Tight junction protein claudin-1 is differentially expressed in craniopharyngioma subtypes and indicates invasive tumor growth

Unraveling the complexity of the senescence-associated secretory phenotype in adamantinomatous craniopharyngioma using multimodal machine learning analysis

BACKGROUND

Cellular senescence can have positive and negative effects on the body, including aiding in damage repair and facilitating tumor growth. Adamantinomatous craniopharyngioma (ACP), the most common pediatric sellar/suprasellar brain tumor, poses significant treatment challenges. Recent studies suggest that senescent cells in ACP tumors may contribute to tumor growth and invasion by releasing a senesecence-associated secretory phenotype. However, a detailed analysis of these characteristics has yet to be completed.

METHODS

We analyzed primary tissue samples from ACP patients using single-cell, single-nuclei, and spatial RNA sequencing. We performed various analyses, including gene expression clustering, inferred senescence cells from gene expression, and conducted cytokine signaling inference. We utilized LASSO to select essential gene expression pathways associated with senescence. Finally, we validated our findings through immunostaining.

RESULTS

We observed significant diversity in gene expression and tissue structure. Key factors such as NFKB, RELA, and SP1 are essential in regulating gene expression, while senescence markers are present throughout the tissue. SPP1 is the most significant cytokine signaling network among ACP cells, while the Wnt signaling pathway predominantly occurs between epithelial and glial cells. Our research has identified links between senescence-associated features and pathways, such as PI3K/Akt/mTOR, MYC, FZD, and Hedgehog, with increased P53 expression associated with senescence in these cells.

CONCLUSIONS

A complex interplay between cellular senescence, cytokine signaling, and gene expression pathways underlies ACP development. Further research is crucial to understand how these elements interact to create novel therapeutic approaches for patients with ACP.

Risk-benefit analysis of surgical treatment strategies for cystic craniopharyngioma in children and adolescents

Objective

Treatment strategies for craniopharyngiomas are still under debate particularly for the young population. We here present tumor control and functional outcome data after surgical treatment focusing on stereotactic and microsurgical procedures for cystic craniopharyngiomas in children and adolescents.

Methods

From our prospective institutional database, we identified all consecutive patients less than 18 years of age who were surgically treated for newly-diagnosed cystic craniopharyngioma between, 2000 and, 2022. Treatment decisions in favor of stereotactic treatment (STX) or microsurgery were made interdisciplinary. STX included aspiration and/or implantation of an internal shunt catheter for permanent cyst drainage. Microsurgery aimed for safe maximal tumor resections. Study endpoints were time to tumor recurrence (TTR) and functional outcome including ophthalmological/perimetric, endocrinological, and body-mass index (BMI) data.

Results

29 patients (median age 9.9 yrs, range 4-18 years) were analyzed. According to our interdisciplinary tumor board recommendation, 9 patients underwent stereotactic treatment, 10 patients microsurgical resection, and 10 patients the combination of both. Significant volume reduction was particularly achieved in the stereotactic (p=0.0019) and combined subgroups (p<0.001). Improvement of preoperative visual deficits was always achieved independent of the applied treatment modality. Microsurgery and the combinational treatment were associated with higher rates of postoperative endocrinological dysfunction (p<0.0001) including hypothalamic obesity (median BMI increase from 17.9kg/m2 to 24.1kg/m2, p=0.019). Median follow-up for all patients was 93.9 months (range 3.2-321.5 months). Recurrent tumors were seen in 48.3% and particularly concerned patients after initial combination of surgery and STX (p=0.004). In here, TTR was 35.1 ± 46.9 months. Additional radiation therapy was found indicated in 4 patients to achieve long-lasting tumor control.

Conclusion

In children and adolescents suffering from predominantly cystic craniopharyngiomas, stereotactic and microsurgical procedures can improve clinical symptoms at low procedural risk. Microsurgery, however, bears a higher risk of postoperative endocrine dysfunction. A risk-adapted surgical treatment concept may have to be applied repeatedly in order to achieve long-term tumor control even without additional irradiation.

The molecular pathogenesis of craniopharyngiomas

Research from the last 20 years has provided important insights into the molecular pathogenesis of craniopharyngiomas (CPs). Besides the well-known clinical and histological differences between the subtypes of CPs, adamantinomatous (ACP) and papillary (PCP) craniopharyngiomas, other molecular differences have been identified, further elucidating pathways related to the origin and development of such tumors. The present minireview assesses current knowledge on embryogenesis and the genetic, epigenetic, transcriptomic, and signaling pathways involved in the ACP and PCP subtypes, revealing the similarities and differences in their profiles. ACP and PCP subtypes can be identified by the presence of mutations in CTNNB1 and BRAF genes, with prevalence around 60% and 90%, respectively. Therefore, β-catenin accumulates in the nucleus-cytoplasm of cell clusters in ACPs and, in PCPs, cell immunostaining with specific antibody against the V600E-mutated protein can be seen. Distinct patterns of DNA methylation further differentiate ACPs and PCPs. In addition, research on genetic and epigenetic changes and tumor microenvironment specificities have further clarified the development and progression of the disease. No relevant transcriptional differences in ACPs have emerged between children and adults. In conclusion, ACPs and PCPs present diverse genetic signatures and each subtype is associated with specific signaling pathways. A better understanding of the pathways related to the growth of such tumors is paramount for the development of novel targeted therapeutic agents.

The Challenging Management of Craniopharyngiomas in Adults: Time for a Reappraisal?

Simple Summary

Craniopharyngiomas (CPs) currently represent one of the most challenging diseases to deal with in the group of skull base tumors. Due to their location near, within, or surrounding the pituitary gland and stalk, CPs can be revealed by pituitary tumor syndrome and/or symptoms of hormonal deficiencies. Furthermore, surgery, which represents the first-line therapy, almost always results in hypopituitarism, diabetes insipidus and, in the case of hypothalamic involvement by the tumor, the occurrence of hypothalamic syndrome. The latter is characterized by intractable weight gain associated with severe morbid obesity, memory impairment, attention deficit, reduced impulse control and, eventually, increased risk of cardiovascular and metabolic disorders. Recent progress made in the understanding of the molecular pathways involved in CPs tumorigenesis paves the way for promising alternative therapeutic approaches and diagnostic procedures. Taken together, they lay the groundwork for new paradigms in the management of CPs in adults.

Abstract

Craniopharyngiomas (CPs) are rare tumors of the skull base, developing near the pituitary gland and hypothalamus and responsible for severe hormonal deficiencies and an overall increase in mortality rate. While surgery and radiotherapy represent the recommended first-line therapies for CPs, a new paradigm for treatment is currently emerging, as a consequence of accumulated knowledge concerning the molecular mechanisms involved in tumor growth, paving the way for anticipated use of targeted therapies. Significant clinical and basic research conducted in the field of CPs will undoubtedly constitute a real step forward for a better understanding of the behavior of these tumors and prevent associated complications. In this review, our aim is to summarize the multiple steps in the management of CPs in adults and emphasize the most recent studies that will contribute to advancing the diagnostic and therapeutic algorithms.

A multi-task two-path deep learning system for predicting the invasiveness of craniopharyngioma

BACKGROUND AND OBJECTIVE

Craniopharyngioma is a kind of benign brain tumor in histography. However, it might be clinically aggressive and have severe manifestations, such as increased intracranial pressure, hypothalamic-pituitary dysfunction, and visual impairment. It is considered challenging for radiologists to predict the invasiveness of craniopharyngioma through MRI images. Therefore, developing a non-invasive method that can predict the invasiveness and boundary of CP as a reference before surgery is of clinical value for making more appropriate and individualized treatment decisions and reducing the occurrence of inappropriate surgical plan choices.

METHODS

The MT-Brain system has consisted of two pathways, a sub-path based on 2D CNN for capturing the features from each slice of MRI images, and a 3D sub-network for capturing additional context information between slices. By introducing the two-path architecture, our system can make full use of the fusion of the above 2D and 3D features for classification. Furthermore, position encoding and mask-guided attention also have been introduced to improve the segmentation and diagnosis performance. To verify the performance of the MT-Brain system, we have enrolled 1032 patients with craniopharyngioma (302 invasion and 730 non-invasion patients), segmented the tumors on postcontrast coronal T1WI and randomized them into a training dataset and a testing dataset at a ratio of 8:2.

RESULTS

The MT-Brain system achieved a remarkable performance in diagnosing the invasiveness of craniopharyngioma with the AUC of 83.84%, the accuracy of 77.94%, the sensitivity of 70.97%, and the specificity of 80.99%. In the lesion segmentation task, the predicted boundaries of lesions were similar to those labeled by radiologists with the dice of 66.36%. In addition, some explorations also have been made on the interpretability of deep learning models, illustrating the reliability of the model.

CONCLUSIONS

To the best of our knowledge, this study is the first to develop an integrated deep learning model to predict the invasiveness of craniopharyngioma preoperatively and locate the lesion boundary synchronously on MRI. The excellent performances indicate that the MT-Brain system has great potential in real-world clinical applications.

CLDN1 regulates trophoblast apoptosis and proliferation in preeclampsia

Preeclampsia is a gestational hypertensive disease; however, preeclampsia remains poorly understood. Bioinformatics analysis was applied to find novel genes involved in the pathogenesis of preeclampsia and identified CLDN1 as one of the most differentially expressed genes when comparing patients with preeclampsia and healthy controls. The results of the qRT-PCR, Western blotting and immunohistochemistry experiments demonstrated that CLDN1 was significantly downregulated in the chorionic villi in samples from patients with preeclampsia. Furthermore, knockdown of CLDN1 in HTR-8/SVneo cells resulted in the inhibition of proliferation and induction of apoptosis, and overexpression of CLDN1 reversed these effects. In addition, RNA-seq assays demonstrated that the gene BIRC3 is potentially downstream of CLDN1 and is involved in the regulation of apoptosis. Knockdown of CLDN1 confirmed that the expression level of BIRC3 was obviously decreased and was associated with a significant increase in cleaved PARP. Interestingly, the apoptotic effect in CLDN1 knockdown cells was rescued after BIRC3 overexpression. Overall, these results indicate that a decrease in CLDN1 inhibits BIRC3 expression and increases cleaved PARP levels thus participating in the pathogenesis of preeclampsia.

Epigenetic Regulation of Claudin-1 in the Development of Ovarian Cancer Recurrence and Drug Resistance

Over 21,000 women are diagnosed with ovarian cancer (OC) in the United States each year and over half that number succumb to this disease annually, often due to recurrent disease. A deeper understanding of the molecular events associated with recurrent disease is needed to identify potential targets. Using genome-scale DNA methylation and gene expression data for 16 matched primary-recurrent advanced stage serous epithelial OCs, we discovered that Claudin-1 (CLDN1), a tight junction protein, shows a stronger correlation between expression and methylation in recurrent versus primary OC at multiple CpG sites (R= –0.47 to −0.64 versus R= -0.32 to −0.57, respectively). An independent dataset showed that this correlation is stronger in tumors from short-term (<3y) survivors than in tumors from long-term (>7y) survivors (R= −0.41 to −0.46 versus R= 0.06 to −0.19, respectively). The presence of this inverse correlation in short-term survivors and recurrent tumors suggests an important role for this relationship and potential predictive value for disease prognosis. CLDN1 expression increased following pharmacologic inhibition of DNA methyltransferase activity (p< 0.001), thus validating the role of methylation in CLDN1 gene inhibition. CLDN1 knockdown enhanced chemosensitivity and suppressed cell proliferation, migration, and wound healing (p< 0.05). Stable CLDN1 knockdown in vivo resulted in reduced xenograft tumor growth but did not reach significance. Our results indicate that the relationship between CLDN1 methylation and expression plays an important role in OC aggressiveness and recurrence.

Non-Invasive Radiomics Approach Predict Invasiveness of Adamantinomatous Craniopharyngioma Before Surgery

Purpose

Craniopharyngiomas (CPs) are benign tumors, complete tumor resection is considered to be the optimal treatment. However, although histologically benign, the local invasiveness of CPs commonly contributes to incomplete resection and a poor prognosis. At present, some advocate less aggressive surgery combined with radiotherapy as a more reasonable and effective means of protecting hypothalamus function and preventing recurrence in patients with tight tumor adhesion to the hypothalamus. Hence, if a method can be developed to predict the invasiveness of CP preoperatively, it will help in the development of a more personalized surgical strategy. The aim of the study was to report a radiomics-clinical nomogram for the individualized preoperative prediction of the invasiveness of adamantinomatous CP (ACPs) before surgery.

Methods

In total, 1,874 radiomics features were extracted from whole tumors on contrast-enhanced T1-weighted images. A support vector machine trained a predictive model that was validated using receiver operating characteristic (ROC) analysis on an independent test set. Moreover, a nomogram was constructed incorporating clinical characteristics and the radiomics signature for individual prediction.

Results

Eleven features associated with the invasiveness of ACPs were selected by using the least absolute shrinkage and selection operator (LASSO) method. These features yielded area under the curve (AUC) values of 79.09 and 73.5% for the training and test sets, respectively. The nomogram incorporating peritumoral edema and the radiomics signature yielded good calibration in the training and test sets with the AUCs of 84.79 and 76.48%, respectively.

Conclusion

The developed model yields good performance, indicating that the invasiveness of APCs can be predicted using noninvasive radiological data. This reliable, noninvasive tool can help clinical decision making and improve patient prognosis.

Craniopharyngiomas in children - experience of consecutive 152 operated cases

CONTEXT

Craniopharyngiomas (CPH) are benign tumors, rarely encountered in children, representing 5-6% of all intracranial tumors.

OBJECTIVE

This study aimed to analyze the surgical management and quality of life in a series of CPH pediatric cases.

DESIGN

This was a multicenter study performed over a 25-year period (1994 - 2019) in Bucharest.

SUBJECTS AND METHODS

152 children (0-17 years old) were treated for CPH. Preoperative manifestations were intracranial hypertension, endocrine dysfunction, visual impairment, ataxia, intellectual performance decrease.

RESULTS

Considering all surgical approaches used, we advocate for pterional approach to best fit in CPH. We achieved gross-total removal (GTR) in 83 cases (54.4%), near-total resection (NTR) in 13 cases (9%), partial resection (PTR) in 51 cases (33.3%). 5 cases were biopsies (3.2%). Gamma Knife Surgery was performed in 10 cases (6.5%), all recurrences. At 6 months GOS revealed: Good Recovery 70 cases (46.2%), Moderate Disability 62 cases (40.7%), Severe Disability 13 (8.5%), Vegetative State 2 cases (1.3%), Deceased 5 cases (3.2%). Complications were: diabetes insipidus (89.3%); hypopituitarism (66.4%); hypothalamic damage (17.7%); visual deterioration (18.4%).

CONCLUSIONS

Surgery remains the main option, but GTR complications prove the necessity for a multidisciplinary approach. Outcome predicting factors are: age, tumor size, hydrocephalus degree, hypothalamic dysfunction.

The Medical Therapy of Craniopharyngiomas: The Way Ahead

CONTEXT

Craniopharyngiomas, which are categorized as adamantinomatous (ACPs) or papillary (PCPs), have traditionally been treated with surgery and/or radiotherapy, although when the tumors progress or recur, therapeutic possibilities are very limited. Following recent advances in their molecular pathogenesis, new medical therapeutic options have emerged.

EVIDENCE ACQUISITION

The search strategy that we selected to identify the appropriate evidence involved the following medical subject headings (MeSH) terms: ("Craniopharyngioma" [MeSH] AND "Craniopharyngioma/drug therapy" [MeSH]) NOT ("review" [Publication Type] OR "review literature as topic" [MeSH Terms] OR "review" [All Fields]) AND ("2009/05/01" [PDat]: "2019/04/28" [PDat]).

EVIDENCE SYNTHESIS

Mutations of β-catenin causing Wnt activation with alterations of the MEK/ERK pathway are encountered in the great majority of patients with ACPs; specific alterations also stratify patients to a more aggressive behavior. In most PCPs there is primary activation of the Ras/Raf/MEK/ERK pathway secondary to BRAF-V600E mutations. BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCPs producing clinically useful and, in some cases, sustained responses. In contrast to PCPs, drugs targeting β-catenin and its downstream MAPK pathway in ACPs have so far only been used in in vitro studies, but there appear to be promising new targets clinically.

CONCLUSIONS

The identification of specific genetic alterations in patients with craniopharyngiomas has expanded the therapeutic options, providing evidence for a customized approach using newer molecular agents. More studies including a larger number of carefully selected patients are required to evaluate the response to currently available and evolving agents alone and in combination.

Investigating the Protein Signature of Adamantinomatous Craniopharyngioma Pediatric Brain Tumor Tissue: Towards the Comprehension of Its Aggressive Behavior

Although histologically benign, adamantinomatous craniopharyngioma (AC) pediatric brain tumor is a locally aggressive disease that frequently determines symptoms and hormonal dysfunctions related to the mass effect on the surrounding structures. Another typical feature of this benign neoplasm is the presence of voluminous liquid cysts frequently associated with the solid component. Even if studies have been devoted to the proteomic characterization of the tumor intracystic fluid, poor explorations have been performed on its solid part, principally investigated by transcriptomics technologies. In the present study, seven specimens of AC whole tumor tissue have been analyzed by LC-MS for a preliminary assessment of the proteomic profile by a top-down/bottom-up integrated approach. Thymosin beta 4, ubiquitin, calmodulin, S100 proteins, prothymosin α isoform 2, alpha-defensins 1-4, and fragments largely belonging to vimentin, hemoglobin, and glial fibrillary acidic protein characterized the intact proteome. The identification of alpha-defensins, formerly characterized in AC intracystic fluid, reinforces the hypothesis of a role for inflammation in tumor pathogenesis. A total number of 1798 unique elements were identified by a bottom-up approach with a special focus on the 433 proteins commonly characterized in the 85.7% of the samples analyzed. Their gene ontology classification evidenced the involvement of the adherence system, intermediate filaments, and actin cytoskeleton in tumor pathogenesis and of elements part of the Wnt, FGF, and EGFR signaling pathways. In addition, proteins involved in calcium modulation, innate immunity, inflammation, CCKR and integrin signaling, and gonadotropin-releasing hormone receptor pathways were also outlined. Further than confirming proteomic data previously obtained on AC intracystic fluid, these results offer a preliminary overview of the AC whole tissue protein phenotype, adding new hints towards the comprehension of this still obscure pediatric brain tumor.

The distinct role of strand-specific miR-514b-3p and miR-514b-5p in colorectal cancer metastasis

The abnormal expression of microRNAs (miRNAs) in colorectal cancer (CRC) progression has been widely investigated. It was reported that the same hairpin RNA structure could generate mature products from each strand, termed 5p and 3p, which binds different target mRNAs. Here, we explored the expression, functions, and mechanisms of miR-514b-3p and miR-514b-5p in CRC cells and tissues. We found that miR-514b-3p was significantly down-regulated in CRC samples, and the ratio of miR-514b-3p/miR-514b-5p increased from advanced CRC, early CRC to matched normal colorectal tissues. Follow-up functional experiments illustrated that miR-514b-3p and miR-514b-5p had distinct effects through interacting with different target genes: MiR-514b-3p reduced CRC cell migration, invasion and drug resistance through increasing epithelial marker and decreasing mesenchymal marker expressions, conversely, miR-514b-5p exerted its pro-metastatic properties in CRC by promoting EMT progression. MiR-514b-3p overexpressing CRC cells developed tumors more slowly in mice compared with control cells, however, miR-514b-5p accelerated tumor metastasis. Overall, our data indicated that though miR-514b-3p and miR-514b-5p were transcribed from the same RNA hairpin, each microRNA has distinct effect on CRC metastasis.

Rathke's Cleft Cyst as Origin of a Pediatric Papillary Craniopharyngioma

A 6-year old patient presented with an intra and suprasellar cystic lesion accompanied with impairment of the hypothalamic-pituitary axis and partial hypopituitarism. The most likely cause of sellar lesions in this age group are adamantinomatous craniopharyngioma (adaCP) or Rathke´s cleft cysts (RCCs). AdaCP are characterized by CTNNB1 mutations accompanied with aberrant nuclear beta-catenin expression. RCC show neither nuclear beta-catenin expression nor BRAF mutation. The latter is a hallmark of papillary craniopharyngiomas (papCP) that exhibit remarkable histological similarity with metaplasia of RCC. Diagnosis of the patient was elucidated by CTNNB1 and BRAF mutation screening, utilizing different approaches, as well as histological examination of markers, e.g., beta-catenin, claudin-1, EpCAM and the mutated BRAFV600E protein, which are known to be differentially expressed in sellar lesions. The case presented reveals extraordinary aspects for two reasons. Firstly, the lesion appeared clinically, on MRI, intraoperatively and histologically as RCC with prominent squamous metaplasia, but showing an expression pattern of markers also found in papCP, whilst exhibiting a hitherto undescribed BRAFV600E mutation. This important result documents a supposable transition of RCC metaplasia into a papillary craniopharyngioma (papCP). Secondly, this intriguing case shows unexpectedly that although papCP usually occurs almost exclusively in adults, it can also arise in childhood.

Cystic Craniopharyngiomas: Microsurgical or Stereotactic Treatment?

BACKGROUND

Prognosis and treatment of cystic craniopharyngiomas are poorly defined.

OBJECTIVE

To analyze progression-free survival (PFS) and safety profile of cystic craniopharyngiomas undergoing resection or minimally invasive drainage procedures. We compared further outcome measurements for cystic and solid tumors undergoing resection to elucidate the impact of the initial tumor composition on both PFS and the toxicity profile.

METHODS

All patients with craniopharyngiomas consecutively treated between 1999 and 2014 were included. A treatment decision in favor of microsurgery or stereotactic treatment was made interdisciplinarily. For stereotactic drainage, a catheter was implanted, allowing both permanent upstream (into ventricular spaces) and downstream (into prepontine cistern) drainage. Study endpoints were tumor progression, functional outcome, and treatment toxicity. Functional endocrinological and visual outcome analyses referred to data obtained preoperatively and 6 weeks after treatment. The Kaplan-Meier method was used for survival analysis. Prognostic factors were obtained from proportional hazard models.

RESULTS

Seventy-nine patients were included. The distribution of clinical and tumor-related data was well balanced among patients with solid (n = 35) and cystic (n = 44) tumors and those undergoing microsurgical or stereotactic treatment. Cystic tumors had shorter PFS (5-year PFS: 53.6% vs 66.8%, P = .10) and needed significantly more therapeutic interventions, which was independent of the initial treatment mode. The endocrinological deterioration rate was high for both solid and cystic tumors after microsurgery (59.4% and 85.7%, respectively), whereas it was significantly lower for cystic tumors undergoing stereotactic treatment (23.1%, P < .001).

CONCLUSION

Stereotactic bidirectional drainage of cystic craniopharyngiomas is effective and provides a better endocrinological outcome than conventional microsurgery.

Recent advances in molecular pathology of craniopharyngioma

Craniopharyngiomas are rare epithelial tumours arising along the path of the craniopharyngeal duct. Two major histological subtypes have been recognised, the papillary and the adamantinomatous. Craniopharyngiomas remain challenging tumours to manage and are associated with significant morbidities and mortality. Recent advances in the molecular pathology of these neoplasms have identified BRAF mutations in the papillary variant, offering promising options for targeted pharmacological treatment. The involvement of β-catenin and the Wnt pathway in the tumorigenesis of the adamantinomatous subtype has been previously established with the identification of stabilising mutations in exon 3 of CTNNB1. Further understanding of the pathogenesis of this subtype has been facilitated with the use of mouse models and xenograft experiments. It has been proposed that the clusters of cells with upregulated Wnt/β-catenin signalling induce tumour formation in a paracrine manner; the complex interactions occurring between different cell populations need to be further clarified for further expansion of this hypothesis. This review outlines recent key advances in our understanding of the molecular pathology of craniopharyngiomas and discusses some of the challenges that need to be overcome for the development of targeted therapies that will hopefully improve the management and the outcomes of these patients.

Gene expression profiling to predict recurrence of advanced squamous cell carcinoma of the tongue: discovery and external validation

OBJECTIVES

To establish a prognostic signature for locally advanced tongue squamous cell carcinoma (TSCC) patients treated with surgery.

RESULTS

In the discovery study, unsupervised hierarchical clustering analysis identified two clusters which differentiated the Kaplan-Meier curves of RFS [median RFS, 111 days vs. not reached; log-rank test, P = 0.023]. The 30 genes identified were combined into a dichotomous PI. In the validation cohort, classification according to the PI was associated with RFS [median RFS, 754 days vs. not reached; log-rank test, P = 0.026 in GSE31056] and DSS [median DSS, 540 days vs. not reached; log-rank test, P = 0.046 in GSE42743 and 443 days vs. not reached; P < 0.001 in GSE41613]. Among genes, positive immunohistochemical staining of cytokeratin 4 was associated with favorable prognostic values for RFS (hazard ratio (HR), 0.591, P = 0.045) and DSS (HR, 0.333, P = 0.004).

MATERIALS AND METHODS

We conducted gene expression profiling of 26 clinicopathologically homogeneous advanced TSCC tissue samples using cDNA microarray as a discovery study. Candidate genes were screened using clustering analysis and univariate Cox regression analysis for relapse-free survival (RFS). These were combined into a prognostic index (PI), which was validated using three public microarray datasets of tongue and oral cancer (123 patients). Some genes identified in discovery were immunohistochemically examined for protein expression in another 127 TSCC patients.

CONCLUSION

We identified robust molecular markers that showed significant associations with prognosis in TSCC patients. Gene expression profiling data were successfully converted to protein expression profiling data.

Genomic Alterations of Adamantinomatous and Papillary Craniopharyngioma

Craniopharyngiomas are rare histologically benign but clinically challenging neoplasms. To obtain further information on the molecular genetics and biology of craniopharyngiomas, we analyzed a cohort of 121 adamantinomatous and 16 papillary craniopharyngiomas (ACP, PCP). We extracted DNA from formalin-fixed paraffin-embedded tissue and determined mutational status of CTNNB1, BRAF, and DDX3X by Sanger sequencing, next generation panel sequencing, and pyrosequencing. Sixteen craniopharyngiomas were further analyzed by molecular inversion profiling (MIP); 76.1% of the ACP were mutated in exon 3 of CTNNB1 encoding for β-catenin and there was a trend towards a worse event-free survival in cases mutated at Thr41. Next generation panel sequencing of 26 ACP did not detect any recurrent mutations other than CTNNB1 mutations. BRAF V600E mutations were found in 94% of the PCP, but not in ACP. GISTIC analysis of MIP data showed no significant larger chromosomal aberrations but a fraction of ACP showed recurrent focal gains of chromosomal material, other cases showed loss in the chromosomal region Xq28, and a third group and the PCP had stable genomes. In conclusion, the crucial pathogenetic event appears to be WNT activation in ACP, whereas it appears to be activation of the Ras/Raf/MEK/ERK pathway by BRAF V600E mutations in PCP.

New outlook on the diagnosis, treatment and follow-up of childhood-onset craniopharyngioma

Childhood-onset craniopharyngiomas are rare embryonic tumours of low-grade histological malignancy. Novel insights into the molecular pathogenesis of human adamantinomatous craniopharyngioma have started to unveil the possibility of testing novel treatments targeting pathogenic pathways. Hypothalamic involvement and/or treatment-related lesions result in impaired physical and social functionality and in severe neuroendocrine sequelae. Quality of survival in patients with craniopharyngioma with hypothalamic involvement is impaired by severe obesity, physical fatigue and non-optimal psychosocial development. Patients with craniopharyngioma involving hypothalamic structures have reduced 20-year overall survival, but overall and progression-free survival are not related to the degree of surgical resection. Irradiation is effective in the prevention of tumour progression and recurrence. For favourably localized craniopharyngiomas, the preferred treatment of choice is to attempt complete resection with preservation of visual, hypothalamic and pituitary function. For unfavourably localized tumours in close proximity to optic and/or hypothalamic structures, a radical neurosurgical strategy attempting complete resection is not recommended owing to potential severe sequelae. As expertise has been shown to have an impact on post-treatment morbidity, medical societies should establish criteria for adequate professional expertise for the treatment of craniopharyngioma. On the basis of these criteria, health authorities should organize the certification of centres of excellence that are authorized to treat and care for patients with this chronic disease.

Models of human adamantinomatous craniopharyngioma tissue: Steps toward an effective adjuvant treatment

Even though ACP is a benign tumor, treatment is challenging because of the tumor's eloquent location. Today, with the exception of surgical intervention and irradiation, further treatment options are limited. However, ongoing molecular research in this field provides insights into the pathways involved in ACP pathogenesis and reveal a plethora of druggable targets. In the next step, appropriate models are essential to identify the most suitable and effective substances for clinical practice. Primary cell cultures in low passages provide a proper and rapid tool for initial drug potency testing. The patient-derived xenograft (PDX) model accommodates ACP complexity in that it shows respect to the preserved architecture and similar histological appearance to human tumors and therefore provides the most appropriate means for analyzing pharmacological efficacy. Nevertheless, further research is needed to understand in more detail the biological background of ACP pathogenesis, which provides the identification of the best targets in the hierarchy of signaling cascades. ACP models are also important for the continuous testing of new targeting drugs, to establish precision medicine.

Potassium Homeostasis, Oxidative Stress, and Human Disease

Potassium is the most abundant cation in the intracellular fluid and it plays a vital role in the maintenance of normal cell functions. Thus, potassium homeostasis across the cell membrane, is very critical because a tilt in this balance can result in different diseases that could be life threatening. Both Oxidative stress (OS) and potassium imbalance can cause life threatening health conditions. OS and abnormalities in potassium channel have been reported in neurodegenerative diseases. This review highlights the major factors involved in potassium homeostasis (dietary, hormonal, genetic, and physiologic influences), and discusses the major diseases and abnormalities associated with potassium imbalance including hypokalemia, hyperkalemia, hypertension, chronic kidney disease, and Gordon's syndrome, Bartter syndrome, and Gitelman syndrome.

Molecular pathology of adamantinomatous craniopharyngioma: review and opportunities for practice

Since the first identification of CTNNB1 mutations in adamantinomatous craniopharyngioma (ACP), much has been learned about the molecular pathways and processes that are disrupted in ACP pathogenesis. To date this understanding has not translated into tangible patient benefit.

The recent development of novel techniques and a range of preclinical models now provides an opportunity to begin to support treatment decisions and develop new therapeutics based on molecular pathology.

In this review the authors summarize many of the key findings and pathways implicated in ACP pathogenesis and discuss the challenges that need to be tackled to translate these basic science findings for the benefit of patients.

EpCAM (CD326) is differentially expressed in craniopharyngioma subtypes and Rathke's cleft cysts

The epithelial cell adhesion molecule (EpCAM) is a type I glycoprotein located on the surface of epithelial cells. It is strongly expressed in many neoplasms and already used in the diagnosis and distinction of various tumour subtypes. Comparative studies about EpCAM expression in cystic sellar lesions are lacking. Therefore, we analysed its distribution pattern in adamantinomatous (aCP) and papillary (pCP) craniopharyngiomas (CP) and Rathke’s Cleft Cysts (RCC) using immunohistochemistry and gene expression profiling. Whereas the protein was not detectable in pCP (n = 10), all aCP (n = 64) showed distinct staining patterns. The vast majority of RCC (n = 10) also appeared positive, but these displayed notably lower labeling scores. Additionally, significantly higher mRNA levels were detectable in aCP (n = 19) when compared to pCP (n = 10) (p = 9.985⁻⁸). Furthermore, pediatric aCP cases, in general, exhibited stronger EpCAM staining levels compared to adult ones (p = 0.015). However, we were not able to verify this result on mRNA level. In summary, our findings demonstrate that EpCAM can be used as an additional distinction-marker for cystic lesions of the sellar region. Its unknown function in aCP and the presence of an approved monoclonal bispecific trifunctional antibody for cancer therapy are interesting starting points for further studies.

Novel technique for high-precision stereotactic irradiation of mouse brains

BACKGROUND AND PURPOSE

Small animal irradiation systems were developed for preclinical evaluation of tumor therapy closely resembling the clinical situation. Mostly only clinical LINACs are available, so protocols for small animal partial body irradiation using a conventional clinical system are essential. This study defines a protocol for conformal brain tumor irradiations in mice.

MATERIALS AND METHODS

CT and MRI images were used to demarcate the target volume and organs at risk. Three 6 MV photon beams were planned for a total dose of 10 fractions of 1.8 Gy. The mouse position in a dedicated applicator was verified by an X‑ray patient positioning system before each irradiation. Dosimetric verifications (using ionization chambers and films) were performed. Irradiation-induced DNA damage was analyzed to verify the treatment effects on the cellular level.

RESULTS

The defined treatment protocol and the applied fractionation scheme were feasible. The in-house developed applicator was suitable for individual positioning at submillimeter accuracy of anesthetized mice during irradiation, altogether performed in less than 10 min. All mice tolerated the treatment well. Measured dose values perfectly matched the nominal values from treatment planning. Cellular response was restricted to the target volume.

CONCLUSION

Clinical LINAC-based irradiations of mice offer the potential to treat orthotopic tumors conformably. Especially with respect to lateral penumbra, dedicated small animal irradiation systems exceed the clinical LINAC solution.

Claudin-1 correlates with poor prognosis in lung adenocarcinoma

BACKGROUND

This study was conducted to investigate the clinical significance of claudin-1 (CLDN1) expression in patients with lung adenocarcinoma.

METHODS

We examined CLDN1 protein expression by immunohistochemistry in a tissue microarray from 258 patients with lung adenocarcinoma. We investigated messenger ribonucleic acid (mRNA) expression in H358 (formerly bronchioloalveolar carcinoma) and lung adenocarcinoma cell lines (A549) by real-time reverse transcriptase-polymerase chain reaction.

RESULTS

Multivariate analysis showed that prognostic factors for lung adenocarcinoma were histologic type, CLDN1, T stage and N stage. Patients with positive CLDN1 expression had a poorer prognosis than patients with negative CLDN1 expression. CLDN1 expression was correlated with Ras and epidermal growth factor receptor (EGFR) expression. Patients with positive expressions of both CLDN1 and Ras/EGFR had a poorer prognosis than patients with CLDN1 (+) Ras/EGFR(-) or CLDN1 (-) Ras/EGFR(+) and patients with negative expressions of both CLDN1 and Ras/EGFR. CLDN1 mRNA expression was lower in the H358 compared with the lung adenocarcinoma cell line (A549).

CONCLUSION

The combination of CLDN1 and Ras/EGFR is a valuable independent prognostic predictor for lung adenocarcinoma.

ENDOCRINE TUMORS: BRAF V600E mutations in papillary craniopharyngioma

Papillary craniopharyngioma (PCP) is an intracranial tumor that results in high levels of morbidity. We recently demonstrated that the vast majority of these tumors harbor the oncogenic BRAF V600E mutation. The pathologic diagnosis of PCP can now be confirmed using mutation specific immunohistochemistry and targeted genetic testing. Treatment with targeted agents is now also a possibility in select situations. We recently reported a patient with a multiply recurrent PCP in whom targeting both BRAF and MEK resulted in a dramatic therapeutic response with a marked anti-tumor immune response. This work shows that activation of the MAPK pathway is the likely principal oncogenic driver of these tumors. We will now investigate the efficacy of this approach in a multicenter phase II clinical trial. Post-treatment resection samples will be monitored for the emergence of resistance mechanisms. Further advances in the non-invasive diagnosis of PCP by radiologic criteria and by cell-free DNA testing could someday allow neo-adjuvant therapy for this disease in select patient populations.

Adamantinomatous and papillary craniopharyngiomas are characterized by distinct epigenomic as well as mutational and transcriptomic profiles

Introduction

Craniopharyngiomas (CP) are rare epithelial tumors of the sellar region. Two subtypes, adamantinomatous (adaCP) and papillary CP (papCP), were previously identified based on histomorphological and epidemiological aspects. Recent data indicates that both variants are defined by specific genetic alterations, and influenced by distinct molecular pathways and particular origins. The fact that CP is an uncommon tumor entity renders studies on large cohorts difficult and exceptional. In order to achieve further insights distinguishing CP variants, we conducted whole genome methylation (450 k array) and microarray-based gene expression studies in addition to CTNNB1 and BRAF mutation analysis using a comprehensive cohort of 80 adaCP and 35 papCP.

Results

BRAFV600E mutations were solely found in the papCP subgroup and were not detectable in adaCP samples. In contrast, CTNNB1 mutations were exclusively detected in adaCP. The methylome fingerprints assigned DNA specimens to entity-specific groups (papCP (n = 18); adaCP (n = 25)) matching perfectly with histology-based diagnosis, suggesting that they represent truly distinct biological entities. However, we were not able to detect within the adaCP group (including 11 pediatric and 14 adult cases) a significant difference in methylation signature by age. Integrative comparison of the papCP with the adaCP group based on differential gene expression and methylation revealed a distinct upregulation of Wnt- and SHH signaling pathway genes in adaCP.

Conclusions

AdaCP and papCP thus represent distinct tumor subtypes that harbor mutually exclusive gene mutations and methylation patterns, further reflected in differences in gene expression. This study demonstrates that DNA methylation analyses are an additional method to classify CP into subtypes, and implicates a role of epigenetic mechanisms in the genesis of the respective CP variants. Detection of tumor-specific signaling pathway activation enables the possibility of target-oriented intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s40478-016-0287-6) contains supplementary material, which is available to authorized users.

Systems Proteomics View of the Endogenous Human Claudin Protein Family

Claudins are the major transmembrane protein components of tight junctions in human endothelia and epithelia. Tissue-specific expression of claudin members suggests that this protein family is not only essential for sustaining the role of tight junctions in cell permeability control but also vital in organizing cell contact signaling by protein-protein interactions. How this protein family is collectively processed and regulated is key to understanding the role of junctional proteins in preserving cell identity and tissue integrity. The focus of this review is to first provide a brief overview of the functional context, on the basis of the extensive body of claudin biology research that has been thoroughly reviewed, for endogenous human claudin members and then ascertain existing and future proteomics techniques that may be applicable to systematically characterizing the chemical forms and interacting protein partners of this protein family in human. The ability to elucidate claudin-based signaling networks may provide new insight into cell development and differentiation programs that are crucial to tissue stability and manipulation.

Ultrastructural characterization of craniopharyngioma at the tumor boundary: A structural comparison with an experimental toxic model using "oil machinery" fluid, with emphasis on Rosenthal fibers

Craniopharyngiomas (CPs) are cystic, encapsulated, slow-growing epithelial tumors. CPs can be aggressive forms invading and resorting surrounding structures of adjacent brain tissue, where Rosenthal fibers (RFs) are expressed. The aim of this study was to investigate the ultrastructure of these fibers in human biopsies and compare it with an experimental toxic model produced by the cortical infusion of the oil cyst fluid ("Oil machinery" fluid or OMF) from CPs to rats. For this purpose, the CPs from ten patients were examined by light and electron microscopy. OMF was administered to rats intracortically. Immunohistochemical detection of glial fibrillary acidic protein (GFAP) and vimentin was assessed. In both freshly obtained CPs and rat brain tissue, the presence of abundant cellular debris, lipid-laden macrophages, reactive gliosis, inflammation and extracellular matrix destruction were seen. Ultrastructural results suggest focal pathological disturbances and an altered microenvironment surrounding the tumor-brain junction, with an enhanced presence of RFs in human tumors. In contrast, in the rat brain different degrees of cellular disorganization with aberrant filament-filament interactions and protein aggregation were seen, although RFs were absent. Our immunohistochemical findings in CPs also revealed an enhanced expression of GFAP and vimentin in RFs at the peripheral, but not at the central (body) level. Through these findings we hypothesize that the continuous OMF release at the CPs boundary may cause tissue alterations, including damaging of the extracellular matrix, and possibly contributing to RFs formation, a condition that was not possible to reproduce in the experimental model. The presence of RFs at the CPs boundary might be considered as a major criterion for the degree of CPs invasiveness to normal tissue. The lack of RFs reactivity in the experimental model reveals that the invasive component of CPs is not present in the OMF, although the fluid per se can exert tissue damage.

Molecular and cellular pathogenesis of adamantinomatous craniopharyngioma

Adamantinomatous craniopharyngiomas (ACPs) are the most common pituitary tumours in children. Although histologically benign, these are clinically aggressive tumours, difficult to manage and associated with poor quality of life for the patients. Several human and mouse studies have provided unequivocal evidence that the over-activation of the WNT/β-catenin signalling pathway underlies the molecular aetiology of these tumours. Recently, research using genetically modified mouse models of human ACP have revealed a critical and unexpected non-cell autonomous role for pituitary stem cells in ACP tumourigenesis, which has expanded the cancer stem cell paradigm. As the result of this basic research, the pathogenesis of ACP is being unveiled, with promising implications for the development of novel treatments against these childhood neoplasms. These benign tumours may additionally represent a unique model to provide insights into the initial steps of oncogenesis.

The role of epithelial tight junctions involved in pathogen infections

Tight junctions (TJs) are sealing complexes between adjacent epithelial cells, functioning by controlling paracellular passage and maintaining cell polarity. These functions of TJs are primarily based on structural integrity as well as dynamic regulatory balance, indicating plasticity of TJ in response to external stimuli. An indispensable role of TJs involved in pathogen infection has been widely demonstrated since disruption of TJs leads to a distinct increase in paracellular permeability and polarity defects which facilitate viral or bacterial entry and spread. In addition to pathological changes in TJ integrity, TJ proteins such as occludin and claudins can either function as receptors for pathogen entry or interact with viral/bacterial effector molecules as an essential step for characterizing an infective stage. This suggests a more complicated role for TJ itself and especially specific TJ components. Thus, this review surveys the role of the epithelial TJs involved in various pathogen infections, and extends TJ targeted therapeutic and pharmacological application prospects.

Insights into the infiltrative behavior of adamantinomatous craniopharyngioma in a new xenotransplant mouse model

Adamantinomatous craniopharyngiomas (adaCP) cause hypothalamic pituitary dysfunction. Elucidation of pathomechanisms underlying tumor progression is essential for the development of targeted chemotherapeutic treatment options. In order to study the mechanisms of tumor outgrowth, we implanted human primary adaCP tissue from three different surgical specimens stereotactically into the brain of immunodeficient mice (n = 20). Three months after tumor inoculation, magnetic resonance imaging and histology confirmed tumor engraftment in all 20 mice (100%) that obtained tissue transplants. The lesions invaded adjoining brain tissue with micro finger-shaped protrusions. Immunohistochemical comparison of the primary tumor and xenotransplants revealed a similar amount of proliferation (Mib-1) and cytokeratin expression pattern (KL-1). Whole tumor reconstruction using serial sections confirmed whirl-like cell clusters with nuclear β-catenin accumulations at the tumor brain border. These whirls were surrounded by a belt of Claudin-1 expressing cells, showed an activated epidermal growth factor receptor (EGFR) and distinct CD133 as well as p21(WAF1/Cip1) positivity, indicating a tumor stem cell phenotype. Consistent with our previous in vitro studies, intracranial xenotransplants of adaCP confirmed cells with nuclear β-catenin and activated EGFR being the driving force of tumor outgrowth. This model provides the possibility to study in vivo tumor cell migration and to test novel treatment regimens targeting this tumor stem cell niche.