Two pandemics intertwined around one patient: Interstitial pneumonia as the first presentation of HIV/AIDS, be it Pneumocystis jirovecii, cytomegalovirus, SARS-CoV2 or all?-A case report.

Concerns have been mounting regarding the underdiagnosis of HIV among respiratory co-infections associated with the COVID-19 pandemic. The delay in recognizing HIV/AIDS may be attributed to the similarities in clinical, laboratory (lymphopenia) and imaging presentations, which are typical for advanced AIDS but could also be indicative of a COVID-19 infection. Herein, we present a case of a 38-year-old ultraorthodox Jew with a late diagnosis of AIDS in the context of COVID-19 infection. This occurred after several months of recurrent respiratory infections compounded by SARS-COV 2 infection, during which no HIV testing was conducted. As a result, a cascade of various opportunistic infections ensued, leading to an extended hospitalization period, ultimately culminating in the patient's demise despite receiving optimal treatment.

MRI prediction of neoadjuvant chemotherapy response is equivalent in patients with or without mammographic calcifications: a step towards adapting surgical approach?

OBJECTIVES: Current surgical policy recommends comprehensive excision of tumorous calcifications in breast cancer patients following neoadjuvant chemotherapy (NAC) regardless of MRI outcomes, despite MRI defining tumor response superior to mammography. The current study examines MRI prediction of response in tumors with vs without calcifications, using post-NAC surgical pathology as the standard of reference. METHODS: Retrospective analysis of 114 NAC patients between 2011 and 2018 including demographics, mammography, 3 T-MRI, and pathology compared two sub-groups: without (n = 62) or with (n = 52) mammographic calcifications. In the calcification cohort, the mammographic extent of calcifications and MRI enhancement overlapped. MRI prediction of response to NAC was correlated with pathology. Two-tailed paired T and Fisher's exact tests and Cohen's kappa coefficient were applied for analysis. RESULTS: There was no significant difference between the two sub-groups regarding demographics. Tumors demonstrated equivalent features regarding size, lymph node involvement, and DCIS component. ER-negative/HER2-positive tumors more commonly exhibited calcifications (33% n = 17 calcified vs 13% n = 8 non-calcified; p < 0.05); triple negative pathology rarely calcified (6% n = 3 calcified vs 33% n = 20 non-calcified; p < 0.05). NME was more common with calcifications (62% n = 32 calcified vs 29% n = 18 non-calcified; p < 0.05) and mass enhancement without (90% n = 56 non-calcified vs 81% n = 42 calcified; p < 0.05). Both groups responded similarly to NAC (pCR = 37% non-calcified vs 38% calcified); response on MRI equally correlated with pathology (69% both subgroups; p = 0.988). CONCLUSION: We propose utilizing post-NAC MRI findings rather than mammography in planning surgery, as MRI prediction is independent of the presence or absence of calcifications. Prospective studies to evaluate this approach are warranted. KEY POINTS: • No difference was found in demographic, clinical, pathology, or imaging characteristics between patients with or without tumoral calcifications on mammography prior to neoadjuvant chemotherapy. • Residual mammographic calcifications are inadequate predictors of residual invasive disease. MRI accurately recognized complete response and correctly correlated with post-treatment surgical pathology in 69% of patients, regardless of the presence or absence of mammographic calcifications. • We propose utilizing post-NAC MRI findings rather than mammography in planning post-NAC surgery, as MRI prediction of response is independent of the presence or absence of calcifications.

Macrophages Upregulate Estrogen Receptor Expression in the Model of Obesity-Associated Breast Carcinoma.

Breast cancer (BC) and obesity are two heterogeneous conditions with a tremendous impact on health. BC is the most commonly diagnosed neoplasm and the leading cause of cancer-related mortality among women, and the prevalence of obesity in women worldwide reaches pandemic proportions. Obesity is a significant risk factor for both incidence and worse prognosis in estrogen receptor positive (ER+) BC. Yet, the mechanisms underlying the association between excess adiposity and increased risk/therapy resistance/poorer outcome of ER+, but not ER-negative (ER-), BC are not fully understood. Tumor-promoting action of obesity, predominantly in ER + BC patients, is often attributed to the augmented production of estrogen in 'obese' adipose tissue. However, in addition to the estrogen production, expression levels of ER represent a key determinant in hormone-driven breast tumorigenesis and therapy response. Here, utilizing in vitro and in vivo models of BC, we show that macrophages, whose adverse activation by obesogenic substances is fueled by heparanase (extracellular matrix-degrading enzyme), are capable of upregulating ER expression in tumor cells, in the setting of obesity-associated BC. These findings underscore a previously unknown mechanism through which interplay between cellular/extracellular elements of obesity-associated BC microenvironment influences estrogen sensitivity-a critical component in hormone-related cancer progression and resistance to therapy.

Preoperative MRI for Evaluation of Extent of Disease in IDC Compared to ILC.

OBJECTIVES: The purpose of this study was to assess the incremental value of preoperative breast MRI over mammography and US in depicting the accurate extent of disease in invasive duct carcinoma (IDC) compared to invasive lobular carcinoma (ILC). PATIENTS AND METHODS: Retrospective analysis of pre-operative mammography, US and MRI was performed in 239 patients with either IDC (n = 193) or ILC (n = 46). Images were evaluated for solitary, multifocal or multi centric disease and compared for concordance with postsurgical pathology. Discordance was documented as either overestimation or underestimation. Two tailed paired T and Fischer's exact tests were used for analysis. RESULTS: Multifocality was present on pathology in 35% and 61% of patients with IDC and ILC (P < .05) and multicentricity in 23% and 41% respectively (P = .84). In ILC, MRI demonstrated better concordance with pathology compared to mammography and US (89%, 44%, 49% for multifocality [P < .05] and 80.5%, 63%, 71% for multicentricity [P = .3]). For IDC, concordance with pathology for all modalities was similar (65%-76%). Among discordant cases, underestimation was significantly more common for mammography and US, while MRI more frequently overestimated disease extent. MRI very rarely overestimated multifocal disease in ILC (2%). CONCLUSION: MRI demonstrates an 80% to 90% concordance rate with pathology for ILC, superior to mammography and US. The addition of MRI in IDC patients may decrease underestimation of disease extent and potentially contribute to a reduction in post-operative residual disease.

Thyroid Hormones and Morphological Features of Primary Breast Cancer.

BACKGROUND/AIM: Many experimental studies have suggested the importance of thyroid hormones in breast cancer (BC) morphogenesis. The aim of this study was to evaluate the association of thyroid hormone levels in serum of patients with primary BC with morphological presentations of the disease in pathological specimens and prognosis. PATIENTS AND METHODS: We measured the serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), along with serum thymidine kinase 1 activity and examined their relation to pathological features and prognosis of 158 patients with primary BC. RESULTS: We found a significant positive association of serum FT3 level with the presence of carcinoma in situ component (CIS) (p=0.032) and its size (p=0.047), with the presence (p=0.022) and the number of multifocal/multicentric tumors (MMTs) (p=0.002), as well as with increased proliferative activity in terms of serum thymidine kinase 1 (p=0.002). Moreover, we report that each 1.0 unit rise of FT3/FT4 ratio×10 was associated with an odds ratio of 1.77 (95% confidence interval=1.17-3.30, p=0.007), 1.97 (95% confidence interval=1.17-2.67, p=0.010) and 1.56 (95% confidence interval=1.02-2.37, p=0.039) for the detection of patients with CIS, MMTs and lymphovascular invasion, respectively, after adjusting for age. We did not find statistically significant associations of serum TSH level with breast cancer`s parameters. A Cox regression survival analysis identified serum FT3 level >5.95 pmol/l as a risk factor for BC recurrence (relative risk=2.65, p=0.017), a finding that retained significance in a multivariate model (relative risk=2.52, p=0.027). CONCLUSION: The FT3/FT4 ratio is a valuable parameter predicting the presence of CIS, MMTs and lymphovascular invasion in pathological specimens. An elevated serum FT3 level is associated with the presence of CIS, MMTs, increased proliferative activity and poor prognosis.

"High-Risk Breast Cancer Screening in BRCA1/2 Carriers Leads to Early Detection and Improved Survival After a Breast Cancer Diagnosis".

BACKGROUND: Germline BRCA1/2 pathogenic variant (PV) carriers have high lifetime risk of developing breast cancer and therefore subjected to intense lifetime screening. However, solid data on the effectiveness of high-risk screening of the BRCA1/2 carrier population is limited. PATIENTS AND METHODS: Retrospectively, we analyzed 346 women diagnosed with breast tumors. Patients were divided according to the timing of BRCA1/2 PVrecognition, before (BRCA-preDx awareness, N = 62) or after (BRCA-postDx awareness group, N = 284) cancer diagnosis. RESULTS: Median follow-up times were 131.42 and 93.77 months in the BRCA-preDx awareness and BRCA-postDx awareness groups, respectively. In the BRCA-preDx awareness group, 78.7% of the patients had invasive tumors and 21.3% were diagnosed with pure ductal carcinoma in situ. In contrast, in the BRCA-postDx awareness group over 93% of women were diagnosed with invasive cancer and only 6.4% had in situ disease. The mode of tumor detection differed significantly between the groups: 71.9% in the BRCA-postDx awareness group and 26.2% in the BRCA-preDx awareness group were diagnosed after personally palpating a lump. Tumor size and nodal involvement were significantly more favorable in the BRCA-preDx awareness group. T stage was significantly lower in the BRCA-preDx awareness group: 54.84% at T1 and 20.96% at Tis. In the BRCA-postDx awareness group, only 37.54% were at T1 and 6.49% at Tis. The N stage was also significantly lower in the BRCA-preDx awareness group: 71% had no lymph node metastases, compared with 56.1% in the BRCA-postDx awareness group. Additionally, therapeutic procedures varied between the groups: BRCA-preDx awareness group patients underwent more breast conserving surgeries. Axillary lymph node dissection was done in 38% of women in the BRCA-postDx awareness group and in only 8.7% of the BRCA-preDx awareness group patients. Interestingly, improved survival was found among patients who underwent high-risk screening (hazard ratio=0.34). CONCLUSIONS: High-risk screening might facilitate downstaging of detected breast tumor among BRCA1/2 carrier population.

Elevated Free Triiodothyronine Is Associated With Increased Proliferative Activity in Triple-negative Breast Cancer.

BACKGROUND/AIM: Thyroid hormones (THs) stimulate breast cancer (BC) cell proliferation. We hypothesized that these hormones and the proliferative marker thymidine kinase 1 (TK1) represent the initial and final steps of the proliferative pathway, respectively. PATIENTS AND METHODS: We measured the serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), along with serum TK1 activity, in 144 newly diagnosed BC patients, and examined the associations between THs and proliferation in different BC receptor profiles. RESULTS: TK1 activity did not correlate with TSH (r=0.06, p=0.473) or FT4 levels (r=0.04, p=0.665), but did correlate with FT3 levels (r=0.28, p=0.001). Elevated FT3 (>6.0 pmol/l) predicted increased TK1 activity (>140 Du/l) after adjusting for age (odds ratio 4.1, p=0.014). We also found a significant association of the combined elevation of FT3 and TK1, assumed as a surrogate marker of accomplished proliferative signal, with triple-negative (TN) profile (p=0.003). The rates of combined FT3 and TK1 elevation in TN and ER-positive profiles were 20.0% and 1.8%, respectively (p=0.005). CONCLUSION: FT3 may be involved in proliferative signaling, as measured by TK1 activity, predominately in TN breast cancer.

Thyroid Hormones, Silencing Mediator for Retinoid and Thyroid Receptors and Prognosis in Primary Breast Cancer.

BACKGROUND/AIM: Silencing mediator of retinoid and thyroid receptors (SMRT) is a nuclear corepressor in thyroid and estrogen hormones pathways. The aim was to evaluate SMRT expression in relation to thyroid hormone levels and prognostic markers in breast cancer (BC). PATIENTS AND METHODS: Serum and tumor tissues were obtained from 36 patients with benign breast disease (BBD) and 79 BC patients. SMRT expression was determined by immunohistochemistry. Free-triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured in serum. RESULTS: Higher FT4, lower FT3/FT4 ratio and higher expression of SMRT were found in BC compared to BBD (for all p<0.001). In BC, increased SMRT expression was associated with lower FT3 (p=0.028), higher tumor grade (p=0.031), increased KI67 proliferation index (p=0.015), higher risk of recurrence (p=0.014) and shorter disease-free survival (p=0.006). In multivariate analysis, SMRT overexpression and below-median levels of TSH were independent prognostic factors in BC. CONCLUSION: Elevated FT4 and decreased FT3/FT4 in BC patients suggest a role for thyroid hormones in malignant transformation. SMRT tumor overexpression is associated with lower FT3 levels, tumor proliferative activity and an aggressive clinical course.

The importance of cytokines analysis in the diagnosis of vitreoretinal lymphoma.

PURPOSE: To evaluate the efficacy of the different diagnostic tests for vitreoretinal lymphoma (VRL). METHODS: A cohort of 150 patients with a presumed diagnosis of VRL. Vitrectomy samples were analysed for cytology, monoclonality [polymerase chain reaction (PCR)] and cytokine levels, and anterior chamber taps were analysed for cytokine levels. Vitreoretinal lymphoma (VRL) was diagnosed after confirming the clinical suspicion with vitreal or brain cytology. RESULTS: Vitreoretinal lymphoma (VRL) was diagnosed in 78 patients. Vitreal cytology was positive for 53/132 patients (40.2%), 36/53 had positive cytology from both the eye and the brain. Additional 25 patients had positive brain cytology. Vitreal PCR for monoclonality was positive for 32/91 patients (35.2%). Vitreal cytokine levels of interleukin (IL)-10/IL-6 were >1 for 47/110 patients (43.1%). For cytology, PCR and cytokine analysis, the respective sensitivity was 73.6%, 46.0% and 81.4%, and the accuracy of the tests was 85.6%, 60.4% and 80.9%, respectively. All three tests were available for 79 patients. In this subset, for cytology, PCR and cytokine analysis the respective sensitivity was 79.5%, 41.0% and 82.1%, respectively, and the accuracy of the tests was 89.9%, 60.8% and 81.0%, respectively. CONCLUSION: Cytokines analysis has an important role in the diagnosis of VRL. We suggest analysing cytokines levels in all cases suspected of VRL along with cytology and PCR analysis.

Heparanase Accelerates Obesity-Associated Breast Cancer Progression.

Obese women have higher risk of bearing breast tumors that are highly aggressive and resistant to therapies. Tumor-promoting effects of obesity occur locally via adipose inflammation and related alterations to the extracellular matrix (ECM) as well as systemically via circulating metabolic mediators (e.g., free fatty acids, FFA) associated with excess adiposity and implicated in toll-like receptor-mediated activation of macrophages-key cellular players in obesity-related cancer progression. Although the contribution of macrophages to proneoplastic effects of obesity is well documented, the role of ECM components and their enzymatic degradation is less appreciated. We show that heparanase, the sole mammalian endoglucuronidase that cleaves heparan sulfate in ECM, is preferentially expressed in clinical/experimental obesity-associated breast tumors. Heparanase deficiency abolished obesity-accelerated tumor progression in vivo. Heparanase orchestrated a complex molecular program that occurred concurrently in adipose and tumor tissue and sustained the cancer-promoting action of obesity. Heparanase was required for adipose tissue macrophages to produce inflammatory mediators responsible for local induction of aromatase, a rate-limiting enzyme in estrogen biosynthesis. Estrogen upregulated heparanase in hormone-responsive breast tumors. In subsequent stages, elevated levels of heparanase induced acquisition of procancerous phenotype by tumor-associated macrophages, resulting in activation of tumor-promoting signaling and acceleration of breast tumor growth under obese conditions. As techniques to screen for heparanase expression in tumors become available, these findings provide rational and a mechanistic basis for designing antiheparanase approaches to uncouple obesity and breast cancer in a rapidly growing population of obese patients. SIGNIFICANCE: This study reveals the role of heparanase in promoting obesity-associated breast cancer and provides a mechanistically informed approach to uncouple obesity and breast cancer in a rapidly growing population of obese patients.

Somatic loss of WWOX is associated with TP53 perturbation in basal-like breast cancer.

Inactivation of WW domain-containing oxidoreductase (WWOX), the gene product of the common fragile site FRA16D, is a common event in breast cancer and is associated with worse prognosis of triple-negative breast cancer (TNBC) and basal-like breast cancer (BLBC). Despite recent progress, the role of WWOX in driving breast carcinogenesis remains unknown. Here we report that ablation of Wwox in mammary tumor-susceptible mice results in increased tumorigenesis, and that the resultant tumors resemble human BLBC. Interestingly, copy number loss of Trp53 and downregulation of its transcript levels were observed in the Wwox knockout tumors. Moreover, tumors isolated from Wwox and Trp53 mutant mice were indistinguishable histologically and transcriptionally. Finally, we find that deletion of TP53 and WWOX co-occurred and is associated with poor survival of breast cancer patients. Altogether, our data uncover an essential role for WWOX as a bona fide breast cancer tumor suppressor through the maintenance of p53 stability.

RNF20 and histone H2B ubiquitylation exert opposing effects in Basal-Like versus luminal breast cancer.

Breast cancer subtypes display distinct biological traits that influence their clinical behavior and response to therapy. Recent studies have highlighted the importance of chromatin structure regulators in tumorigenesis. The RNF20-RNF40 E3 ubiquitin ligase complex monoubiquitylates histone H2B to generate H2Bub1, while the deubiquitinase (DUB) USP44 can remove this modification. We found that RNF20 and RNF40 expression and global H2Bub1 are relatively low, and USP44 expression is relatively high, in basal-like breast tumors compared with luminal tumors. Consistent with a tumor-suppressive role, silencing of RNF20 in basal-like breast cancer cells increased their proliferation and migration, and their tumorigenicity and metastatic capacity, partly through upregulation of inflammatory cytokines. In contrast, in luminal breast cancer cells, RNF20 silencing reduced proliferation, migration and tumorigenic and metastatic capacity, and compromised estrogen receptor transcriptional activity, indicating a tumor-promoting role. Notably, the effects of USP44 silencing on proliferation and migration in both cancer subtypes were opposite to those of RNF20 silencing. Hence, RNF20 and H2Bub1 have contrasting roles in distinct breast cancer subtypes, through differential regulation of key transcriptional programs underpinning the distinctive traits of each subtype.

JOURNAL CLUB: Is screening MRI indicated for women with a personal history of breast cancer? Analysis based on biopsy results.

OBJECTIVE: American College of Radiology and Society of Breast Imaging guidelines call for routine breast MRI screening only for women with the highest risk profiles for development of breast cancer, suggesting that screening of women at lower risk might result in an increased frequency of false-positive biopsy results. The purpose of this study was to test this assumption by comparing MRI-guided biopsy outcomes of lesions detected at MRI screening of women with a personal history of breast cancer with outcomes among women with genetic or familial high risk. MATERIALS AND METHODS: Outcomes of 130 MRI-guided biopsies were analyzed. One group consisted of women with hereditary (genetic or familial) risk, and the other group consisted of women with a personal history of breast cancer. Biopsies were performed with a 9-gauge vacuum-assisted device or surgically after MRI localization. RESULTS: Of 130 MRI-guided biopsies, 20 (15%) yielded malignant histologic findings, 14 (11%) yielded high-risk lesions, and 96 (74%) had benign findings. There was a slightly higher malignancy rate for the personal-risk group (19%) compared with the hereditary-risk group (13.5%). There also was a slightly higher combined rate of malignancy and high-risk lesions (34% vs 22%) with no statistically significant difference (p < 0.25, p < 0.12). Patients in the hereditary-risk group were younger (44 ± 1.2 vs 54 ± 1.7 years; p < 0.001) than those in the personal-risk group. CONCLUSION: Our preliminary data show no difference between the two risk groups with respect to probability of an MRI-guided biopsy result of malignancy, calling into question the proposed assumption. Further prospective studies of the role of MRI screening combined with MRI-guided biopsy when required for patients with previously treated localized breast cancer may be indicated.

Increased proliferative background in healthy women with BRCA1/2 haploinsufficiency is associated with high risk for breast cancer.

Previous studies indicated that BRCA haploinsufficiency was associated with activation of the EGF receptor (EGFR) signaling pathway and increased proliferative activity in mammary epithelial cells of healthy women. We hypothesized that these processes might be reflected in the expression of serologic soluble EGFR (sEGFR) and thymidine kinase 1 (TK1) activity, which signal the initial and final steps of the proliferative pathway, respectively. We found that healthy carriers of BRCA1/2 mutations (n = 80) showed a significantly higher TK1 activity than age-matched controls (P = 0.0003), and TK1 activity was similar in women with BRCA1 and BRCA2 mutations (P = 0.74). The sEGFR concentration was significantly higher in women with BRCA1 than in controls and BRCA2 mutation (P = 0.013 and 0.002, respectively). During follow-up, four of 80 BRCA1/2 mutation carriers developed breast cancer. These women showed a significantly higher TK1 activity and somewhat higher sEGFR concentrations than the other 76 BRCA1/2 carriers (P = 0.04 and 0.09, respectively). All tumors were negative for ovarian hormone receptors, but showed a high EGFR expression. This study was limited by the short-term follow-up (mean, 27 months; range, 5-45), which resulted in a small sample size. Women with BRCA1 and BRCA2 mutations that had undergone risk-reducing bilateral salpingo-oophorectomy (BSO) showed significantly lower sEGFR compared with those without surgery (P = 0.007 and 0.038, respectively). Larger, prospective studies are warranted to investigate whether TK1 and sEGFR measurements may be useful for identifying healthy BRCA1/2 carriers with high risk of developing breast cancer; moreover, sEGFR measurements may serve as effective tools for assessing risk before and after BSO.

The prognostic significance of LIAISON(R) CA15-3 assay in primary breast cancer.

AIM: To investigate the prognostic significance of cancer antigen 15-3 (CA15-3) in primary breast cancer (BC). PATIENTS AND METHODS: This prospective study included 368 women: 62 patients with benign breast disease (BBD), 159 patients with invasive BC and 88 healthy blood donors (control). The median follow-up was 76 months (range, 43-99 months). Serum CA15-3 was measured with LIAISON® CA15-3® chemilluminescence immunoassay. RESULTS: Significantly high levels of CA15-3 were found in patients with BC compared to controls (p=0.029), but not to the BBD group (p=0.16). Preoperative CA15-3 in patients with BC was significantly associated with tumor size (p=0.003), TNM stage (p=0.005), vascular invasion (p=0.018) and tumor necrosis (p<0.05). Increased CA15-3 (>30 U/ml) concentrations were more often found in patients with larger tumors (p<0.05), advanced stage (p=0.004) and node-positive disease (p=0.007). Patients with normal levels of CA15-3 had better recurrence-free survival (RFS) than those with elevated levels (p<0.001). After adjustment for T-stage, grade, tumor necrosis, estrogen receptor (ER) and progesterone receptor (PR) status, CA15-3 remained an important preoperative characteristic with independent impact on RFS (hazard ratio=4.4, 95% confidence interval=1.5-13.1, p=0.007). The independent prognostic contribution of CA15-3, considered on a continuous scale was significant among subgroups of the BC patients with ER/PR-positive (p=0.002), node-positive (p=0.028), node-negative (p=0.003), T1-stage node-negative (p=0.017), luminal-A (p=0.003), luminal-B (p=0.028) and human epidermal growth factor receptor-2 (HER2)/non-luminal disease (p=0.045). CONCLUSION: Preoperative measurement of CA15-3 allowed identifying high-risk of recurrence for patients with primary BC and might be combined with existing prognostic factors in planning adjuvant treatment.

Control of breast cancer growth and initiation by the stem cell-associated transcription factor TCF3.

Regulatory factors controlling stem cell identity and self-renewal are often active in aggressive cancers and are thought to promote their growth and progression. TCF3 (also known as TCF7L1) is a member of the TCF/LEF transcription factor family that is central in regulating epidermal and embryonic stem cell identity. We found that TCF3 is highly expressed in poorly differentiated human breast cancers, preferentially of the basal-like subtype. This suggested that TCF3 is involved in the regulation of breast cancer cell differentiation state and tumorigenicity. Silencing of TCF3 dramatically decreased the ability of breast cancer cells to initiate tumor formation, and led to decreased tumor growth rates. In culture, TCF3 promotes the sphere formation capacity of breast cancer cells and their self-renewal. We found that in contrast to ES cells, where it represses Wnt-pathway target genes, TCF3 promotes the expression of a subset of Wnt-responsive genes in breast cancer cells while repressing another distinct target subset. In the normal mouse mammary gland, Tcf3 is highly expressed in terminal end buds, structures that lead duct development. Primary mammary cells are dependent on Tcf3 for mammosphere formation, and its overexpression in the developing gland disrupts ductal growth. Our results identify TCF3 as a central regulator of tumor growth and initiation, and a novel link between stem cells and cancer.

Regulation of human protease-activated receptor 1 (hPar1) gene expression in breast cancer by estrogen.

A pivotal role is attributed to the estrogen-receptor (ER) pathway in mediating the effect of estrogen in breast cancer progression. Yet the precise mechanisms of cancer development by estrogen remain poorly understood. Advancing tumor categorization a step forward, and identifying cellular gene fingerprints to accompany histopathological assessment may provide targets for therapy as well as vehicles for evaluating the response to treatment. We report here that in breast carcinoma, estrogen may induce tumor development by eliciting protease-activated receptor-1 (PAR(1)) gene expression. Induction of PAR(1) was shown by electrophoretic mobility shift assay, luciferase reporter gene driven by the hPar(1) promoter, and chromatin-immunoprecipitation analyses. Functional estrogen regulation of hPar1 in breast cancer was demonstrated by an endothelial tube-forming network. Notably, tissue-microarray analyses from an established cohort of women diagnosed with invasive breast carcinoma exhibited a significantly shorter disease-free (P=0.006) and overall (P=0.02) survival of patients that were positive for ER and PAR(1), compared to ER-positive but PAR(1)-negative patients. We propose that estrogen transcriptionally regulates hPar(1), culminating in an aggressive gene imprint in breast cancer. While ER(+) patients are traditionally treated with hormone therapy, the presence of PAR(1) identifies a group of patients that requires additional treatment, such as anti-PAR(1) biological vehicles or chemotherapy.

Par genes: molecular probes to pathological assessment in breast cancer progression.

Taking the issue of tumor categorization a step forward and establish molecular imprints to accompany histopathological assessment is a challenging task. This is important since often patients with similar clinical and pathological tumors may respond differently to a given treatment. Protease-activated receptor-(1) (PAR(1)), a G protein-coupled receptor (GPCR), is the first member of the mammalian PAR family consisting of four genes. PAR(1) and PAR(2) play a central role in breast cancer. The release of N-terminal peptides during activation and the exposure of a cryptic internal ligand in PARs, endow these receptors with the opportunity to serve as a "mirror-image" index reflecting the level of cell surface PAR(1&2)-in body fluids. It is possible to use the levels of PAR-released peptide in patients and accordingly determine the choice of treatment. We have both identified PAR(1) C-tail as a scaffold site for the immobilization of signaling partners, and the critical minimal binding site. This binding region may be used for future therapeutic modalities in breast cancer, since abrogation of the binding inhibits PAR(1) induced breast cancer. Altogether, both PAR(1) and PAR(2) may serve as molecular probes for breast cancer diagnosis and valuable targets for therapy.

Identification and immunolocalization of the innate immune receptor CD14 in hypertrophic adenoids and tonsils.

The purpose of this study is to determine the expression of CD14 as a marker of the innate immunity in hypertrophic adenoids and tonsils. Twenty-four pediatric patients (age <12 years) with obstructive adenotonsillar hypertrophy, confirmed by sleep study were included in this study. Intensity and expression of positive CD14 infiltrating cells was assessed by immunohistochemistry in specific histologic areas. In tonsils, CD14 immunoreactivity was demonstrated in intraepithelial lymphocytes located in the basal layer of the stratified squamous mucoepithelium. CD14 expression was significantly higher in mucosal layers and inter-follicular areas of tonsils than adenoid tissues [(p < 0.001), (p = 0.021), respectively]. CD14 expression was significantly higher in the submucosal layers of adenoids than tonsil tissues (p = 0.002). Hypertrophic adenoids and tonsils from children with OSA are prominent sites of innate defense, with over expression of CD14. The enhanced expressions of CD14 cells in adenoids and tonsils may be an important factor for the development and persistence of adenoids and tonsils enlargement causing OSA in children. CD14 expression in adenoids and tonsils illustrates an important immunological sentinel function of the innate immunity of the upper airway.

Serum thymidine kinase 1 activity in breast cancer.

AIMS: Thymidine kinase 1 (TK1) is an enzyme involved in DNA synthesis and an important proliferation marker. We explored the association of preoperative serum TK1 activity with clinicopathological parameters and prognosis in terms of recurrence-free survival (RFS) in breast cancer (BC) patients. PATIENTS AND METHODS: TK1 activity in serum of 120 healthy women and 161 BC patients was measured by quantitative ELISA. RESULTS: Serum TK1 activity in BC patients was significantly higher than in healthy women (P < 0.0001). In BC patients elevated TK1 activity was significantly associated with advanced T stage (P = 0.015), higher grade (P = 0.013), presence of tumor necrosis (P = 0.006), vascular invasion (P = 0.002), and lack of estrogen receptor (ER) and progesterone receptor (PR) expression (P = 0.0004 and P = 0.003). Higher TK1 activity was found in patients with BRCA1/2 mutations compared to those without the mutation (P = 0.004). Multivariate Cox proportional hazards analyses demonstrated that TK1, adjusted for stage, grade, necrosis, ER and PR negativity was retained as an independent predictor of disease recurrence (Hazard Ratio = 3.9, 95%CI 1.3-11.6, P = 0.013). CONCLUSION: Elevated serum TK1 is an important risk factor indicating a high proliferation potential of tumors at the time of excision. In multivariate analysis TK1 activity was found to be an independent prognostic factor for RFS.