Clear Cell Adenocarcinoma of the Ureter Similar to Clear Cell Renal Cell Carcinoma Histology

A 70-year-old woman was referred to our hospital with gross hematuria and diagnosed with right invasive ureteral cancer and bladder urothelial carcinoma in situ. Intravesical BCG therapy and neoadjuvant chemotherapy with carboplatin and gemcitabine were performed at the same time. Subsequently, laparoscopic right nephroureterectomy was performed. Urothelial carcinoma in situ persisted; however, most of the tumor was clear cell carcinoma. The clear cell carcinoma lesion had clear cytoplasm with round nuclei and visible nucleoli in an insular arrangement as is the case with clear cell renal cell carcinoma. No transitional lesion between clear cell adenocarcinoma and urothelial carcinoma was presented. The clear cell carcinoma lesion was GATA3 negative and HNF4α positive; however, the urothelial cancer lesion was GATA3 positive and HNF4α negative. Clear cell carcinoma was diagnosed as clear cell adenocarcinoma similar to clear cell renal cell carcinoma histology.

The PI3K/AKT Pathway Is Activated by HGF in NT2D1 Non-Seminoma Cells and Has a Role in the Modulation of Their Malignant Behavior

Overactivation of the c-MET/HGF system is a feature of many cancers. We previously reported that type II testicular germ cell tumor (TGCT) cells express the c-MET receptor, forming non-seminomatous lesions that are more positive compared with seminomatous ones. Notably, we also demonstrated that NT2D1 non-seminomatous cells (derived from an embryonal carcinoma lesion) increase their proliferation, migration, and invasion in response to HGF. Herein, we report that HGF immunoreactivity is more evident in the microenvironment of embryonal carcinoma biopsies with respect to seminomatous ones, indicating a tumor-dependent modulation of the testicular niche. PI3K/AKT is one of the signaling pathways triggered by HGF through the c-MET activation cascade. Herein, we demonstrated that phospho-AKT increases in NT2D1 cells after HGF stimulation. Moreover, we found that this pathway is involved in HGF-dependent NT2D1 cell proliferation, migration, and invasion, since the co-administration of the PI3K inhibitor LY294002 together with HGF abrogates these responses. Notably, the inhibition of endogenous PI3K affects collective cell migration but does not influence proliferation or chemotactic activity. Surprisingly, LY294002 administered without the co-administration of HGF increases cell invasion at levels comparable to the HGF-administered samples. This paradoxical result highlights the role of the testicular microenvironment in the modulation of cellular responses and stimulates the study of the testicular secretome in cancer lesions.