Epidermal growth factor receptor is a marker for syncytiotrophoblastic cells in testicular germ cell tumors

Targeted treatment approaches in refractory germ cell tumors

Germ cell tumors (GCTs) are the most common type of solid tumor amongst patients between 15 and 35 years of age. They are also one of the types of tumor with the highest cure rate, due to their high sensitivity to cisplatin based chemotherapy. Nonetheless, around 15-20% of metastatic patients will not have curative options after a relapse on the first and second line. This proves that new therapeutic options for these refractory GCTs patients need to be developed. This article offers a bibliographic review of all studies using targeted treatment or immunotherapy for refractory GCTs patients.

Differential Cytotoxicity of Different Sizes of Graphene Oxide Nanoparticles in Leydig (TM3) and Sertoli (TM4) Cells

Graphene oxide (GO) is an common nanomaterial and has attracted unlimited interest in academia and industry due to its physical, chemical, and biological properties, as well as for its tremendous potential in applications in various fields, including nanomedicine. Whereas studies have evaluated the size-dependent cytotoxicity of GO in cancer cells, there have been no studies on the biological behavior of ultra-small graphene nanosheets in germ cells. To investigate, for the first time, the cyto- and geno- toxic effects of different sizes of GO in two different cell types, Leydig (TM3) and Sertoli (TM4) cells, we synthesized different sized GO nanosheets with an average size of 100 and 20 nm by a modification of Hummers’ method, and characterized them by various analytical techniques. Cell viability and proliferation assays showed significant size- and dose-dependent toxicity with GO-20 and GO-100. Interestingly, GO-20 induced significant loss of cell viability and cell proliferation, higher levels of leakage of lactate dehydrogenase (LDH) and reactive oxygen species (ROS) generation compared to GO-100. Both GO-100 and GO-20 induced significant loss of mitochondrial membrane potential (MMP) in TM3 and TM4 cells, which is a critical factor for ROS generation. Furthermore, GO-100 and GO-20 caused oxidative damage to DNA by increasing the levels of 8-oxo-dG, which is formed by direct attack of ROS on DNA; GO-100 and GO-20 upregulate various genes responsible for DNA damage and apoptosis. We found that phosphorylation levels of EGFR/AKT signaling molecules, which are related to cell survival and apoptosis, were significantly altered after GO-100 and GO-20 exposure. Our results showed that GO-20 has more potent toxic effects than GO-100, and that the loss of MMP and apoptosis are the main toxicity responses to GO-100 and GO-20 treatments, which likely occur due to EGFR/AKT pathway regulation. Collectively, our results suggest that both GO-100 and GO-20 exhibit size-dependent germ cell toxicity in male somatic cells, particularly TM3 cells, which seem to be more sensitive compared to TM4, which strongly suggests that applications of GO in commercial products must be carefully evaluated.

IGF1R signalling in testicular germ cell tumour cells impacts on cell survival and acquired cisplatin resistance

Testicular germ cell tumours (TGCTs) are the most frequent malignancy and cause of death from solid tumours in the 20‐ to 40‐year age group. Although most cases show sensitivity to cis‐platinum‐based chemotherapy, this is associated with long‐term toxicities and chemo‐resistance. Roles for receptor tyrosine kinases other than KIT are largely unknown in TGCT. We therefore conducted a phosphoproteomic screen and identified the insulin growth factor receptor‐1 (IGF1R) as both highly expressed and activated in TGCT cell lines representing the nonseminomatous subtype. IGF1R was also frequently expressed in tumour samples from patients with nonseminomas. Functional analysis of cell line models showed that long‐term shRNA‐mediated IGF1R silencing leads to apoptosis and complete ablation of nonseminoma cells with active IGF1R signalling. Cell lines with high levels of IGF1R activity also showed reduced AKT signalling in response to decreased IGF1R expression as well as sensitivity to the small‐molecule IGF1R inhibitor NVP‐AEW541. These results were in contrast to those in the seminoma cell line TCAM2 that lacked IGF1R signalling via AKT and was one of the two cell lines least sensitive to the IGF1R inhibitor. The dependence on IGF1R activity in the majority of nonseminomas parallels the known role of IGF signalling in the proliferation, migration, and survival of primordial germ cells, the putative cell of origin for TGCT. Upregulation of IGF1R expression and signalling was also found to contribute to acquired cisplatin resistance in an in vitro nonseminoma model, providing a rationale for targeting IGF1R in cisplatin‐resistant disease. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Epidermal growth factor receptor and epididymis invasion as prognostic biomarkers in clinical stage I testicular germ cell tumours

Background

Inguinal orchiectomy is curative in 70–80% of clinical stage I testicular germ cell tumours (CS I TGCT). The identification of patients who are at low risk of relapse is critical to avoid unnecessary treatment. The aim of this study is to explore EGFR, hMLH-1/hMSH-2 and microsatellite instability (MSI) as potential prognostic factors of recurrence in CS I TGCT.

Methods

Fifty-six CS I TGCT patients who underwent inguinal orchiectomy were included in this study. We analysed the relationship between clinicopathological and molecular factors with survival. Analysis of hMLH1, hMSH2 and EGFR expression was carried out by immunohistochemistry. Methylation status of the hMLH1 promoter was determined by pyrosequencing analysis in selected cases. EGFR exons 19, 20, 21 were analysed by PCR labeled-fragments and MSI status was determined using standard Multiplex MSI assays.

Results

Classical pathological factors such as lymphovascular invasion, high percentage of embryonal carcinoma, rete testis invasion or tumour size ≥4 cm showed a significant relationship with a higher risk of relapse. Additionally, it was found that an epididymis invasion proved to be a significant independent poor prognostic factor of recurrence (p = 0.001). hMLH1 or hMSH2 expression showed no significant association with risk of relapse and no MSI was found. EGFR expression was observed in 30.4% of samples and its expression was associated with higher risk of relapse (HR 3.5; 95% CI 1.3–9.8; p = 0.016). None of the cases presented EGFR kinase domain mutations.

Conclusions

Epididymis invasion and EGFR expression, but not hMLH-1/hMSH-2 or MSI, could be potentially useful as new prognostic factors of recurrence for CS I TGCT.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1162-3) contains supplementary material, which is available to authorized users.

Effects of bleomycin and antioxidants on the fatty acid profile of testicular cancer cell membranes

Bleomycin is used in chemotherapy regimens for the treatment of patients having testicular germ-cell tumor (TGCT). There is no study in the literature investigating the effects of bleomycin on membrane lipid profile in testicular cancer cells. We investigated membrane fatty acid (FA) profiles isolated, derivatized and analyzed by gas chromatography of NTera-2 testicular cancer cells incubated with bleomycin (Bleo) for 24 h in the absence and presence of N-Acetyl-L-Cysteine (NAC) and curcumin (Cur) as commonly used antioxidant adjuvants. At the same time the MAPK pathway and EGFR levels were followed up. Bleomycin treatment increased significantly saturated fatty acids (SFA) of phospholipids at the expense of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Bleomycin also led to a significant increase in the trans lipid isomers of oleic and arachidonic acids due to its free radical producing effect. Incubation with bleomycin increased the p38 MAPK and JNK levels and downregulated EGFR pathway. Coincubation of bleomycin with NAC reversed effects caused by bleomycin. Our results highlight the important role of membrane fatty acid remodeling occurring during the use of bleomycin and its concurrent use with antioxidants which can adjuvate the cytotoxic effects of the chemotherapeutic agents.

ErbBs inhibition by lapatinib blocks tumor growth in an orthotopic model of human testicular germ cell tumor

In this work, we have analyzed the expression of different members of the ErbB family in human samples of testicular germ cell tumors (GCTs). We observed expression of ErbB1 or ErbB2 in different tumor subtypes, but we also found high expression of ErbB3 in all GCTs tested. This pattern of expression was maintained when primary tumors were orthotopically implanted in nude mice. We have chosen a choriocarcinoma model characterized by high levels of ErbB1, but also of ErbB2 and ErbB3, to assay the in vivo effect of ErbB inhibitors on tumoral growth. Our results showed a complete lack of effect (refractoriness) to the pure ErbB1 receptor inhibitors cetuximab and gefitinib. While these inhibitors blocked ErbB1 phosphorylation, ErbB2 phosphorylation was not affected, suggesting an ErbB1-independent activation of this receptor. To confirm the importance of ErbB2 activation, animals were treated with lapatinib, a dual ErbB1 and ErbB2 inhibitor. Lapatinib treatment caused a 50% inhibition in tumor growth, an effect correlated with a blockade of both ErbB1 and ErbB2 phosphorylation levels, and of downstream signaling pathways (Akt, ERKs and Stat3). ErbB2 activation could still occur due to the formation of ErbB2/ErbB3 heterodimers, and ErbB3 activation was completely inhibited by lapatinib. Finally, combined inhibition of ErbB1 (gefitinib) and ErbB3 activities (knockdown expression by shRNA) inhibited tumoral testicular cells proliferation in a similar way to lapatinib. Our results explain why lapatinib but not anti-ErbB1 agents might be effective for treatment of testicular GCT patients.

Genetics of gestational trophoblastic neoplasia: an update for the clinician

Gestational trophoblastic disease is a spectrum of disorders ranging from premalignant hydatidiform moles through to malignant invasive moles, choriocarcinoma and rare placental site trophoblastic tumor. The latter are often collectively referred to as gestational trophoblastic tumors or neoplasia (GTN). Although most women can expect to be cured of their disease, many interesting questions arise in the management of gestational trophoblastic disease. Current issues pertain to diagnosis of GTN, predicting progression from hydatidiform moles to GTN and the emergence of drug resistance in GTN. Our understanding of the genetics of GTN has helped us answer some of these questions but many remain unresolved. This article seeks to address recent advances in the genetics of GTN in relation to diagnosis, etiology, prognosis and treatment.

Protein overexpression and gene amplification of epidermal growth factor receptor in adult testicular germ cell tumors: potential role in tumor progression

Little is known about the pathologic significance of epidermal growth factor receptor (EGFR) expression in malignant testicular germ cell tumors (TGCTs) in adults. From the primary tumor sites of a cohort of 110 TGCT cases, we obtained 209 histologically distinct components: 53 intratubular germ cell neoplasia unclassified (IGCNU) lesions, 83 seminomas (66 pure-form seminomas and 17 seminoma components in the mixed-form with nonseminomatous TGCTs), 27 embryonal carcinomas, eight choriocarcinomas, 18 yolk sac tumors, and 20 immature teratomas. Samples were analyzed for expression of EGFR protein and EGFR gene amplification by immunohistochemistry and fluorescence in situ hybridization (FISH), respectively. Overexpression of the EGFR protein was detected in 28% of seminomas (27% in the pure-form and 29% in the mixed-form), 11% of embryonal carcinomas, 88% of choriocarcinomas, 44% of yolk sac tumors, and none of the IGCNU lesions or immature teratomas. A higher copy number (≥4 copies per cell) and amplification of the EGFR gene were detected in 20% and 10% of seminomas, 13% and 0% of embryonal carcinomas, 71% and 60% of choriocarcinomas, 15% and 8% of yolk sac tumors, and none of the IGCNU lesions or immature teratomas, respectively. Both higher copy number and amplification of the EGFR gene were positively correlated with immunohistochemical overexpression of EGFR protein (each P < 0.0001). These results suggest that overexpression of EGFR protein and increased copy number or amplification of the EGFR gene occur relatively frequently in primary TGCTs, and may play roles in the formation of invasive cancer and in the progression, especially morphological evolution, of tumors.

Her-2/neu expression in testicular cancer--a retrospective analysis in 57 cases

OBJECTIVES

To evaluate her-2/neu expression in testicular germ cell tumors (GCT).

METHODS

In patients with primary GCT her-2/neu expression was analyzed by immunohistochemistry (IHC). Furthermore, gene amplification was analyzed by chromogene in situ hybridization (CISH). For interpretation, the most recent Asco Guidelines were used.

RESULTS

The expression patterns were analyzed according to the histologic subtype. Immunohistochemical analysis demonstrated a weak (score 1) to moderate expression (score 2) in 1% of GCT; none of the GCT revealed a score 3 expression profile. By CISH analysis, we did not observe any gene amplification in the 57 GCT.

CONCLUSIONS

The analysis of her-2/neu expression in primary testicular cancer is of no therapeutic relevance. However, for the future we will explore the expression of her-2/neu in residual masses after chemotherapy to assess the role of targeted therapy in chemoresistant metastases.

Expression of EGFR, HER-2/neu and KIT in germ cell tumours

BACKGROUND

Germ cell tumours (GCTs) represent an extraordinarily chemosensitive malignancy. However, 20-30% of patients with advanced disease cannot be cured by currently available treatments. The role of tyrosine kinase receptors has been widely studied in other malignancies. Yet, limited information is available on GCTs.

METHODS

One hundred and nine paraffin-embedded GCTs in 84 patients were assessed by immunohistochemistry for epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER-2)/neu and KIT (CD117) expression. Univariate and multivariate analyses were performed to evaluate their role as predictive and/or prognostic factors.

RESULTS

EGFR and HER-2/neu staining was detected in 28% and 13% of tumours, respectively, predominantly in nonseminomatous GCTs. KIT protein was almost universally expressed in seminomas (97%), being virtually absent in choriocarcinoma and teratocarcinoma subtypes. EGFR expression showed inverse association with tumour response of borderline significance. With a median follow-up of 10.6 years, no significant association was observed between the expression of any of these markers and relapse-free or overall survival.

CONCLUSIONS

EGFR, HER-2/neu and KIT have differential patterns of expression in GCTs according to histological subtypes. The expression of these markers in our series had no prognostic or predictive significance.

Epidermal growth factor receptor protein expression and gene amplification in the chemorefractory metastatic embryonal carcinoma

Testicular cancer is the most common cancer in young male patients. The combination of cisplatin-based chemotherapy and surgery has resulted in high cure rates. However, a small percentage of patients have cancers that are refractory to chemotherapy; treatment options for these patients are limited, and their prognosis is generally poor. Further studies are needed to explore the molecular pathogenesis pathways and potential targets of therapy for this group of highly aggressive tumors. We analyzed 21 patients who presented with metastatic embryonal carcinoma, were treated with chemotherapy, and subsequently underwent retroperitoneal lymph node dissection. Immunostaining for epidermal growth factor receptor (EGFR) was performed on paraffin-embedded tissue sections containing tumor from these specimens, using the avidin-biotin-peroxidase method. EGFR gene amplification was performed by interphase fluorescence in situ hybridization (FISH). Immunohistochemically, 9 of 21 cases (43%) demonstrated positive EGFR staining; 12 of 21 cases (57%) had absent or very limited EGFR expression. FISH revealed EGFR amplification in 1 case (5%), polysomy in 15 of 21 cases (71%), and normal disomy pattern in 5 of 21 cases (24%). A significant correlation between EGFR protein expression level and its chromosome polysomy/amplification was established (P=0.02). Our study showed that EGFR protein is frequently expressed in a subset of patients with chemorefractory metastatic embryonal carcinoma. EGFR chromosomal polysomy/amplification may be one of the mechanisms that cause increased EGFR protein expression, and could potentially be used as indication for anti-EGFR therapy.

Oncofetal protein glypican-3 in testicular germ-cell tumor

The expression of an oncofetal protein, the glypican-3 (GPC3), was immunohistochemically evaluated in a wide variety of primary testicular germ-cell tumors (GCTs) in comparison with other markers, alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG)-beta, and OCT3/4. Eighty-nine cases of GCT including 22 cases of mixed GCT were evaluated with reference to each tumor component. GPC3 expression was observed in neoplastic cells of yolk-sac tumor (YST) (25/25), teratoma (2/10), components of syncytiotrophoblastic giant cells (STGCs) (10/14), and choriocarcinoma (1/3), but none in intratubular germ-cell neoplasias, unclassified type (0/33), seminomas (0/61), or embryonal carcinoma (0/19). All cases of YST showed diffuse labeling of neoplastic cells in cytoplasmic and membranous patterns, and the positive area of GPC3 was much larger than that of AFP. Glandular structures in teratomas showed GPC3 immunostaining as well as AFP. Although the number of GPC3-positive cells was smaller in STGC components and choriocarcinoma, there was no diffusion artifact in GPC3 immunostaining, as was frequently encountered in hCG-beta staining. Thus, GPC3 is a unique oncofetal protein, which is useful as an immunohistochemical marker for GCT differentiated to extraembryonic tissue, especially YST.

An autopsy case of primary mixed choriocarcinoma and mature teratoma located in the thymic region associated with elevated human chorionic gonadotropin levels and characteristic testicular changes

An autopsy case of a 19-year-old male Japanese student with a primary mixed choriocarcinoma and mature teratoma in the thymic region is reported. The patient died 7 days after he first noticed fever and dyspnea. On autopsy, an anterior mediastinal mass was found to be in contact with the thymic gland. The mass weighed 270 g and measured 12.5 cm x 10 cm x 5 cm. The left thoracic cavity contained 2200 ml bloody pleural effusion and 200 g coagula due to hemorrhage from the tumor. Metastasized choriocarcinoma was seen in both lungs and the liver. High serum levels of human chorionic gonadotropin (HCG, 1 634 000 mIU/ml) and a decreased weight of the testes (2.0 g each) with Leydig cell hyperplasia/hypertrophy and the seminiferous tubules with hyaline ghost tubules or Sertoli cell only tubules were seen; other male reproductive organs were histologically normal. Although the serum testosterone level was within the normal range (5.75 ng/ml), luteinizing hormone (LH, 0.1 mIU/ml) and follicle-stimulating hormone (FSH, 0.3 mIU/ml) levels were decreased. High serum levels of HCG and characteristic testicular changes are drscribed.