Tuberous sclerosis complex presenting as primary intestinal lymphangiectasia: A case report.

BACKGROUND: Primary intestinal lymphangiectasia (PIL) is a rare congenital protein-losing enteropathy caused by dysplasia of the small intestinal lymphatics. The cause of the disease is unknown. Through a literature review, we found that PIL and tuberous sclerosis complex (TSC) have some common symptoms and molecular pathways. CASE SUMMARY: Here, we present the case of a patient with a three-year history of primary intestinal lymphangiectasia. The patient most recently visited the hospital with abdominal distension and swelling of the left leg. His mother told us that she was diagnosed with TSC one year previously, which alerted us because the patient had multiple regions of pigmentation. To evaluate the condition of the child and make a definite diagnosis, multiple imaging examinations were performed, as was TSC gene analysis. The results met the diagnostic criteria for TSC. The patient was discharged after symptomatic treatment. Through a review of the literature, it can be seen that changes at the molecular gene level of TSC can lead to abnormal lymphatic vessels. CONCLUSION: In summary, when patients with hypomelanotic macules or enamel hypoplasia are diagnosed with PIL, TSC gene screening may be important for further diagnosis.

Arsenic trioxide induces autophagic degradation of the FLT3-ITD mutated protein in FLT3-ITD acute myeloid leukemia cells.

The prognosis of acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations is poor. Some studies, including our previous study, have indicated that arsenic trioxide (ATO) exhibited significant anti-carcinogenic activity in FLT3-ITD AML cells and explored the possibility of targeting the FLT3-ITD protein for degradation as a therapy. Autophagy is a critical mechanism of the anti-leukemic effects of ATO. In this study, we explored the therapeutic efficacy of ATO treatment in a mouse model bearing FLT3-ITD AML and found that ATO significantly reduced the leukemic burden in bone marrow and spleen. We also found that autophagy was responsible for, at least in part, the degradation of the FLT3-ITD protein by ATO. After ATO treatment, MV4-11 cells showed complete autophagic flux. The autophagy inhibitor bafilomycin A or down-regulation of the key autophagy genes Atg5 and Atg7 reversed the FLT3 degradation induced by ATO. We also found that p62/SQSTM1 delivered FLT3-ITD proteins to the lysosome, where they were subsequently degraded. These results indicate that ATO can induce autophagic degradation of the FLT3-ITD mutated protein in FLT3-ITD AML.

Arsenic trioxide and all-trans-retinoic acid selectively exert synergistic cytotoxicity against FLT3-ITD AML cells via co-inhibition of FLT3 signaling pathways.

FLT3-ITD mutations occur in approximately 30% of acute myeloid leukemia (AML) and are associated with a poor outcome. Currently available FLT3 inhibitors have in vitro but limited clinical activity in FLT3-ITD AML. Reports have shown that an arsenic trioxide (ATO)/all-trans-retinoic acid (ATRA) combination improves prognosis in acute promyelocytic leukemia, especially with FLT3-ITD, and ATO or ATRA alone enhances apoptosis in FLT3-ITD AML cells treated with FLT3 inhibitors, providing a rationale to investigate the role of ATO/ATRA in FLT3-ITD AML. Here, we demonstrate that an ATO/ATRA combination selectively exerts synergistic cytotoxicity against FLT3-ITD AML cell lines (MV4;11/MOLM-13). The signaling pathways affected by ATO/ATRA include FLT3/STAT5/MYC, FLT3/STAT5/E2F1, FLT3/ERK/ATF5 and FLT3/AKT/ATF5.ATF5 may function as an oncogene in FLT3-ITD AML. Our findings provide experimental evidence that supports further exploration of ATO/ATRA in FLT3-ITD AML in vivo and warrants a clinical evaluation of regimens comprising an ATO/ATRA combination.