SATB1 is a potential therapeutic target in intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignant tumor of the liver with a poor prognosis. Upregulation of special AT-rich sequence-binding protein 1 (SATB1) promotes tumor progression. However, little is known about the role of SATB1 in ICC tumorigenesis. METHODS: We firstly investigated the expression of SATB1 in 88 cases of ICC by immunohistochemistry (IHC), QRT-PCR, and western blot. Meanwhile, we constructed stably knockdown (shRNA) of SATB1 in ICC cell lines to evaluate the effects of SATB1 on the ability of cell proliferation and invasion by MTT and transwell invasion assay. RESULTS: Our result showed that SATB1 was overexpressed in ICC tissues samples. Knockdown of SATB1 could inhibit ICC cell proliferation, and suppress ICC cell invasion of ICC cell lines. In addition, the depletion of SATB1 expression suppressed the MYC levels in vitro. CONCLUSIONS: Our results highlight the significance of SATB1 in ICC and suggest that SATB1 could be a promising therapy target and a potential biomarker for prognosis in ICC patients.

The value of SATB2 in the differential diagnosis of intestinal-type mucinous tumors of the ovary: primary vs metastatic.

Primary mucinous adenocarcinomas of the ovary are a diagnostic challenge because their histologic and immunohistochemical features usually overlap with metastatic tumors. SATB2 is a recently identified protein with restricted expression in the glandular cells lining the lower gastrointestinal tract. The aim of this study is to examine the differential expression of SATB2 in primary and metastatic tumors of the ovary. Mucinous ovarian tumors of intestinal type were retrieved from the pathology files of the Instituto Nacional de Cancerología de México. A double reading of the hematoxylin and eosin-stained slides was performed to confirm the diagnosis, and a detailed review of the clinical chart was performed to define the primary origin of the tumor (ovarian vs metastatic). Immunohistochemical staining for CK20, CDX2, and SATB2 was performed and evaluated by 2 gynecopathologists. A total of 106 mucinous tumors were identified, 26 of which were considered to be metastatic, and 80 of which were primary ovarian tumors. All of the primary tumors that were not associated with cystic teratomas were negative for SATB2, and the 4 that were associated with a teratoma were positive for SATB2. All 20 of the metastatic tumors of the colon and appendix were positive for CK20, and 4 were positive for CK7. In addition, all 20 of these tumors were positive for SATB2, and 19 were positive for CDX2. SATB2 appears to be a useful marker for the diagnosis of primary vs metastatic mucinous intestinal-type neoplasms and is highly sensitive in detecting lower gastrointestinal tract metastasis.

Expression and significance of SATB1 in the development of breast cancer.

Special AT-rich sequence binding protein 1 (SATB1) is a recently discovered gene regulator that can promote the growth and metastasis of breast cancer. However, its expression in different stages of breast cancer development have not been examined. We explored the role of SATB1 in the development of breast cancer by detecting SATB1 expression levels in different stages of breast cancer. SATB1 expression was determined using an immunohistochemical streptavidin peroxidase method; the relationship between clinicopathological features of breast cancer and SATB1 expression was analyzed using the X(2) test. Positive rates of SATB1 protein in normal breast tissue, normal breast ductal hyperplasia tissue, precancerous lesions of breast cancer, non-invasive cancer, early invasive carcinoma, and invasive breast cancer tissue were, respectively, 6.25 (2/32), 6.4 (3/47), 20.4 (10/49), 45.0 (9/20), 52.9 (9/17), and 76.6% (72/94). SATB1 in the latter 3 groups was significantly higher than in the first 3 groups (P < 0.05). The positive rate of SATB1 protein in invasive non-special types of breast cancer (88.5%, 54/61) was significantly higher than in the special type of invasive breast cancer (54.5%, 18/33) and early invasive breast cancer (52.9%, 9/17) (P < 0.05). SATB1 protein expression in breast cancer with lymph node metastasis was generally increased, and the difference was statistically significant (P < 0.05). SATB1 protein expression showed an increasing trend in different stages of breast cancer development. Overexpression indicated poor prognosis.

Overexpression of miR-21-5p as a predictive marker for complete tumor regression to neoadjuvant chemoradiotherapy in rectal cancer patients.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) followed by radical surgery is the preferred treatment strategy for locally advanced rectal cancer. However, complete tumor regression is observed in a significant proportion of patients after nCRT, making them ideal candidates for alternative treatment strategies to this considerably morbid procedure. Identification of such patients based on clinical findings (complete clinical response - cCR) is difficult mainly because it relies on subjective clinical and imaging studies. Our goal was to identify biomarkers capable of predicting complete response to nCRT. METHODS: We analyzed miRNA expression profile using deep sequencing in rectal tumor biopsies prior to nCRT. Differential expression was investigated by EdgeR for a training (n = 27) and a validation (n = 16) set of patients to identify miRNAs associated with treatment response (complete vs. incomplete). In vitro experiments with two cancer cell lines were also performed in order to evaluate the possible role of miRNAs on response to nCRT. RESULTS: We found 4 miRNAs differentially expressed between complete and incomplete responders to nCRT. In addition, validation was performed using an independent group of patients and miR-21-5p was confirmed as being overexpressed in complete responders. Overall sensitivity and specificity of miR-21-5p expression in predicting complete response to nCRT was 78% and 86% respectively. Interestingly, in a subset of patients with cCR followed by early local recurrence, the expression level of miR-21-5p was considerably low, similarly to incomplete responders. We also found SATB1, a miR-21-5p target gene and known multidrug resistance gene, whose expression was inversely correlated with miR-21-5p expression. Finally, we performed functional experiments and showed that miR-21-5p and SATB1 may be directly involved with poor response to nCRT in rectal cancer patients. CONCLUSIONS: This study suggests miR-21-5p as a promising predictive biomarker, which should aid in the selection of patients with cCR to nCRT that potentially could be spared from radical surgery.