G-4 inhibits triple negative breast cancer by inducing cell apoptosis and promoting LCN2-dependent ferroptosis.

Compound G-4 is a derivate of cyclin-dependent kinase inhibitor Rocovitine and showed strong sensitivity to triple negative breast cancer (TNBC) cells. In this study, the antitumor activity, mechanism and possible targets of G-4 in TNBC were investigated. Flow cytometry and immunoblotting showed that G-4 not only arrested the S phase of the cell cycle, but also induced apoptosis in TNBC cells via the mitochondrial pathway through inhibiting epidermal growth factor receptor (EGFR), AKT and MAPK pathways. In addition, G-4 induced the iron-mutagenesis process in TNBC cells and down-regulated differentially expressed gene lipid carrier protein 2 (LCN2) by RNA-seq. Moreover, G-4 elevated levels of cytosolic reactive oxygen species (ROS), lipid ROS, Fe and malondialdehyde (MDA), but decreased levels of superoxide dismutase (SOD) and glutathione (GSH), consistent with the effects of iron-mutagenic agonists Erastin and RSL3, which were inhibited by the iron inhibitor ferrostatin-1 (Fer-1). Furthermore, a LCN2 knockdown cell model was established by siRNA transfection, the IC50 of G-4 was increased nearly 100-fold, accompanied by a trend of no ferroptosis characteristic index. The results indicated that G-4 suppressed the malignant phenotype of TNBC, induced apoptosis by inhibiting EGFR pathway and promoted LCN2-dependent ferroptosis.

Synthesis and mechanism of action of new purine derivatives against triple negative breast cancer.

Triple negative breast cancer (TNBC) is considered to be the most difficult subtype of breast cancer to treat because of its extremely prone to metastasis and the lack of targeted therapy drugs. New purine derivatives were synthesized and evaluated in a series of kinases and cell lines. The most active compounds 3g and 3j were selected based on their antiproliferative activities, then their pharmaceutical activity and mechanism in MDA-MB-231 cells were analyzed. The results in vitro indicated that compounds 3g and 3j can induce MDA-MB-231 cells apoptosis, and inhibit its migration and angiogenesis through influencing protein expression such as Bcl-2, Bax, Bcl-xl, P38, MMP2, MMP9, AKT and EGFR. In vivo results indicate that compounds 3g and 3j can inhibit tumor growth and metastasis and reduce the expression of Ki67 and CD31 protein in TNBC xenograft models. These findings not only broaden our understanding of the anti-TNBC effects and mechanisms of compounds 3g and 3j, but also provide new ideas and reference directions for the treatment of TNBC.

Role of lncRNA LINC01194 in hepatocellular carcinoma via the miR-655-3p/SMAD family member 5 axis.

Long non-coding RNAs (lncRNAs) are involved in developing hepatocellular carcinoma (HCC). The present study explored the role of lncRNA LINC01194, which is upregulated in HCC tissues and might be a vital regulator in HCC progression. Levels of LINC01194, microRNA (miR)-655-3p, and SMAD family member 5 (SMAD5) were assessed using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The bioactivity of Huh-7 cells was assessed using cell counting kit-8 and transwell assays and flow cytometry. Western blotting was conducted to measure the expression of invasion- and apoptosis-related proteins. The relationships between lncRNA LINC01194 and miR-655-3p, and miR-655-3p and SMAD5 were predicted using StarBase and TargetScan, and further verified using a dual-luciferase reporter assay. LINC01194 was overexpressed in HCC cells and in clinical samples. ILINC01194 silencing suppressed proliferation and migration; however, it promoted apoptosis in HCC cell lines. We also confirmed that miR-655-3p could bind to LINC01194, and miR-655-3p was downregulated in HCC. The upregulation of miR-655-3p suppressed HCC cell invasion and migration, and enhanced the number of apoptotic cells. SMAD5, which was overexpressed in HCC cell lines, was directly targeted by miR-655-3p. Therefore, LINC01194 promoted HCC development by decreasing miR-655-3p expression and may serve as a promising therapeutic target for HCC patients.

[Comparative study of CT versus gross pathology in rabbit VX2 colorectal cancer model].

OBJECTIVE: To establish rabbit VX2 colorectal cancer(CRC) model and to compare CT images with gross pathology in order to offer help for TNM staging in patients with CRC. METHODS: VX2 tumor pieces were implanted into colonic wall in 9 New Zealand white rabbits and rectal wall in 2 New Zealand white rabbits. Four weeks after inoculation, Ultravist(370 mg/ml) was injected through ear marginal vein with high pressure injector for stage 3 scanning of chest, abdomen and pelvis, and enhanced CT (collimation 0.5 mm mm × 320, pitch factor 0.828, bulb rotation speed 0.5 s/cycle, 120 kV, automatic ma, range 80 to 100 mAs) was performed to determine the presence of CRC or metastasis once a week for 4-6 weeks. Once inoculated CRC or metastases occurred or 6 weeks after implantation, the rabbits were sacrificed regardless of the presence or absence of CRC or metastasis on the CT images. One rabbit was used for gross anatomy observation. Others were placed in wood boxes with -80centi-degree for 24 hours, then samples of 3 mm thickness were cut using a motorized saw to make macropathology. Each cutting surface of the specimens was photographed in serial number. If certain or suspected lesions were found on the slices, such part was labeled and then placed in 10% phosphate-buffered formaldehyde numbered box for subsequent pathological examination. CT image postprocessing was performed referring to the gross slice specimens and all findings were compared with the pathological reports. RESULTS: Among 11 rabbits, tumor was successfully established in 8 rabbits. Pathology showed that single lung metastasis (7 to 10 mm) was found in 2 rabbits and liver metastasis (9 mm) in 1 rabbit. Number of lymph node located around the inoculated tumor was 22 and that around mesenteric vessels was 13 with diameter of 2 to 16 mm. Among these 35 lymph nodes from 8 successful rabbits, 9 nodes were positive, including 7 around inoculated tumor and 2 around mesenteric vessels. CT identified above 8 primary inoculated tumors, 2 lung metastatic lesions and 1 liver metastatic lesion, with detection rate of 100%. For the detection of lymph node in CT, 27 nodes were identified in the pericolorectal region (17 nodes) and perimesenteric vessels (10 nodes), in which 6 were positive metastasis (ring-shaped enrichment and central low density necrosis), resulting in a detection rate of 77.1%(27/35 nodes), and positive detection rate of 66.7% (6/9 nodes), respectively. CONCLUSION: Living rabbit CT-gross pathological slice(3 mm-cut) of VX2 CRC model can be applied in image evaluation of small metastatic lesion.

Caveolin-1, E-cadherin and ß-catenin in Gastric Carcinoma, Precancerous Tissues and Chronic Non-atrophic Gastritis.

OBJECTIVE: To investigate the expressions of caveolin-1, E-cadherin and ß-catenin in gastric carcinoma, precancerous gastric and chronic non-atrophic gastritis tissues, and evaluate the correlation of these expressions with the development of gastric cancer. METHODS: The expressions of caveolin-1, E-cadherin and ß-catenin were detected by biotin-streptavidin- peroxidase (SP) immunohistochemistry on 58 gastric cancer tissues, 40 precancerous gastric tissues and 42 chronic non-atrophic gastritis tissues. The correlation between the expressions of caveolin-1, E-cadherin and ß-catenin, and the clinicopathologic parameters of gastric cancer was analyzed retrospectively. RESULTS: The positive rates of caveolin-1 and E-cadherin expressions in gastric carcinoma were significantly lower than precancerous gastric and chronic non-atrophic gastritis tissues (P<0.01). An abnormal rate of ß-catenin expression in gastric carcinoma was higher than precancerous gastric and chronic non-atrophic gastritis tissues (P<0.01). Moreover, low expressions of caveolin-1, E-cadherin and ß-catenin correlated with tumor size, depth of invasion, lymph node metastasis and TNM stage (P<0.05). The positive rates of caveolin-1 and E-cadherin expressions decreased (P<0.01), while an abnormal rate of ß-catenin expression increased inversely, with the degree of atypical hyperplasia (P<0.01). Caveolin-1 expression correlated positively with E-cadherin (r=0.41, P<0.05). Caveolin-1 (r=-0.36, P<0.05) and E-cadherin (r=-0.45, P<0.05) expressions negatively correlated with abnormal ß-catenin expression. CONCLUSION: These results suggested that dysregulated expressions of caveolin-1, E-cadherin and ß-catenin correlated with the development of gastric cancer and its biological behavior.