutic approach to suppress mutant KRAS-mediated lung tumorigenesis.

Non-Surgical Cancer Risk Reduction in BRCA1 Mutation Carriers: Disabling the Remote Control.

Women-specific cancers are a major health issue, particularly those associated with the BRCA1 germline mutation carrier state, which include triple-negative basal breast carcinomas and high-grade serous ovarian carcinomas (referred to as extra-uterine Müllerian carcinomas). Whereas many chronic diseases can currently be prevented (e.g., cardiovascular diseases), no recent tangible progress was made in cancer prevention of BRCA1 mutation carriers apart from surgical resections of at-risk organs. This lack of progress is largely due to (1) poor understanding of the initiating events triggered by known risk factors in the development of these cancers, (2) the fact that current preventive measures rely on evidence obtained from adjuvant breast cancer treatment that fail to protect against poor prognostic cancers, and (3) problems with using cancer incidence in high-risk women as an ethically justifiable endpoint in cancer prevention trials. Here, we propose that cancer predisposition in BRCA1 mutation carriers is driven, at least in part, by cell-nonautonomous mechanisms (i.e., driven by consequences of this carrier state on hormonal and other systemic factors controlled in organs other than those that are cancer-prone) and that biomarkers of epigenomic reprogramming, hypothesized to be a direct consequence of such cell-nonautonomous mechanisms, are attractive as intermediate surrogate endpoints to assess the efficacy of cancer risk-reducing strategies targeting these mechanisms.

Clinicopathological significance of endoplasmic reticulum stress proteins in ovarian carcinoma.

Epithelial ovarian cancer (EOC) is a leading cause of cancer-related mortality in the United States due to the late-stage disease at diagnosis. Overexpression of GRP78 and PDI following endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) promote growth and invasion in cancer. To identify novel prognostic biomarkers in EOC, here we determined the expression of ER stress-associated proteins (GRP78, ATF6 and PERK) and correlated with clinical outcome in EOC. Tissue microarray (TMA) samples from 415 tissues collected from three cancer centers (UM, USC, and KCCRI) were used to assess the expression levels of ER-associated proteins using immunohistochemistry (IHC). We observed that the expression levels of GRP78 (p < 0.0001), ATF6 (p < 0.0001), and PERK (p < 0.0001) were significantly increased in specimens of EOC compared to normal tissues, including in the serous subtype (p < 0.0001). Previously we reported that high expression of PDI correlated with poor patient survival in EOC. Here we showed that overexpression of GRP78 and PDI protein expression correlated with poor patient survival (p = 0.03), while low expression of combined GRP78 and PDI correlated with better survival (p = 0.01) in high-grade serous. The increased expression of ER stress-associated proteins in EOC suggests a role for ER stress and the UPR in EOC. More importantly, our results demonstrate that GRP78 and PDI are potential biomarkers for EOC and could be used as dual prognostic markers.

HOXA methylation in normal endometrium from premenopausal women is associated with the presence of ovarian cancer: a proof of principle study.

DNA methylation of polycomb group target (PCGT) genes is an early step in carcinogenesis and could potentially be assayed to determine cancer risk prediction. To assess whether methylation changes in PCGT genes in normal tissue is able to predict the presence of cancer, we studied HOXA gene methylation in normal endometrium from premenopausal ovarian cancer patients and age-matched healthy controls without ovarian cancer. DNA methylation of HOXA9 and HOXA11 genes in normal endometrium was associated with ovarian cancer in an initial test set and this was subsequently confirmed in independent validation sample sets. The overall risk of ovarian cancer was increased 12.3-fold by high HOXA9 methylation for all stages, and 14.8-fold for early stage ovarian cancers, independent of age, phase of the menstrual cycle and histology of the cancer. The results of this proof of principle study demonstrate the potential to detect ovarian cancer via analysis of normal endometrial cells and provide insight into the possible contribution of this novel approach in ovarian cancer risk prediction and prevention.

The cell of origin of ovarian epithelial tumours.

Although it is widely believed that ovarian epithelial tumours arise in the coelomic epithelium that covers the ovarian surface, it has been suggested that they could instead arise from tissues that are embryologically derived from the Müllerian ducts. This article revisits this debate by discussing recent epidemiological and molecular biological findings as well as evidence based on histopathological observations of surgical specimens from individuals with familial ovarian cancer predisposition. Morphological, embryological, and molecular biological characteristics of ovarian epithelial tumours that must be accounted for in formulating a theory about their cell of origin are reviewed, followed by comments about the ability of these two hypotheses to account for each of these characteristics. An argument is made that primary ovarian epithelial tumours, fallopian tube carcinomas, and primary peritoneal carcinomas are all Müllerian in nature and could therefore be regarded as a single disease entity. Although a substantial proportion of cancers currently regarded as of primary ovarian origin arise in the fimbriated end of the fallopian tube, this site cannot account for all of these tumours, some of which are most likely derived from components of the secondary Müllerian system.