Differential expression of S100 protein subtypes in malignant melanoma, and benign and malignant peripheral nerve sheath tumors

Diagnostic SOX10 gene signatures in salivary adenoid cystic and breast basal-like carcinomas

BACKGROUND

Salivary adenoid cystic carcinoma (ACC) is an insidious slow-growing cancer with the propensity to recur and metastasise to distant sites. Basal-like breast carcinoma (BBC) is a molecular subtype that constitutes 15-20% of breast cancers, shares histological similarities and basal cell markers with ACC, lacks expression of ER (oestrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2), and, similar to ACC, metastasises predominantly to the lung and brain. Both cancers lack targeted therapies owing to poor understanding of their molecular drivers.

METHODS

Gene expression profiling, immunohistochemical staining, western blot, RT-PCR, and in silico analysis of massive cancer data sets were used to identify novel markers and potential therapeutic targets for ACC and BBC. For the detection and comparison of gene signatures, we performed co-expression analysis using a recently developed web-based multi-experiment matrix tool for visualisation and rank aggregation.

RESULTS

In ACC and BBC we identified characteristic and overlapping SOX10 gene signatures that contained a large set of novel potential molecular markers. SOX10 was validated as a sensitive diagnostic marker for both cancers and its expression was linked to normal and malignant myoepithelial/basal cells. In ACC, BBC, and melanoma (MEL), SOX10 expression strongly co-segregated with the expression of ROPN1B, GPM6B, COL9A3, and MIA. In ACC and breast cancers, SOX10 expression negatively correlated with FOXA1, a cell identity marker and major regulator of the luminal breast subtype. Diagnostic significance of several conserved elements of the SOX10 signature (MIA, TRIM2, ROPN1, and ROPN1B) was validated on BBC cell lines.

CONCLUSION

SOX10 expression in ACC and BBC appears to be a part of a highly coordinated transcriptional programme characteristic for cancers with basal/myoepithelial features. Comparison between ACC/BBC and other cancers, such as neuroblastomaand MEL, reveals potential molecular markers specific for these cancers that are likely linked to their cell identity. SOX10 as a novel diagnostic marker for ACC and BBC provides important molecular insight into their molecular aetiology and cell origin. Given that SOX10 was recently described as a principal driver of MEL, identification of conserved elements of the SOX10 signatures may help in better understanding of SOX10-related signalling and development of novel diagnostic and therapeutic tools.

Evidence of sympathetic innervation and α1-adrenergic receptors of the long head of the biceps brachii tendon

BACKGROUND

The primary purpose of this study was to investigate the sympathetic innervation of the long head of the biceps brachii tendon LHB via immunohistochemical staining for protein S-100 and neuropeptide Y (NPY) in patients with complex proximal humerus fractures, in individuals with chronic biceps tendinosis in the setting of large rotator cuff tears (RC), and in cadaveric samples with no previously reported shoulder pathology.

METHODS

We investigated the presence of sympathetic innervation and α1-adrenergic receptors of the long head of the biceps brachii tendon (LHB) in patients with complex proximal humerus fractures and individuals with chronic biceps tendinosis in the setting of large rotator cuff tears (RC). The correlation of morphological features with immunohistochemical evidence of neural element presence was also investigated. Forty-one LHB tendon specimens were examined. Seventeen were harvested from patients who underwent hemiarthroplasty for proximal humerus fractures, 14 were from individuals with biceps tendinosis in the context of a large RC tear, and ten were from cadaveric controls with no previous shoulder pathology. Histologic examination was performed using hematoxylin and eosin. Immunohistochemistry was used to detect the expression of the protein S-100, neuropeptide Y, and α1-adrenergic receptors, as well as to characterize the potential neural differentiation of tendon cells.

RESULTS

A strong correlation between the expression of NPY/S-100, α1-adrenergic/S-100, and α1-adrenergic/NPY was found. The LHB tendon has sympathetic innervation and α1-adrenergic receptors in acute and chronic pathological conditions.

CONCLUSION

Our results provide useful guidance on the management of tendinosis and the handling of the LHB in hemiarthroplasties for fractures.

Thermodynamic and kinetic analysis of peptides derived from CapZ, NDR, p53, HDM2, and HDM4 binding to human S100B

S100B is a member of the S100 subfamily of EF-hand proteins that has been implicated in malignant melanoma and neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease. Calcium-induced conformational changes expose a hydrophobic binding cleft, facilitating interactions with a wide variety of nuclear, cytoplasmic, and extracellular target proteins. Previously, peptides derived from CapZ, p53, NDR, HDM2, and HDM4 have been shown to interact with S100B in a calcium-dependent manner. However, the thermodynamic and kinetic basis of these interactions remains largely unknown. To gain further insight, we screened these peptides against the S100B protein using isothermal titration calorimetry and nuclear magnetic resonance. All peptides were found to have binding affinities in the low micromolar to nanomolar range. Binding-induced changes in the line shapes of S100B backbone (1)H and (15)N resonances were monitored to obtain the dissociation constants and the kinetic binding parameters. The large microscopic K(on) rate constants observed in this study (≥1 × 10(7) M(-1) s(-1)) suggest that S100B utilizes a "fly casting mechanism" in the recognition of these peptide targets.

Spontaneous aortic rupture in a patient with neurofibromatosis type 1

Neurofibromatosis type I (NF-1) is a rare autosomal dominant genetic disorder occurring in 1 in 3,000 individuals. Vasculopathy is a rarely reported finding in patients with NF-1. Here, we report a case of recurrent aortic pseudoaneurysm after endovascular aneurysm repair in a 49-year-old male patient with NF-1. On the sixth postoperative day following a successful open surgical repair of an aortic pseudoaneurysm, he developed hemoperitoneum due to a delayed rupture of the mesenteric artery branch. This was treated with endovascular coil embolization. We report the clinical features and histologic findings of this rare vascular disorder with a review of the relevant literature.

Novel biomarkers and therapeutic targets for optimizing the therapeutic management of melanomas

Cutaneous malignant melanoma is the most aggressive form of skin cancer with an extremely poor survival rate for the patients diagnosed with locally invasive and metastatic disease states. Intensive research has led in last few years to an improvement of the early detection and curative treatment of primary cutaneous melanomas that are confined to the skin by tumor surgical resection. However, locally advanced and disseminated melanomas are generally resistant to conventional treatments, including ionizing radiation, systemic chemotherapy, immunotherapy and/or adjuvant stem cell-based therapies, and result in the death of patients. The rapid progression of primary melanomas to locally invasive and/or metastatic disease states remains a major obstacle for an early effective diagnosis and a curative therapeutic intervention for melanoma patients. Importantly, recent advances in the melanoma research have led to the identification of different gene products that are often implicated in the malignant transformation of melanocytic cells into melanoma cells, including melanoma stem/progenitor cells, during melanoma initiation and progression to locally advanced and metastatic disease states. The frequent deregulated genes products encompass the oncogenic B-RafV600E and N-RasQ61R mutants, different receptor tyrosine kinases and developmental pathways such as epidermal growth factor receptor (EGFR), stem cell-like factor (SCF) receptor KIT, hedgehog, Wnt/β-catenin, Notch, stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor-4 (CXCR4) and vascular endothelial growth factor (VEGF)/VEGFR receptor. These growth factors can cooperate to activate distinct tumorigenic downstream signaling elements and epithelial-mesenchymal transition (EMT)-associated molecules, including phosphatidylinositol 3’-kinase (PI3K)/Akt/ molecular target of rapamycin (mTOR), nuclear factor-kappaB (NF-κB), macrophage inhibitory cytokine-1 (MIC-1), vimentin, snail and twist. Of therapeutic relevance, these deregulated signal transduction components constitute new potential biomarkers and therapeutic targets of great clinical interest for improving the efficacy of current diagnostic and prognostic methods and management of patients diagnosed with locally advanced, metastatic and/or relapsed melanomas.

Detection of melanoma using antibody-conjugated quantum dots in a coculture model for high-throughput screening system

We proposed an effective strategy for evaluating the targeting specificity of an antibody-conjugated quantum dot (QD) nanoprobe in a coculture system mimicking an in vivo-like tumor microenvironment in which cancer cells grow with normal cells. Analysis of the images was performed with automated confocal microscopy. We have employed a melanoma-melanocyte coculture model to assess the specific binding of QDs conjugated with melanoma antibodies. Conjugation of antibodies to the QD significantly improved the melanoma specificity, while unconjugated antibody alone suffered from non-specific binding to melanocytes. Concentration-dependent binding and competitive inhibition studies with QD-antibody conjugates reproducibly proved the specificity to melanoma cells against melanocytes. The specificity and targeting efficiency of nanoprobes evaluated in a simple coculture model may provide a reasonable assessment for the in vitro diagnosis of early stage melanoma development before in vivo studies. Further, a rapid and sensitive cancer cell detection system demonstrated herein may allow for the development of high-throughput screening platforms for early cancer diagnosis and anti-cancer therapeutics.

Giant plexiform schwannoma of the tongue

We present the case of a 38-year-old woman that presented with a very slowly enlarging mass of the tongue. MRI revealed a large mass originating in the tongue base and extending to the supraglottic space. Biopsy of this tumor confirmed the diagnosis of schwannoma. An endaural approach allowed complete resection of the tumor. Definitive histopathological examination showed a plexiform schwannoma. Schwannoma or neurilemoma represents a benign tumor potentially affecting any nerve. The head and neck region is a relatively common location for schwannomas, but tongue schwannomas are considered to be rare and pose the problem of both clinical and histological differential diagnosis of tongue masses.

Erdheim-Chester disease: a case study and literature review

Diagnosis and treatment of patients who present with respiratory compromise are challenging. What happens when these patients do not respond to your intervention, and their condition declines rapidly? Having a variety of differential diagnoses is key. An addition to your differential list can include a rare disorder of non-Langerhans cells histiocytosis also known as Erdheim-Chester disease. This disease often presents as an interstitial lung disease that fails many different treatment modalities. A full understanding of how this disease process works is still being investigated. Provided are a literature review and case study for better understanding of this disease.

Perineural extension of cutaneous desmoplastic melanoma mimicking an intracranial malignant peripheral nerve sheath tumor

The authors present a case illustrating the importance of obtaining a biopsy of any facial skin lesions in a patient presenting with an intracranial tumor involving the facial or trigeminal nerve. Conventional malignant melanoma metastasizes to the brain frequently and does not usually pose diagnostic difficulties. Direct intracranial spread of cutaneous melanoma is rare. In our patient, desmoplastic melanoma with perineural spread to the Meckel cave mimicked a malignant peripheral nerve sheath tumor clinically, radiographically, and histologically.

Distinguishing neurofibroma from desmoplastic melanoma: the value of the CD34 fingerprint

We have observed 'fingerprint' immunopositivity in association with perineurioma and neurofibroma. A fingerprint consists of delicate, elongated areas of positive labeling that fall between collagen bundles, thereby creating a whorled configuration that is reminiscent of a human fingerprint. At present, the differential diagnosis between early desmoplastic melanoma and neurofibroma remains challenging in a subset of cases because of overlapping histopathological and immunohistochemical features. To assess whether fingerprint CD34 reactivity could be contributory in this context, we stained 50 desmoplastic melanomas and 50 neurofibromas with CD34. Fingerprint CD34 labeling was present in greater than 30% of the proliferation in 96% (n = 48) of neurofibromas and in only 4% (n = 2) of desmoplastic melanomas. Over two-thirds of the neurofibromas exhibited a CD34 fingerprint involving more than 60% of their surface area. In the two cases of desmoplastic melanoma that showed CD34 fingerprint positivity, the staining was patchy and involved less than 60% of the tumor. In partially staining neurofibromas, areas without a CD34 fingerprint tended to occur in central lobular areas. We conclude that CD34 fingerprint immunoreactivity is useful in distinguishing neurofibroma from early desmoplastic melanoma, especially if the fingerprint involves more than 60% of a tumor's cross-sectional area.

Perivascular epithelioid cell neoplasm of the uterine cervix: an unusual tumor in an unusual location

A 46-year-old woman presented for a second opinion regarding a 3–4 cm mass of the uterine cervix. A prior biopsy had been interpreted as a malignant melanoma of the cervix, resulting in a radical hysterectomy with bilateral salpingooophorectomy. This was to be followed by external beam irradiation and immunotherapy; however, given the rarity of this diagnosis, the patient sought a second opinion at our institution. Further review of the pathological material from the hysterectomy revealed a morphologically benign perivascular epithelioid cell neoplasm rather than a malignant melanoma. Close monitoring of the patient was recommended; she is currently diseasefree more than three years after her initial presentation.

Kita driven expression of oncogenic HRAS leads to early onset and highly penetrant melanoma in zebrafish

BACKGROUND

Melanoma is the most aggressive and lethal form of skin cancer. Because of the increasing incidence and high lethality of melanoma, animal models for continuously observing melanoma formation and progression as well as for testing pharmacological agents are needed.

METHODOLOGY AND PRINCIPAL FINDINGS

Using the combinatorial Gal4-UAS system, we have developed a zebrafish transgenic line that expresses oncogenic HRAS under the kita promoter. Already at 3 days transgenic kita-GFP-RAS larvae show a hyper-pigmentation phenotype as earliest evidence of abnormal melanocyte growth. By 2-4 weeks, masses of transformed melanocytes form in the tail stalk of the majority of kita-GFP-RAS transgenic fish. The adult tumors evident between 1-3 months of age faithfully reproduce the immunological, histological and molecular phenotypes of human melanoma, but on a condensed time-line. Furthermore, they show transplantability, dependence on mitfa expression and do not require additional mutations in tumor suppressors. In contrast to kita expressing melanocyte progenitors that efficiently develop melanoma, mitfa expressing progenitors in a second Gal4-driver line were 4 times less efficient in developing melanoma during the three months observation period.

CONCLUSIONS AND SIGNIFICANCE

This indicates that zebrafish kita promoter is a powerful tool for driving oncogene expression in the right cells and at the right level to induce early onset melanoma in the presence of tumor suppressors. Thus our zebrafish model provides a link between kita expressing melanocyte progenitors and melanoma and offers the advantage of a larval phenotype suitable for large scale drug and genetic modifier screens.

Analysis of steroid hormone effects on xenografted human NF1 tumor schwann cells

The neurofibroma, a common feature of neurofibromatosis type 1 (NF1), is a benign peripheral nerve sheath tumor that contains predominantly Schwann cells (SC). There are reports that neurofibroma growth may be affected by hormonal changes, particularly in puberty and pregnancy, suggesting an influence by steroid hormones. This study examined the effects of estrogen and progesterone on proliferation and apoptosis in a panel of NF1 tumor xenografts. SC-enriched cultures derived from three human NF1 tumor types (dermal neurofibroma, plexiform neurofibroma, and malignant peripheral nerve sheath tumor (MPNST)) were xenografted in sciatic nerves of ovariectomized scid /Nf1-/+ mice. At the same time, mice were implanted with time-release pellets for systemic delivery of progesterone, estrogen or placebo. Proliferation and apoptosis by the xenografted SC were examined two months after implantation, by Ki67 immunolabeling and TUNEL. Estrogen was found to increase the growth of all three MPNST xenografts. Progesterone was associated with increased growth in two of the three MPNSTs, yet decreased growth of the other. Of the four dermal neurofibroma xenografts tested, estrogen caused a statistically significant growth increase in one, and progesterone did in another. Of the four plexiform neurofibroma SC xenografts, estrogen and progesterone significantly decreased growth in one of the xenografts, but not the other three. No relationship of patient age or gender to steroid response was observed. These findings indicate that human NF1 Schwann cells derived from some tumors show increased proliferation or decreased apoptosis in response to particular steroid hormones in a mouse xenograft model. This suggests that anti-estrogen or anti-progesterone therapies may be worth considering for specific NF1 neurofibromas and MPNSTs.

Long-term treatment of Langerhans cell histiocytosis of the mandibular condyle with indomethacin

Langerhans cell histiocytosis (LCH) most commonly occurs as a localized solitary bone lesion and appears predominantly in pediatric patients. LCH is characterized by the proliferation and accumulation of Langerhans cells which may cause pain and adjacent soft-tissue swelling. This disease is of clinical importance to dental professionals because LCH commonly involves the oral and maxillofacial region and early symptoms can be manifested in the jaw and, when overlooked, may result in extensive destruction of the involved structures. Considering the fact that this is a relatively rare entity, close investigation of the cases that are encountered are warranted. Herein we report a case of LCH occurring in the left condyle of an 11-year-old boy that initially showed clinical symptoms mimicking an abscess of the temporomandibular joint. The clinical and radiographic features, differential diagnosis, treatment, and long-term follow-up of this patient with indomethacin are presented.

S100A2 in cancerogenesis: a friend or a foe?

Owing to the exceptional intracellular distribution and the heterogeneous expression pattern during transformation and metastasis in various tumors, the EF-hand calcium-binding protein S100A2 attracts increasing attention. Unlike the majority of S100 proteins, S100A2 expression is downregulated in many cancers and the loss in nuclear expression has been associated with poor prognosis. On the other hand, S100A2 is upregulated in some cancers. This mini review highlights the general characteristics of S100A2 and discusses recent findings on its putative functional implication as a suppressor or promoter in cancerogenesis.

[Isolated late-onset plexiform neurofibroma in the absence of neurofibromatosis]

BACKGROUND

Plexiform neurofibroma (NFP) is a benign nervous tumour typically involving the head and neck region due to the rich innervation of the latter. It is considered pathognomonic of neurofibromatosis type 1(NF1). This report describes an unusual case of neurofibroma and discusses its singular presentation, namely an isolated cutaneous tumour of late onset and with myofibroblastic histology.

CASE REPORT

A 85-year-old man presented swelling of the cutaneous part of the lower palpebral region which had been present for several months. The lesion was relapsing after repeated incomplete excisions and had grown slowly to become firm and suspect. It was decided to perform a large excision with a frontal rotation flap. Initial histological examinations performed on each excision suggested fibrosis and scarring, leading to diagnosis of fibrocytic change and post-surgical neuroma. The final histological analysis indicated diffuse plexiform neurofibroma with a myofibroblastic component. This was a solitary lesion in a patient without any stigmata or familial history of NF1.

DISCUSSION

This case is original in terms of its characteristics: a single cutaneous tumour of late onset in a patient with no stigmata of NF1 (in most cases of plexiform neurofibroma, NF1 is either multiple or else isolated at a mucous site). The histological findings for this tumour with a myofibroblastic component have never previously been described. Plexiform neurofibroma classically involves the head-and-neck region as in our case, with deep invasion of subcutaneous tissues making excision difficult and leading to frequent recurrence.

Patterns of GRP78 and MTJ1 expression in primary cutaneous malignant melanoma

Cell surface expression of glucose-regulated protein 78 (GRP78) occurs in several types of cancer; however, its role in the behavior of primary cutaneous melanoma is not well studied. The association of cell surface GRP78 with other proteins such as MTJ1 stimulates cell proliferation. In this study, we characterized the pattern of expression of GRP78 and MTJ1 in invasive primary cutaneous melanomas and analyzed the relationships between the pattern of expression and various clinicopathological parameters. We found two patterns of GRP78 expression in invasive primary cutaneous melanoma. One pattern showed a gradual fading of protein expression from superficial to deeper levels within the same tumor. The second pattern of expression showed a similar fading with an abrupt regaining of expression at the deep invasive edge of the melanoma. These two distinct patterns of GRP78 expression correlated with both patient survival and depth of tumor invasion. A moderate MTJ1 expression was found to be associated with decreased patient survival; however, no significant associations were observed between patterns of GRP78 and MTJ1 expression. Our study (1) describes two distinct patterns of GRP78 in invasive primary cutaneous melanoma, (2) inversely correlates regain of GRP78 expression with patient survival, and (3) suggests a modifying effect of MTJ1 on GRP78 in enhancing tumor aggressiveness.

Combination PPARgamma and RXR Agonist Treatment in Melanoma Cells: Functional Importance of S100A2

Nuclear hormone receptors, including RXR and PPARgamma, represent novel therapeutic targets in melanoma. We have previously shown that the DRO subline of the amelanotic melanoma A375 responds to rexinoid and thiazolidinedione (TZD) treatment in vitro and in vivo. We performed microarray analysis of A375(DRO) after TZD and combination rexinoid/TZD treatment in which the calcium binding protein S100A2 had increased expression after rexinoid or TZD treatment and a synergistic increase to combination treatment. Increased S100A2 expression is dependent on an intact PPARgamma receptor, but it is not sufficient to mediate the antiproliferative effects of rexinoid/TZD treatment. Over expression of S100A2 enhanced the effect of rexinoid and TZD treatment while inhibition of S100A2 expression attenuated the response to rexinoid/TZD treatment, suggesting that S100A2 is necessary for optimal response to RXR and PPARgamma activation by respective ligands. In summary, we have identified potential downstream mediators of rexinoid and TZD treatment in a poorly differentiated melanoma and found that alterations in S100A2 expression affect RXR and PPARgamma signaling in A375(DRO) cells. These studies provide insight into potential mechanisms of tumor response or resistance to these novel therapies.

Immunogenicity of HLA-A1-restricted peptides derived from S100A4 (metastasin 1) in melanoma patients

S100A4 (metastasin 1) belongs to the S100 family of Ca(2+) binding proteins. While not present in most differentiated adult tissues, S100A4 is upregulated in the micromilieu of tumors. It is primarily expressed by tumor-associated macrophages, fibroblasts, and tumor endothelial cells. Due to its strong induction in tumors S100A4 is a promising target for cancer immunotherapy. By reverse immunology, using epitope prediction programs, we identified 3 HLA-A1-restricted peptide epitopes (S100A4 A1-1, A1-2, and A1-3) which are subject to human T cell responses as detected in peripheral blood of melanoma patients by means of IFN-gamma ELISPOT and cytotoxicity assays. In addition, IFN-gamma responses to S100A4 A1-2 can not only be induced by stimulation of T cells with peptide-loaded DC but also by stimulation with S100A4 protein-loaded DC, indicating that this epitope is indeed generated by processing of the endogenously expressed protein. In addition, S100A4 A1-2 reactive T cells demonstrate lysis of HLA-A1(+) fibroblasts in comparison to HLA-A1(-) fibroblasts. In summary, this HLA-A1-restricted peptide epitope is a candidate for immunotherapeutical approaches targeting S100A4-expressing cells in the tumor stroma.