Microtubule-associated Protein-2 is a Sensitive Marker of Primary and Metastatic Neuroblastoma

Nerve Density and Neuronal Biomarkers in Cancer

Simple Summary

Researchers have shown that tumor biomarkers and increased nerve density are important clinical tools for determining cancer prognosis and developing effective treatments. The aims of our review were to synthesize these findings by detailing the histology of peripheral nerves, discuss the use of various neuronal biomarkers in cancer, and assess the impact of increased nerve density on tumorigenesis. This review demonstrates that specific neuronal markers may have an important role in tumorigenesis and may serve as diagnostic and prognostic factors for various cancers. Moreover, increased nerve density may be associated with worse prognosis in different cancers, and cancer therapies that decrease nerve density may offer benefit to patients.

Abstract

Certain histologic characteristics of neurons, novel neuronal biomarkers, and nerve density are emerging as important diagnostic and prognostic tools in several cancers. The tumor microenvironment has long been known to promote tumor development via promoting angiogenesis and cellular proliferation, but new evidence has shown that neural proliferation and invasion in the tumor microenvironment may also enable tumor growth. Specific neuronal components in peripheral nerves and their localization in certain tumor sites have been identified and associated with tumor aggressiveness. In addition, dense neural innervation has been shown to promote tumorigenesis. In this review, we will summarize the histological components of a nerve, explore the neuronal biomarkers found in tumor sites, and discuss clinical correlates between tumor neurobiology and patient prognosis.

INSM1 Expression in Peripheral Neuroblastic Tumors and Other Embryonal Neoplasms

Insulinoma-associated protein 1 (INSM1) is a transcription factor that functions in neuroepithelial tissue development and shows expression in neuroendocrine neoplasms. Given the role of INSM1 in controlling differentiation of the sympatho-adrenal lineage, we hypothesized that INSM1 expression would define a subset of neuroblastic tumors. This study aimed to characterize the immunohistochemical profile of INSM1 in a cohort of peripheral neuroblastic tumors and compare INSM1 expression in these tumors to that seen in other embryonal neoplasms, using both tissue microarrays and whole-slide histologic sections. INSM1 showed nuclear expression in 39/50 (78%) peripheral neuroblastic tumors, including 27/32 (84%) neuroblastomas, 9/9 (100%) ganglioneuroblastomas, and 3/9 (33%) ganglioneuromas. Altogether, 70% of peripheral neuroblastic tumors showed anti-INSM1 immunoreactivity in more than 20% of tumor nuclei. Although no non-neuroblastic tumors in this study exhibited INSM1 expression in more than 20% of nuclei, focal or patchy staining was identified in 7/14 (50%) rhabdomyosarcomas, 7/22 (32%) nephroblastomas, and 4/20 (20%) Ewing sarcomas. The absence of INSM1 expression in peripheral neuroblastic tumors was restricted to undifferentiated and poorly differentiated neuroblastomas, as well as mature ganglioneuromas, mimicking the transient INSM1 expression seen in sympatho-adrenal differentiation during normal development. No significant association between MYCN amplification status and INSM1 expression was observed. We found that all 3 INSM1-negative neuroblastoma patients with available follow-up were alive at a median of 15 years, in comparison to 9 of 13 INSM1-positive neuroblastoma patients living at a median of 5 years. Additional studies are needed to determine whether INSM1 expression is indicative of a clinically significant differentiation state in neuroblastoma.

Patient-Derived Xenograft Models Reveal Intratumor Heterogeneity and Temporal Stability in Neuroblastoma

Patient-derived xenografts (PDX) and the Avatar, a single PDX mirroring an individual patient, are emerging tools in preclinical cancer research. However, the consequences of intratumor heterogeneity for PDX modeling of biomarkers, target identification, and treatment decisions remain underexplored. In this study, we undertook serial passaging and comprehensive molecular analysis of neuroblastoma orthotopic PDXs, which revealed strong intrinsic genetic, transcriptional, and phenotypic stability for more than 2 years. The PDXs showed preserved neuroblastoma-associated gene signatures that correlated with poor clinical outcome in a large cohort of patients with neuroblastoma. Furthermore, we captured spatial intratumor heterogeneity using ten PDXs from a single high-risk patient tumor. We observed diverse growth rates, transcriptional, proteomic, and phosphoproteomic profiles. PDX-derived transcriptional profiles were associated with diverse clinical characteristics in patients with high-risk neuroblastoma. These data suggest that high-risk neuroblastoma contains elements of both temporal stability and spatial intratumor heterogeneity, the latter of which complicates clinical translation of personalized PDX-Avatar studies into preclinical cancer research.Significance: These findings underpin the complexity of PDX modeling as a means to advance translational applications against neuroblastoma. Cancer Res; 78(20); 5958-69. ©2018 AACR.

miR-484/MAP2/c-Myc-positive regulatory loop in glioma promotes tumor-initiating properties through ERK1/2 signaling

Glioma is the most common intracranial malignant tumor. Cancer stem cells (CSCs) are resistant to chemotherapy and radiotherapy, and are closely related to cancer metastasis and recurrence. In this study, we aimed to explore the effect of miR-484 on glioma stemness and the underlying mechanism involved. miR-484 enhanced glioma tumor-initiating properties in vitro and in vivo. Moreover, miR-484 was shown to directly target MAP2, resulting in activation of ERK1/2 signaling and promotion of stemness in glioma. The ERK1/2 signaling facilitated the formation of a miR-484/MAP2/c-Myc positive feedback loop in glioma. High miR-484 expression predicted a poor prognosis for glioma patients, and high MAP2 expression predicted a good prognosis for glioma patients. Low miR-484 expression and high MAP2 expression was associated with the best prognosis in glioma. Our study suggests that miR-484 and MAP2 can be utilized as predictors for the clinical diagnosis and prognosis of glioma, and miR-484 and MAP2 are potential targets for the treatment of glioma.

Immunohistochemical Profile of MYC Protein in Pediatric Small Round Blue Cell Tumors

Deregulation of MYC oncoprotein in cancers can result from multiple oncogenic mechanisms. Although MYC translocations define Burkitt lymphoma and MYC protein expression is a poor prognostic factor in undifferentiated neuroblastomas, the distribution of MYC protein (c-MYC) across other pediatric small round blue cell tumors (SRBCT) has not been well characterized. We undertook this study to assess MYC protein expression in a large cohort of pediatric lymphomas, sarcomas, and other SRBCT. Tissue microarrays containing 302 SRBCT were successfully evaluated by immunohistochemistry using anti-MYC clone Y69, with nuclear positivity scored as 0%, 1%-25%, 26%-50%, 51%-75%, or 76%-100%. MYC protein staining of >50% of lesional cells was identified in 60% of Burkitt lymphomas, 50% of B lymphoblastic lymphomas, 33% of T lymphoblastic lymphomas, 31% of rhabdomyosarcomas, 33% of Ewing sarcomas, and 25% of soft tissue sarcomas, not otherwise specified. Only 14% of neuroblastomas showed >50% staining, and of these, if known, MYCN was not amplified. No cases of Wilms tumor, synovial sarcoma, or desmoplastic small round cell tumor had >50% staining. Recurrences and metastases often had the same percentage of MYC staining (15/30). In conclusion, MYC protein exhibited variable expression across and within pediatric SRBCT subtypes. Overall, these findings provide a baseline for MYC expression in pediatric SRBCT and suggest that there may be multiple mechanisms of MYC upregulation in these different neoplasms.

Improving Detection of Metastatic Neuroblastoma in Bone Marrow Core Biopsies: A Proposed Immunohistochemical Approach

Bone marrow (BM) nvolvement is common in stage 4/M neuroblastoma patients and profoundly impacts clinical decision-making and predicts outcomes, but to our knowledge no standard exists for immunohistochemical evaluation of staging BMs. We examined the use of three immuno-stains-synaptophysin, tyrosine hydroxylase (TH), and PGP9.5-in detecting metastatic neuroblastoma in BM. We retrospectively selected 174 BM core biopsies from 41 neuroblastoma patients. Immunohistochemistry for synaptophysin, TH, and PGP9.5 was performed. These slides and the hematoxylin and eosin (H&E)-stained slide from each BM were randomized and independently scored by three pathologists as positive, negative, or indeterminate. Cohen's κ coefficients (interobserver agreement), McNemar's test (for frequencies of positive/indeterminate interpretations), and sensitivities for each stain/combination were calculated. Interobserver agreement was higher for all immunostains (synaptophysin, 78%-90%, κ  =  0.548-0.787; TH, 77%-92%, κ  =  0.481-0.788; and PGP9.5, 83%-90%, κ  =  0.601-0.740) than for H&Es (77%-84%, κ  =  0.434-0.572). Indeterminate interpretations were more frequent with H&Es (8.9%) and synaptophysin (6.0%) than with PGP9.5 (3.5%) or TH (3.3%). TH (76%) and PGP9.5 (70%) were the immunostains most likely to correctly resolve indeterminate H&E interpretation. Mean sensitivity among all three pathologists for detection of metastasis compared to the consensus diagnosis was 42.5% for H&E alone, 70.7% to 78.8% for H&E plus one immunostain, and 81.6% to 85% for H&E plus two immunostains. Immunohistochemistry enhanced sensitivity for tumor detection particularly dramatically in cases of prior chemotherapy. PGP9.5 and TH showed good interobserver agreement, fewer indeterminate interpretations, and resolved indeterminate H&E diagnoses at the highest frequencies. Therefore, we recommend H&E and two immunostains, specifically PGP9.5 and TH, for optimal detection of metastatic neuroblastoma in BM.

A novel 96-well multielectrode array based impedimetric monitoring platform for comparative drug efficacy analysis on 2D and 3D brain tumor cultures

Aggressive cancer entities like neuroblastoma and glioblastoma multiforme are still difficult to treat and have discouraging prognosis in malignant stage. Since each tumor has its own characteristics concerning the sensitivity towards different chemotherapeutics and moreover, can obtain resistance, the development of novel chemotherapeutics with a broad activity spectrum, high efficacy and minimum side effects is a continuous process. Sophisticated in vitro assays for comprehensive prediction of in vivo drug efficacy and side effects represent an actual bottleneck in the drug development process. In this context, we developed a novel in vitro 2D and 3D multiwell-multielectrode device for drug efficacy monitoring based on direct real-time impedance spectroscopy measurement in combination with our unique 96-well multielectrode arrays and microcavity arrays. For demonstration, we used three neuro- and glioblastoma cell lines that were cultured as monolayer and multicellular tumor spheroids for recapitulating in vivo conditions. Using our novel 96-well multielectrode array based system it was possible to detect time and concentration dependent responses concerning treatment with doxorubicin, etoposide and vincristine. While all tested chemotherapeutics revealed high potency for apoptosis induction in neuroblastoma cells, etoposide was ineffective for glioblastoma cell lines. Determination of IC50 values allowed us to compare drug efficacy in 2D and 3D culture models and moreover, revealed chemotherapeutic and tumor cell line specific activity patterns. These pharmacokinetic patterns are of great interest in the context of preclinical drug development. Thus, impedance spectroscopy based monitoring systems could be used for the fast in vitro based in vivo prediction of novel anti-tumor drugs.

Reversible adaptive plasticity: a mechanism for neuroblastoma cell heterogeneity and chemo-resistance

We describe a novel form of tumor cell plasticity characterized by reversible adaptive plasticity in murine and human neuroblastoma. Two cellular phenotypes were defined by their ability to exhibit adhered, anchorage dependent (AD) or sphere forming, anchorage independent (AI) growth. The tumor cells could transition back and forth between the two phenotypes and the transition was dependent on the culture conditions. Both cell phenotypes exhibited stem-like features such as expression of nestin, self-renewal capacity, and mesenchymal differentiation potential. The AI tumorspheres were found to be more resistant to chemotherapy and proliferated slower in vitro compared to the AD cells. Identification of specific molecular markers like MAP2, β-catenin, and PDGFRβ enabled us to characterize and observe both phenotypes in established mouse tumors. Irrespective of the phenotype originally implanted in mice, tumors grown in vivo show phenotypic heterogeneity in molecular marker signatures and are indistinguishable in growth or histologic appearance. Similar molecular marker heterogeneity was demonstrated in primary human tumor specimens. Chemotherapy or growth factor receptor inhibition slowed tumor growth in mice and promoted initial loss of AD or AI heterogeneity, respectively. Simultaneous targeting of both phenotypes led to further tumor growth delay with emergence of new unique phenotypes. Our results demonstrate that neuroblastoma cells are plastic, dynamic, and may optimize their ability to survive by changing their phenotype. Phenotypic switching appears to be an adaptive mechanism to unfavorable selection pressure and could explain the phenotypic and functional heterogeneity of neuroblastoma.

Serum-autoantibodies for discovery of prostate cancer specific biomarkers

BACKGROUND

The currently used prostate cancer serum marker has a low cancer specificity and improved diagnostics are needed. Here we evaluated whether autoantibodies are present in sera of prostate cancer patients and whether they are useful diagnostic markers for prostate cancer.

METHODS

Sera from 20 prostate cancer patients and 20 healthy controls were incubated on expression clone arrays containing more than 37,000 recombinant human proteins. Functional annotation clustering of the identified autoantigens was performed using the DAVID database. Autoantigens identified in the prostate cancer group were validated on microarrays using sera of 40 prostate cancer patients, 40 patients with elevated PSA levels but prostate cancer negative biopsies (benign disease), and 40 healthy controls.

RESULTS

We detected autoantibodies against 408 different antigens in sera of prostate cancer patients. One hundred seventy-four of these were exclusively detected in the cancer group compared to the healthy control group. Functional annotation clustering revealed an enrichment of RNA-associated, cytoskeleton, and nuclear proteins. The autoantibody panel was validated in serum samples of independent prostate cancer patients. Autoantibody profiles discriminated between prostate cancer patients and benign disease patients with an ROC curve AUC of 0.71. TTLL12, a protein recently described to be over-expressed in prostate cancer, was the highest ranked discrimination autoantigen.

CONCLUSION

A variety of autoantibodies were identified in sera of prostate cancer patients and provide a first step towards autoantibody diagnostics. Serum autoantibodies reflect the disease and represent valuable tools not only for prostate cancer, but also for other diseases affecting the immune response.

MYB expression and translocation in adenoid cystic carcinomas and other salivary gland tumors with clinicopathologic correlation

BACKGROUND

Adenoid cystic carcinoma is a locally aggressive salivary gland neoplasm, which has a poor long-term prognosis. A chromosomal translocation involving the genes encoding the transcription factors, MYB and NFIB, has been recently discovered in these tumors.

METHODS

MYB translocation and protein expression were studied in 37 adenoid cystic carcinomas, 112 other salivary gland neoplasms, and 409 nonsalivary gland neoplasms by fluorescence in situ hybridization and immunohistochemistry. MYB translocation and expression status in adenoid cystic carcinoma was correlated with clinicopathologic features including outcome, with a median follow-up of 77.1 months (range, 23.2 to 217.5 mo) for living patients.

RESULTS

A balanced translocation between MYB and NFIB is present in 49% of adenoid cystic carcinomas but is not identified in other salivary gland tumors or nonsalivary gland neoplasms. There is no apparent translocation of MYB in 35% of the cases. Strong Myb immunostaining is very specific for adenoid cystic carcinomas but is only present in 65% of all cases. It is interesting to note that Myb immunostaining is confined to the basal cell component although the translocation is present in all the cells. Neoplasms with MYB translocation show a trend toward higher local relapse rates, but the results are not statistically significant with the current number of cases.

CONCLUSIONS

MYB translocation and expression are useful diagnostic markers for a subset of adenoid cystic carcinomas. The presence of the translocation may be indicative of local aggressive behavior, but a larger cohort may be required to show statistical significance.

A tissue microarray-based comparative analysis of novel and traditional immunohistochemical markers in the distinction between adrenal cortical lesions and pheochromocytoma

We have encountered an increasing number of image-guided adrenal mass biopsies in which the differential diagnosis is adrenal cortical lesion versus pheochromocytoma. This distinction is sometimes difficult because of confounding clinical presentations, overlapping morphologies, and some degree of immunophenotypic overlap including focal staining with markers of purported lineage specificity. Interventional radiologists commonly use narrow gauge biopsy needles in this setting, which yield scant diagnostic tissue and further complicate pathologic evaluation. In this study, a detailed immunoprofile of 63 adrenal cortical lesions (3 adrenal rests, 6 adrenal cortical hyperplasias, 43 adrenal cortical adenomas, 4 adrenal cortical neoplasms of uncertain malignant potential, and 7 adrenal cortical carcinomas) was compared with 35 pheochromocytomas using traditional (calretinin, chromogranin, inhibin, melanA, and synaptophysin) and novel [steroidogenic factor-1 (SF-1), microtubule-associated protein 2, and mammalian achaete-scute homolog-1] antibodies, using tissue microarray technology to simulate small image-guided biopsies. Staining extent and intensity were each scored semiquantitatively for each antibody. A comparison of sensitivity and specificity using different intensity thresholds required for a "positive" result (> or = 1+ vs. > or = 2+) was performed. Staining results based on a > or = 1+ and (> or = 2+) intensity threshold were as follows: calretinin-95% (89%) in adrenal cortical lesions and 14% (0%) in pheochromocytomas; chromogranin-0% in adrenal cortical lesions and 100% in pheochromocytomas; inhibin-97% (86%) in adrenal cortical lesions and 6% (0%) in pheochromocytomas; microtubule-associated protein 2-29% (16%) in adrenal cortical lesions and 100% (89%) in pheochromocytomas; mammalian achaete-scute homolog-1-0% in both adrenal cortical lesions and pheochromocytomas; melanA-94% (86%) in adrenal cortical lesions and 6% (0%) in pheochromocytomas; SF-1-87% (86%) in adrenal cortical lesions and 0% in pheochromocytomas; synaptophysin-67% (59%) in adrenal cortical lesions and 100% in pheochromocytomas. Using an antibody panel consisting of chromogranin plus the nuclear antibody SF-1 and either calretinin or inhibin, while requiring a high-staining intensity threshold, helps to eliminate interpretative issues of artifactual or background reactivity, improves diagnostic sensitivity/specificity, and makes for an effective immunohistochemical approach in distinguishing adrenal cortical lesions from pheochromocytomas.