Contrast-enhanced Ultrasonography Features for Diagnosing Pseudoprogression of Hepatocellular Carcinoma with Immunotherapy: A Case Report of the Response after Pseudoprogression.

A male patient in his 70s with recurrent hepatocellular carcinoma (HCC) after surgery received atezolizumab plus bevacizumab (Atezo+Bev) therapy. Initial computed tomography (CT) revealed tumor growth along with an increase in tumor markers, and contrast-enhanced ultrasonography (CEUS) showed multiple round avascular areas within the nodules with an appearance similar to a slice of Swiss cheese. Continuation of immunotherapy with consideration of the potential for pseudoprogression produced a dramatic response. Although it is difficult to distinguish between true progression and pseudoprogression, the Swiss cheese-like appearance on CEUS may be important for the early diagnosis of pseudoprogression.

Contrast-enhanced ultrasonography for the diagnosis of spontaneous necrosis of hepatocellular carcinoma: A report of 2 cases.

Spontaneous necrosis of hepatocellular carcinoma (HCC) is rare and difficult to diagnose preoperatively if it occurs before the definitive diagnosis of HCC; this is because spontaneous necrosis of HCC exhibits various patterns in imaging studies. We compared imaging and pathological findings, and examined the possibility of diagnosing spontaneous necrosis of HCC using contrast-enhanced ultrasonography (CEUS). We experienced 2 cases of spontaneous necrosis of HCC. In case 1, spontaneous necrosis occurred after HCC diagnosis, while in case 2 it occurred before the first admission. The tumor in case 2 contained internal nodules and outer fibrous tissue. CEUS revealed a vascular spot in the hypovascular area during the vascular phase and a complete defect during the Kupffer phase. These findings accorded with the pathological findings and may be important for diagnosing spontaneous necrosis of HCC.

Extracellular RNA transfer from non-malignant human cholangiocytes can promote cholangiocarcinoma growth.

Extracellular vesicles (EV) within the cellular secretome are emerging as modulators of pathological processes involved in tumor growth through their ability to transfer donor-derived RNA into recipient cells. While the effects of tumor and stromal cell EVs within the tumor microenvironment have been studied, less is known about the contributions of normal, nontransformed cells. We examined the impact of EVs within the cellular secretome from nonmalignant cells on transformed cell growth and behavior in cholangiocarcinoma cells. These effects were enhanced in the presence of the pro-fibrogenic mediator TGF-ß. We identified miR-195 as a TGF-ß responsive miRNA in normal cells that can be transferred via EV to tumor cells and regulate cell growth, invasion, and migration. The effects of miR-195 involve modulation of the epithelial-mesenchymal transition through direct effects on the transcription factor Snail. These studies provide in vitro and in vivo evidence for the impact of normal cellular secretome on transformed cell growth, show the importance of EV RNA transfer, and identify mechanisms of EV-mediated transfer of miRNA as a contributor to tumor development, which may provide new therapeutic opportunities for targeting human cholangiocarcinoma.

Extracellular vesicle-encapsulated miR-30e suppresses cholangiocarcinoma cell invasion and migration via inhibiting epithelial-mesenchymal transition.

Early-staged cholangiocarcinoma (CCA) is difficult to diagnose due to its high potential for invasion and metastasis. Epithelial-mesenchymal transition (EMT) is induced by transforming growth factor-ß (TGF-ß) in a process thought to be important for invasion and metastasis in several cancers, including CCA. Although microRNAs (miRNAs) have been implicated in the pathogenesis of several malignancies, their roles to CCA are not clearly understood. Some miRNAs were reported to be included in extracellular vesicles (EVs) and transferred from their donor cells to other cells, modulating recipient cell behaviors. In this study, the involvement and functional roles of EV-contained miRNAs during EMT in human CCA were determined. Expression profiling identified a subset of miRNAs that were reduced by TGF-ß in CCA cells. Among these, miR-30e was highly downregulated by TGF-ß and predicted to target Snail, which is an EMT-inducible transcription factor. MiR-30e overexpression suppressed cell invasion and migration via inhibiting EMT, whereas miR-30e inhibition promoted EMT, cell invasion and migration. Moreover, miR-30e was enriched in EVs derived from CCA cells after miR-30e overexpression, and miR-30e intercellular transfer through EVs suppressed EMT, cell invasion and migration in recipient CCA cells. Together, our results suggest that EV-mediated miR-30e transfer could inhibit EMT via directly targeting Snail, which subsequently suppresses CCA cell invasion and migration. These findings provide several new insights into regulatory mechanisms of tumor invasion and metastasis in human CCA.