Expression of L1 Cell Adhesion Molecule, a Nephronal Principal Cell Marker, in Nephrogenic Adenoma.

Nephrogenic adenoma (NA) is a benign, reactive lesion seen predominantly in the urinary bladder and often associated with antecedent inflammation, instrumentation, or an operative history. Its histopathologic diversity can create diagnostic dilemmas and pathologists use morphologic evaluation along with available immunohistochemical (IHC) markers to navigate these challenges. IHC assays currently do not designate or specify NA's potential putative cell of origin. Leveraging single-cell RNA-sequencing technology, we nominated a principal (P) cell-collecting duct marker, L1 cell adhesion molecule (L1CAM), as a potential biomarker for NA. IHC characterization revealed L1CAM to be positive in all 35 (100%) patient samples of NA; negative expression was seen in the benign urothelium, benign prostatic glands, urothelial carcinoma (UCA) in situ, prostatic adenocarcinoma, majority of high-grade UCA, and metastatic UCA. In the study, we also used single-cell RNA sequencing to nominate a novel compendium of biomarkers specific for the proximal tubule, loop of Henle, and distal tubule (DT) (including P and intercalated cells), which can be used to perform nephronal mapping using RNA in situ hybridization and IHC technology. Employing this technique on NA we found enrichment of both the P-cell marker L1CAM and, the proximal tubule type-A and -B cell markers, PDZKI1P1 and PIGR, respectively. The cell-type markers for the intercalated cell of DTs (LINC01187 and FOXI1), and the loop of Henle (UMOD and IRX5), were found to be uniformly absent in NA. Overall, our findings show that based on cell type-specific implications of L1CAM expression, the shared expression pattern of L1CAM between DT P cells and NA. L1CAM expression will be of potential value in assisting surgical pathologists toward a diagnosis of NA in challenging patient samples.

L1 Cell Adhesion Molecule (L1CAM) Expression and Molecular Alterations Distinguish Low-Grade Oncocytic Tumor From Eosinophilic Chromophobe Renal Cell Carcinoma.

Renal low-grade oncocytic tumor (LOT) is a recently recognized renal cell neoplasm designated within the "other oncocytic tumors" category in the 2022 World Health Organization classification system. Although the clinicopathologic, immunohistochemical, and molecular features reported for LOT have been largely consistent, the data are relatively limited. The morphologic overlap between LOT and other low-grade oncocytic neoplasms, particularly eosinophilic chromophobe renal cell carcinoma (E-chRCC), remains a controversial area in renal tumor classification. To address this uncertainty, we characterized and compared large cohorts of LOT (n = 67) and E-chRCC (n = 69) and revealed notable differences between the 2 entities. Clinically, LOT predominantly affected women, whereas E-chRCC showed a male predilection. Histologically, although almost all LOTs were dominated by a small-nested pattern, E-chRCC mainly showed solid and tubular architectures. Molecular analysis revealed that 87% of LOT cases harbored mutations in the tuberous sclerosis complex (TSC)-mTOR complex 1 (mTORC1) pathway, most frequently in MTOR and RHEB genes; a subset of LOT cases had chromosomal 7 and 19q gains. In contrast, E-chRCC lacked mTORC1 mutations, and 60% of cases displayed chromosomal losses characteristic of chRCC. We also explored the cell of origin for LOT and identified L1 cell adhesion molecule (L1CAM), a collecting duct and connecting tubule principal cell marker, as a highly sensitive and specific ancillary test for differentiating LOT from E-chRCC. This distinctive L1CAM immunohistochemical labeling suggests the principal cells as the cell of origin for LOT, unlike the intercalated cell origin of E-chRCC and oncocytoma. The ultrastructural analysis of LOT showed normal-appearing mitochondria and intracytoplasmic lumina with microvilli, different from what has been described for chRCC. Our study further supports LOT as a unique entity with a benign clinical course. Based on the likely cell of origin and its clinicopathologic characteristics, we propose that changing the nomenclature of LOT to "Oncocytic Principal Cell Adenoma of the Kidney" may be a better way to define and describe this entity.

L1CAM Predicts Adverse Outcomes in Patients with Endometrial Cancer Undergoing Full Lymphadenectomy and Adjuvant Chemotherapy.

BACKGROUND: L1 cell adhesion molecule (L1CAM) has been established as an important predictor of poor survival of early-stage endometrial cancer patients. We investigated whether L1CAM remains a significant predictor of poor survival of patients with advanced-stage endometrial cancer undergoing extensive surgical staging and adjuvant chemotherapy. METHODS: We prepared tissue microarray (TMA) from surgical tissue specimens of 161 endometrial cancer patients who underwent full lymphadenectomy combined with adjuvant chemotherapy for patients at risk for recurrence, and evaluated expression of L1CAM using immunohistochemistry. The correlation between L1CAM positivity and clinicopathological factors and the prognostic significance of L1CAM expression was investigated. RESULTS: Among 161 cases who had a follow-up duration of over 3 years, 48 cases (29.8%) showed positive staining for L1CAM. L1CAM positivity was significantly correlated with non-endometrioid histology (p < 0.0001), vascular invasion (p = 0.0157), and positive cytology (p = 0.005), and was a significant predictor of poor survival among advanced-stage patients, but not early-stage patients in our cohort. L1CAM-positive patients showed a higher recurrence rate and frequency of distant failure than L1CAM-negative patients. Multivariate analysis revealed that para-aortic lymph node metastasis (PANM) and L1CAM positivity were independent predictors of poor survival. Overall survival can be stratified into three groups by the combination of PANM and L1CAM positivity. CONCLUSION: L1CAM is an independent predictor of poor survival in endometrial cancer patients undergoing full lymphadenectomy and adjuvant chemotherapy, thus indicating that L1CAM can be clinically used as a biomarker to identify those patients at increased risk of recurrence.

Exosomal L1CAM Stimulates Glioblastoma Cell Motility, Proliferation, and Invasiveness.

Immunoglobulin superfamily protein L1CAM (L1, CD171) normally facilitates neuronal migration, differentiation, and axon guidance during development. Many types of cancers, including glioblastoma (GBM), also abnormally express L1, and this has been associated with poor prognosis due to increased cell proliferation, invasiveness, or metastasis. We showed previously that the soluble L1 ectodomain, which is proteolyzed from the transmembrane form, can stimulate proliferation and motility of GBM cells in vitro by acting through integrins and fibroblast growth factor receptors (FGFRs). Minute L1-decorated exosomal vesicles also are released by GBM cells and potentially could stimulate cell motility, proliferation, and invasiveness, but this needed to be demonstrated. In the present study, we aimed to determine if minute L1-decorated extracellular vesicles (exosomes) were capable of stimulating GBM cell motility, proliferation, and invasiveness. L1-decorated exosomes were isolated from the conditioned media of the human T98G GBM cell line and were evaluated for their effects on the behavior of glioma cell lines and primary tumor cells. L1-decorated exosomes significantly increased cell velocity in the three human glioma cells tested (T98G/shL1, U-118 MG, and primary GBM cells) in a highly quantitative SuperScratch assay compared to L1-reduced exosomes from L1-attenuated T98G/shL1 cells. They also caused a marked increase in cell proliferation as determined by DNA cell cycle analysis and cell counting. In addition, L1-decorated exosomes facilitated initial GBM cell invasion when mixed with non-invasive T98G/shL1 cells in our chick embryo brain tumor model, whereas mixing with L1-reduced exosomes did not. Chemical inhibitors against focal adhesion kinase (FAK) and fibroblast growth factor receptor (FGFR) decreased L1-mediated motility and proliferation to varying degrees. These novel data show that L1-decoratred exosomes stimulate motility, proliferation and invasion to influence GBM cell behavior, which adds to the complexity of how L1 stimulates cancer cells through not only soluble ectodomain but also through exosomes.

Expression of L1CAM in curettage or high L1CAM level in preoperative blood samples predicts lymph node metastases and poor outcome in endometrial cancer patients.

BACKGROUND: Several studies have identified L1 cell adhesion molecule (L1CAM) as a strong prognostic marker in endometrial cancer. To further underline the clinical usefulness of this biomarker, we investigated L1CAM as a predictive marker for lymph node metastases and its prognostic impact in curettage specimens and preoperative plasma samples. In addition, we aimed to validate the prognostic value of L1CAM in hysterectomy specimen. METHODS: Immunohistochemical staining of L1CAM was performed for 795 hysterectomy and 1134 curettage specimen from endometrial cancer patients. The L1CAM level in preoperative blood samples from 372 patients was determined using ELISA. RESULTS: Expression of L1CAM in curettage specimen was significantly correlated to L1CAM level in corresponding hysterectomy specimen (P<0.001). Both in curettage and preoperative plasma samples L1CAM upregulation was significantly associated with features of aggressive disease and poor outcome (P<0.001). The L1CAM was an independent predictor of lymph node metastases, after correction for curettage histology, both in curettage specimen (P=0.002) and plasma samples (P=0.048). In the hysterectomy samples L1CAM was significantly associated with poor outcome (P<0.001). CONCLUSIONS: We demonstrate that preoperative evaluation of L1CAM levels, both in curettage or plasma samples, predicts lymph node metastases and adds valuable information on patient prognosis.

L1CAM expression associates with poor outcome in endometrioid, but not in clear cell ovarian carcinoma.

OBJECTIVE: Our aim was to study the expression of L1CAM in endometrioid and clear cell ovarian carcinomas and to evaluate its correlation with clinical parameters and patient prognosis. METHODS: Tissue microarray -based immunohistochemical analysis of L1CAM expression was performed in 249 endometrioid and 140 clear cell ovarian carcinomas. Concurrent endometrial carcinoma was found in 57 of these patients. RESULTS: L1CAM expression was found in 15% of endometrioid and 23% of clear cell ovarian carcinomas. L1CAM expression was strongly associated with poor disease-specific overall survival and poor disease-free survival in endometrioid (p<0.0001, p=0.0005), but not in clear cell ovarian carcinomas. Significant association of L1CAM expression with poor overall survival was observed in grade 1-2 carcinomas (p<0.0001), but not in grade 3 tumors. In endometrioid ovarian carcinomas, L1CAM expression was associated with aggressive tumor characteristics, such as higher grade and stage, and incomplete response to primary therapy. However, L1CAM expression was not an independent prognostic factor for overall or disease-free survival. Of the 57 patients with concurrent endometrial carcinoma L1CAM positivity was found in 4 cases both in the ovarian and endometrial tumors, and in 3 cases only in the endometrial tumor. All these seven patients with L1CAM positive tumors had poor outcome. CONCLUSIONS: L1CAM expression could serve as a biomarker for predicting clinical outcome and response to therapy in patients with endometrioid ovarian carcinoma, but not in clear cell carcinomas. L1CAM positivity also predicts poor outcome in patients with concurrent endometrioid ovarian and endometrial carcinomas.

L1CAM and HER2 Expression in Early Endometrioid Uterine Cancer.

Recently L1CAM was shown to be a promising biomarker for early-stage endometrial carcinoma (EC). As L1CAM expression was found to be related to serous ECs and areas of serous differentiation in endometrioid carcinomas, there is evidence that L1CAM-positive cancers more likely resemble type II carcinomas. Furthermore, expression of growth factor receptor HER2 has been found to be closely associated with serous ECs. We conducted a retrospective study on 142 patients in FIGO stages I and II with endometrioid EC and analyzed L1CAM and HER2 expression by double-staining immunohistochemistry. The association between these 2 transmembrane molecules and their impact on patient outcome was analyzed. Both L1CAM and HER2 showed a significant association with recurrent disease (P<0.001 and P=0.007, respectively). We found 39 (27%) L1CAM-positive cases and 17 (12%) HER2-positive cases. About 6.3% of cases were positive for both biomarkers. Survival of L1CAM-positive patients showed a significant difference between HER2-positive and HER2-negative patients (P=0.019) regarding disease-free survival. The most unfavorable disease-free survival and overall survival was found for patients with L1CAM and HER2 double-positive tumors (P<0.001). Double immunostaining revealed a mutually exclusive staining pattern for L1CAM and HER2 expression on the level of tumor cells. In early endometrioid uterine carcinoma, an additional expression of HER2 to L1CAM seems to further worsen disease-free survival and overall survival. In terms of "personalized medicine," detection of these molecules in endometrioid ECs may open new avenues for targeted therapies with the newly available anti-HER2 drugs and/or with the upcoming humanized anti-L1CAM antibodies.

Preoperative Risk Stratification of Endometrial Carcinoma: L1CAM as a Biomarker.

OBJECTIVE: Preoperative or intraoperative risk assessment models are used to stratify patients with endometrial carcinoma to lymphadenectomy. Our aim was to determine whether preoperative analysis of L1 cell adhesion molecule (L1CAM) can improve risk assessment. METHODS: Immunohistochemical L1CAM staining was performed on endometrial biopsies of 241 patients and paired hysterectomy samples of 75 patients. Risk assessment models based on preoperative histologic type and grade, myometrial invasion, and/or tumor diameter and alternative models incorporating preoperative L1CAM were compared with regard to their capability of predicting lymph nodal or distant metastasis. Soluble L1 levels were measured by enzyme-linked immunosorbent assay in serum samples of 40 patients with endometrial carcinoma. RESULTS: The concordance rate between L1CAM staining results of preoperative and hysterectomy samples was moderate (κ = 0.586, P < 0.0001). Preoperative L1CAM expression was associated with nonendometrioid histology, lymph node involvement, advanced stage, and positive peritoneal cytology. Receiver operating characteristic curve analyses showed that L1CAM did not significantly improve risk stratification algorithms based on traditional risk factors. Intraoperative tumor diameter was an effective surrogate for myometrial invasion. There was no statistical difference between L1 serum levels of patients with an L1CAM-positive or L1CAM-negative endometrial carcinoma (P = 0.786). CONCLUSIONS: L1 cell adhesion molecule expression in endometrial biopsy correlates with high-risk features of endometrial carcinoma but does not significantly improve risk stratification algorithms based on traditional factors. Soluble L1 detected in the serum of patients with endometrial carcinoma does not correlate with tumoral L1CAM expression.

L1CAM expression in endometrial carcinomas: an ENITEC collaboration study.

BACKGROUND: Identification of aggressive endometrioid endometrial carcinomas (EECs) and non-endometrioid carcinomas (NEECs) is essential to improve outcome. L1 cell adhesion molecule (L1CAM) expression is a strong prognostic marker in stage I EECs, but less is known about L1CAM expression in advanced-stage EECs and NEECs. This study analyses L1CAM expression in a clinically representative cohort of endometrial carcinomas. METHODS: The expression of L1CAM was immunohistochemically determined in 1199 endometrial carcinomas, treated at one of the European Network for Individualized Treatment of Endometrial Cancer (ENITEC) centres. Staining was considered positive when >10% of the tumour cells expressed L1CAM. The association between L1CAM expression and several clincopathological characteristics and disease outcome was calculated. RESULTS: In all, L1CAM was expressed in 10% of the 935 stage I EECs, 18% of the 160 advanced stage EECs, and 75% of the 104 NEECs. The expression of L1CAM was associated with advanced stage, nodal involvement, high tumour grade, non-endometrioid histology, lymphovascular space invasion, and distant recurrences in all cases, and with reduced survival in the EECs, but not in the NEECs. CONCLUSIONS: The expression of L1CAM is a strong predictor of poor outcome in EECs, but not NEECs. It is strongly associated with non-endometrioid histology and distant spread, and could improve the postoperative selection of high-risk endometrial carcinomas. The value of L1CAM expression in the preoperative selection of high-risk endometrial carcinomas should be studied.

Prognostic significance of L1CAM expression and its association with mutant p53 expression in high-risk endometrial cancer.

Studies in early-stage, predominantly low- and intermediate-risk endometrial cancer have demonstrated that L1 cell adhesion molecule (L1CAM) overexpression identifies patients at increased risk of recurrence, yet its prognostic significance in high-risk endometrial cancer is unclear. To evaluate this, its frequency, and the relationship of L1CAM with the established endometrial cancer biomarker p53, we analyzed the expression of both markers by immunohistochemistry in a pilot series of 116 endometrial cancers (86 endometrioid, 30 non-endometrioid subtype) with high-risk features (such as high tumor grade and deep myometrial invasion) and correlated results with clinical outcome. We used The Cancer Genome Atlas (TCGA) endometrial cancer series to validate our findings. Using the previously reported cutoff of 10% positive staining, 51/116 (44%) tumors were classified as L1CAM-positive, with no significant association between L1CAM positivity and the rate of distant metastasis (P=0.195). However, increasing the threshold for L1CAM positivity to 50% resulted in a reduction of the frequency of L1CAM-positive tumors to 24% (28/116), and a significant association with the rate of distant metastasis (P=0.018). L1CAM expression was strongly associated with mutant p53 in the high-risk and TCGA series (P<0.001), although a substantial fraction (36% of endometrioid, 10% of non-endometrioid morphology) of p53-mutant endometrial cancers displayed <10% L1CAM positivity. Moreover, 30% of p53-wild-type non-endometrioid endometrial cancers demonstrated diffuse L1CAM staining, suggesting p53-independent mechanisms of L1CAM overexpression. In conclusion, the previously proposed threshold for L1CAM positivity of >10% does not predict prognosis in high-risk endometrial cancer, whereas an alternative threshold (>50%) does. L1CAM expression is strongly, but not universally, associated with mutant p53, and may be strong enough for clinical implementation as prognostic marker in combination with p53. The high frequency of L1CAM expression in high-risk endometrial cancers suggests that it may also be a promising therapeutic target in this tumor subset.

L1CAM as a prognostic marker in stage I endometrial cancer: a validation study.

BACKGROUND: L1 cell adhesion molecule (L1CAM) overexpression has been reported to be strongly associated with poor prognosis in early stage endometrial cancer (EC). We aimed at the validation of L1CAM as a marker of poor prognosis in an independent study population. METHODS: Patients with endometrioid EC FIGO stage I, were treated at Oslo University Hospital between 2005 and 2012. L1CAM expression was detected by immunohistochemistry with >10 % L1CAM staining defined as positive. Risks of relapse and death were estimated as hazard ratios (HRs) with 95 % confidence intervals (95 % CI). RESULTS: Of 450 patients, 388 (86 %) were evaluable for L1CAM expression and 35 (9 %) were L1CAM positive. After follow-up for a median time of 4.8 years (0.1-8.8), 33 (8 %) patients had recurred. 6/35 (17 %) L1CAM positive patients relapsed compared to 27/353 (8 %) L1CAM-negative patients. There were 7 (20 %) deaths in the L1CAM positive group, and 34 (10 %) in the negative group. In multivariate analysis, controlled for age and FIGO stage, L1CAM positivity was not significantly associated with the risk of relapse (HR 2.08, 95 % CI: 0.85-5.10, p = 0.11) or death of all-cause (HR 1.81, 95 % CI: 0.79-4.11, p = 0.16). In patients who were not treated with chemotherapy, L1CAM was significantly associated with risk of relapse (HR 2.9; 95 % CI: 1.08-7.56; p = 0.04). CONCLUSION: Our report confirms that L1CAM is associated with a more aggressive tumortype and more distant relapses. The overall recurrence rate in this population was low as were the absolute differences between L1CAM positive and negative patients. In this independent study sample, L1CAM failed to be a clinically relevant marker of poor prognosis in stage I endometrioid endometrial carcinoma.

Asparaginase-like protein 1 as a prognostic tissue biomarker in clinicopathologically and molecularly characterized endometrial cancer.

OBJECTIVE: Prognostic stratification of endometrial cancer involves the assessment of stage, uterine risk factors, and molecular classification. This process can be further refined through annotation of prognostic biomarkers, notably L1 cell adhesion molecule (L1CAM) and hormonal receptors. Loss of asparaginase-like protein 1 (ASRGL1) has been shown to correlate with poor outcome in endometrial cancer. Our objective was to assess prognostication of endometrial cancer by ASRGL1 in conjunction with other available methodologies. STUDY DESIGN: This was a retrospective study of patients who underwent primary treatment at a single tertiary center. Tumors were molecularly classified by the Proactive Molecular Risk Classifier for Endometrial Cancer. Expression of ASRGL1, L1CAM, estrogen receptor, and progesterone receptor was determined by immunohistochemistry. ASRGL1 expression intensity was scored into four classes. RESULTS: In a cohort of 775 patients, monitored for a median time of 81 months, ASRGL1 expression intensity was related to improved disease-specific survival in a dose-dependent manner (P < 0.001). Low expression levels were associated with stage II-IV disease and presence of uterine factors, i.e. high grade, lymphovascular space invasion, and deep myometrial invasion (P < 0.001 for all). Among the molecular subgroups, low expression was most prevalent in p53 abnormal carcinomas (P < 0.001). Low ASRGL1 was associated with positive L1CAM expression and negative estrogen and progesterone receptor expression (P < 0.001 for all). After adjustment for stage and uterine factors, strong ASRGL1 staining intensity was associated with a lower risk for cancer-related deaths (hazard ratio 0.56, 95 % confidence interval 0.32-0.97; P = 0.038). ASRGL1 was not associated with the outcome when adjusted for stage, molecular subgroups, L1CAM, and hormonal receptors. When analyzed separately within the different molecular subgroups, ASRGL1 showed an association with disease-specific survival specifically in "no specific molecular profile" subtype carcinomas (P < 0.001). However, this association became nonsignificant upon controlling for confounders. CONCLUSIONS: Low ASRGL1 expression intensity correlates with poor survival in endometrial cancer. ASRGL1 contributes to more accurate prognostication when controlled for stage and uterine factors. However, when adjusted for stage and other biomarkers, including molecular subgroups, ASRGL1 does not improve prognostic stratification.

The immunohistochemical expression of CD24 and CD171 adhesion molecules in borderline ovarian tumors.

CD24 and CD171 are cell adhesion proteins, which have been shown to be overexpressed in several carcinomas and to be associated with a poor clinical outcome. Our aim was to determine the expression of these two adhesion molecules in ovarian borderline neoplasms. We investigated 50 ovarian borderline tumors (serous, mucinous and endometrioid) as well as 29 benign cystadenomas and 25 carcinomas, which were used as controls. Paraffin sections were stained immunohistochemically for CD24 and CD171, and their expression was recorded in a semi-quantitative manner. In normal epithelium and benign ovarian cystadenomas both the CD24 and CD171 expression was negative to low, while their expression was significantly increased in borderline and malignant ovarian tumors. High-grade carcinomas, and carcinomas with metastases to the omentum presented considerably higher CD24 expression than low-grade carcinomas, and carcinomas without metastases. In addition, a few borderline and many malignant tumors presented cytoplasmic CD24 immunoreactivity, whereas all benign and most borderline tumors showed apical localization of this molecule. In conclusion, borderline tumors and carcinomas of the ovary present increased expression of CD24 and CD171 in relation to their benign counterparts, as is the case in malignant tumors of other organs. Change of staining pattern of CD24 (apical to cytoplasmic) apparently relates to a more aggressive phenotype.

L1CAM Is Not a Predictive Factor in Early-stage Squamous-cell Cervical Cancer.

AIM: Our study aimed to assess expression of L1 cell adhesion molecule (L1CAM) in early-stage cervical squamous-cell cancer as a prognostic factor. PATIENTS AND METHODS: This retrospective, single-institution study included 154 patients who underwent radical hysterectomy for early-stage squamous cell cervical cancer between 2007 and 2017. Tumor samples from 154 patients were available for L1CAM analysis by immunohistochemistry. Among all patients, radical abdominal hysterectomy was performed in 144 cases. RESULTS: L1CAM expression was positive in 24 tumors (15.6%) of the whole group. In relation to the grade of differentiation and the presence of lymphovascular invasion, L1CAM expression did not show an association (p=0.154 and p=0.306, respectively). The disease-free interval and overall survival also did not significantly differ between L1CAM-positive and L1CAM-negative cases (p=0.427 and p=0.240, respectively). For histopathological characteristics, L1CAM-positive cases had a significantly higher median tumor size (p=0.015). Even in the selected group of 115 cases without nodal infiltration, L1CAM status had no effect on the relapse rate during follow-up. CONCLUSION: Our study did not confirm the results of previous studies showing L1CAM expression to be a negative prognostic factor in cervical cancer. In our study, increased L1CAM expression in early-stage squamous-cell cervical cancer was not associated with adverse prognosis regarding disease recurrence, disease-free survival, nor overall survival. L1CAM expression was correlated only with the size of the tumor.

Genotype-phenotype correlations in L1 syndrome: a guide for genetic counselling and mutation analysis.

OBJECTIVES: To develop a comprehensive mutation analysis system with a high rate of detection, to develop a tool to predict the chance of detecting a mutation in the L1CAM gene, and to look for genotype-phenotype correlations in the X-linked recessive disorder, L1 syndrome. METHODS: DNA from 367 referred patients was analysed for mutations in the coding sequences of the gene. A subgroup of 100 patients was also investigated for mutations in regulatory sequences and for large duplications. Clinical data for 106 patients were collected and used for statistical analysis. RESULTS: 68 different mutations were detected in 73 patients. In patients with three or more clinical characteristics of L1 syndrome, the mutation detection rate was 66% compared with 16% in patients with fewer characteristics. The detection rate was 51% in families with more than one affected relative, and 18% in families with one affected male. A combination of these two factors resulted in an 85% detection rate (OR 10.4, 95% CI 3.6 to 30.1). The type of mutation affects the severity of L1 syndrome. Children with a truncating mutation were more likely to die before the age of 3 than those with a missense mutation (52% vs 8%; p=0.02). CONCLUSIONS: We developed a comprehensive mutation detection system with a detection rate of almost 20% in unselected patients and up to 85% in a selected group. Using the patients' clinical characteristics and family history, clinicians can accurately predict the chance of finding a mutation. A genotype-phenotype correlation was confirmed. The occurrence of (maternal) germline mosaicism was proven.

Plasmodium berghei ANKA: erythropoietin activates neural stem cells in an experimental cerebral malaria model.

Cerebral malaria (CM) causes substantial mortality and neurological sequelae in survivors, and no neuroprotective regimens are currently available for this condition. Erythropoietin (EPO) reduces neuropathology and improves survival in murine CM. Using the Plasmodium berghei model of CM, we investigated if EPO's neuroprotective effects include activation of endogenous neural stem cells (NSC). By using immunohistochemical markers of different NSC maturation stages, we show that EPO increased the number of nestin(+) cells in the dentate gyrus and in the sub-ventricular zone of the lateral ventricles, relative to control-treatment. 75% of the EPO-treated CM mice displayed migration as nestin(+) NSC. The NSC showed differentiation towards a neural cell lineage as shown by PSA-NCAM binding and NSC maturation and lineage commitment was significantly affected by exogenous EPO and by CM in the sub ventricular zone. These results indicate a rapid, EPO-dependent activation of NSC during CM pathology.

Improving preoperative diagnosis in endometrial cancer using systematic morphological assessment and a small immunohistochemical panel.

Preoperative histopathological classification determines the primary surgical approach in endometrial carcinoma (EC) patients but has only moderate agreement between preoperative and postoperative diagnosis. The aim of the PIpelle Prospective ENDOmetrial carcinoma (PIPENDO) study is to determine whether histopathological assessment and a small panel of diagnostic biomarkers decreases discrepancies between preoperative and postoperative diagnosis in EC. Preoperative endometrial tissue of 378 included patients with EC was stained with 15 different antibodies. Clinically relevant discrepancies in grade or histological subtype between original preoperative and reviewed postoperative diagnosis were observed in 75 (20%) patients. Highest clinically relevant discrepancy was found in grade 2 ECs (20%), compared to 5% and 14% in respectively grade 1 and 3 endometrioid endometrial carcinomas (EECs). A practical two-biomarker panel with PR and p53 improved diagnostic accuracy (AUC = 0.92; 95%CI = 0.88-0.95) compared to solely morphological evaluation (AUC = 0.86). In preoperative high-grade EC, the diagnostic accuracy of histological subtype was improved by a three-immunohistochemical biomarker panel (PR, IMP3, and L1CAM) (AUC = 0.93; 95%CI = 0.88-0.98) compared to solely morphological evaluation (AUC = 0.81). In conclusion to improve correct preoperative diagnosis in EC, we recommend use of a panel of at least two easily accessible immunohistochemical biomarkers (PR and p53), only in grade 2 ECs. Overall, this will reduce clinically relevant discrepancies in tumor grade and subtype with postoperative diagnosis with 6% (from 20% to 14%). Addition of PR, IMP3, and L1CAM for histological subtyping in high-grade EECs resulted in a further decrease in discrepancies with 8% (from 20% to 12%).

Immunohistochemical analysis of L1 cell adhesion molecule and high endothelial venules in breast cancer brain metastasis.

BACKGROUND: The vasculature is a crucial factor in tumor development. Vascular co-option achieved by the L1 cell adhesion molecule (L1CAM) and lymphocyte recruitment inside tumors by high endothelial venules (HEVs) are important prognostic factors in primary breast cancer. Their status in breast cancer brain metastasis is unknown. AIM OF THE STUDY: To explore the status of L1CAMs and HEVs in this tumor compartment. MATERIAL AND METHODS: Thirty resected breast cancer brain metastases were immunohistochemically studied for L1CAM and MECA-79, an HEV marker. Clinicopathological factors were recorded. RESULTS: Age at brain metastasis diagnosis ranged from 37 to 80 years (median 55). The time to brain metastasis development after primary tumor diagnosis ranged from 12 to 187 months (median 57). Median overall survival after brain metastasis diagnosis was 29 months. None of the tumors expressed the factors studied. CONCLUSION: L1CAM and high endothelial venules are not found in breast cancer brain metastasis.

Heterogeneity in progenitor cell subtypes in the ventricular zone of the zebrafish adult telencephalon.

The zebrafish has become a new model for adult neurogenesis, owing to its abundant neurogenic areas in most brain subdivisions. Radial glia-like cells, actively proliferating cells, and label-retaining progenitors have been described in these areas. In the telencephalon, this complexity is enhanced by an organization of the ventricular zone (VZ) in fast and slow-dividing domains, suggesting the existence of heterogeneous progenitor types. In this work, we studied the expression of various transgenic or immunocytochemical markers for glial cells (gfap:gfp, cyp19a1b:gfp, BLBP, and S100beta), progenitors (nestin:gfp and Sox2), and neuroblasts (PSA-NCAM) in cycling progenitors of the adult zebrafish telencephalon (identified by expression of proliferating cell nuclear antigen (PCNA), MCM5, or bromodeoxyuridine incorporation). We demonstrate the existence of distinct populations of dividing cells at the adult telencephalic VZ. Progenitors of the overall slow-cycling domains express high levels of Sox2 and nestin:gfp as well as all glial markers tested. In contrast, domains with an overall fast division rate are characterized by low or missing expression of glial markers. PCNA-positive cells in fast domains further display a morphology distinct from radial glia and co-express PSA-NCAM, suggesting that they are early neuronal precursors. In addition, the VZ contains cycling progenitors that express neither glial markers nor nestin:gfp, but are positive for Sox2 and PSA-NCAM, identifying them as committed neuroblasts. On the basis of the marker gene expression and distinct cell morphologies, we propose a classification for the dividing cell states at the zebrafish adult telencephalic VZ.