Autophagy-related Proteins as a Prognostic Factor of Patients With Colorectal Cancer.

OBJECTIVES: Autophagy plays a dual role in tumorigenesis. In the initial stages, it promotes cell survival and suppresses carcinogenesis, whereas in cancer development, it induces cancer cell survival. In this study, we investigate the role of autophagy as a protective or tumor suppressor mechanism in colorectal cancer (CRC) cell lines and evaluate its role as a potential biomarker in human tumor samples. MATERIALS AND METHODS: The data of 68 patients with CRC treated at our Department from January 1 to December 31, 2016 were analyzed. Immunohistochemistry evaluation of p62, LC3B, Beclin-1, and Rab-7 in formalin-fixed paraffin-embedded tissue samples was performed and their expression was correlated with clinicopathologic characteristics, mutation status, and therapeutic approach. The χ was used to test an association among categorical variables. Survival curves were estimated using the Kaplan-Meier method and differences were assessed using the log-rank test. Colo-205, HT29, SW-480, and Caco-2 cell lines were also used so as to test the autophagy markers with oxaliplatin, irinotecan, hydroxychloroquine, and 3-methyladenine. RESULTS: Overexpression of Beclin-1 is associated with poor survival (P=0.001) in patients with CRC treated with chemotherapy, irrespective of the stage and mutational status. Rab-7 is also correlated with progression-free survival (PFS) (P=0.088). Oxaliplatin (10 and 20 µΜ) and irinotecan (10 and 20 µΜ) inhibit autophagy in microsatellite stable (MSS) CRC cell lines. The inhibition of autophagy in MSS CRC cell lines after treatment with oxaliplatin and irinotecan is further identified through monodancylcadaverine staining. Moreover, inhibition of autophagy with molecules such as hydroxychloroquine (20 µΜ) and 3-methyladenine (5 mM) was identified by the accumulation of p62 and LC3B. CONCLUSIONS: Beclin-1 is an independent prognostic factor of overall survival and PFS. Also, Rab-7 is identified as an independent prognostic factor of PFS. Besides, several chemotherapeutic drugs such as oxaliplatin and irinotecan inhibit autophagy in MSS CRC cell lines in a similar way like hydroxychloroquine and 3-methyladenine. Thus, in MSS patients who develop chemoresistance, a combination of other therapies that include an autophagy inhibitor could be more beneficial. Further clinical trials are needed to investigate these therapeutic strategies.

The Interplay of Autophagy and Tumor Microenvironment in Colorectal Cancer-Ways of Enhancing Immunotherapy Action.

Autophagy as a primary homeostatic and catabolic process is responsible for the degradation and recycling of proteins and cellular components. The mechanism of autophagy has a crucial role in several cellular functions and its dysregulation is associated with tumorigenesis, tumor-stroma interactions, and resistance to cancer therapy. A growing body of evidence suggests that autophagy is also a key regulator of the tumor microenvironment and cellular immune response in different types of cancer, including colorectal cancer (CRC). Furthermore, autophagy is responsible for initiating the immune response especially when it precedes cell death. However, the role of autophagy in CRC and the tumor microenvironment remains controversial. In this review, we identify the role of autophagy in tumor microenvironment regulation and the specific mechanism by which autophagy is implicated in immune responses during CRC tumorigenesis and the context of anticancer therapy.

A rare case of a splenic hamartoma in a patient with a huge palpable abdominal mass: a case report.

INTRODUCTION: Splenic hamartoma is a primary benign tumor of the spleen, which is often found incidentally. Splenic hamartomas are very rare, with approximately 150 cases documented in the literature to date. They represent benign vascular proliferation. Histological findings consist of disorganized stroma and vascular channels of varying width, with or without lymphoid follicles. CASE PRESENTATION: We present the case of a 39-year-old Greek woman, with no significant medical history, who was diagnosed incidentally with an enormous splenic hamartoma on computed tomography, finally confirmed by surgery and histopathology. Hamartomas are benign lesions, and it is important to differentiate them from malignancy. CONCLUSION: Hamartoma represents a rare vascular entity characterized by a cluster of differentiation 8-positive immunophenotype. It is usually asymptomatic but large hamartomas may present with symptoms such as hemopoetic disorders, which resolve after splenectomy. It is important for radiologists to be able to differentiate splenic hamartoma from malignant entities.