LAMC2 regulates proliferation, migration, and invasion mediated by the Pl3K/AKT/mTOR pathway in oral

Background

Oral squamous cell carcinoma (OSCC) is a common malignant tumor. Recently, Laminin Gamma 2 (LAMC2) has been shown to be abnormally expressed in OSCC; however, how LAMC2 signaling contributes to the occurrence and development of OSCC and the role of autophagy in OSCC has not been fully explored. This study aimed to analyze the role and mechanism of LAMC2 signaling in OSCC and the involvement of autophagy in OSCC.

Methods

To explore the mechanism by which LAMC2 is highly expressed in OSCC, we used small interfering RNA (siRNA) to knock down LAMC2 to further observe the changes in the signaling pathway. Furthermore, we used cell proliferation assays, Transwell invasion assays, and wound-healing assays to observe the changes in OSCC proliferation, invasion, and metastasis. RFP-LC3 was used to detect the level of autophagy intensity. A cell line-derived xenograft (CDX) model was used to detect the effect of LAMC2 on tumor growth in vivo.

Results

This study found that the level of autophagy was correlated with the biological behavior of OSCC. The downregulation of LAMC2 activated autophagy and inhibited OSCC proliferation, invasion, and metastasis via inhibiting the PI3K/AKT/mTOR pathway. Moreover, autophagy has a dual effect on OSCC, and the synergistic downregulation of LAMC2 and autophagy can inhibit OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway.

Conclusions

LAMC2 interacts with autophagy to regulate OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway. LAMC2 down-regulation can synergistically modulate autophagy to inhibit OSCC migration, invasion, and proliferation.

Effect of junctional adhesion molecule-2 expression on cell growth, invasion and migration in human colorectal cancer

The junctional adhesion molecule (JAMs) family belongs to the immunoglobulin subfamily involved in the formation of tight junctions (TJ) in both endothelial and epithelial cells. Aberrant expression of JAM-2 is associated with cancer progression but little work has been carried out in discovering how this affects changes in cell behaviour. The present study aimed to examine the expression of JAM-2 in human colon cancer specimens and cell lines and its role in the development of colon cancer. JAM-2 expression in human colon cancer specimens (normal, n=75; cancer, n=94) and cell lines was analysed using quantitative real-time PCR and conventional RT-PCR. Colon cancer cells were stably transfected with a mammalian expression vector to overexpress JAM-2-Flag. The effect on growth, adhesion and migration following overexpression of JAM-2 was then investigated using in vitro models. TJ function was assessed using a trans-epithelial resistance assay (TER, with an EVOM voltammeter). JAM-2 was lowly expressed in colon cancer cells such as RKO, HT115. JAM-2 overexpression in RKO cells (RKO-JAM-2) and HT115 cells (HT115-JAM-2) showed retarded adhesion (P<0.05). An in vivo tumour model showed that RKO-JAM-2 had significantly reduced growth (P<0.05), invasion (P<0.05) and migration (P<0.05) as well as in HT115-JAM-2, except on proliferation and migration. Expression of JAM-2 resulted in a significant increase in TER and decrease in permeability of polarized monolayers (P<0.05). Further analysis of JAM-2 transcript levels against clinical aspects demonstrated that the decreasing JAM-2 expression correlated to disease progression, metastasis and poor survival. Taken together, JAM-2 may function as a putative tumour suppressor in the progression and metastasis of colorectal cancer.

Vitamin D deficiency in anesthesia department caregivers at the end of winter

BACKGROUND

To test whether the vitamin D status of anesthesia department caregivers practicing at high Northern latitudes is compatible with current recommendations, the 25-hydroxyvitamin D (25(OH)D) levels of caregivers at hospitals in Iceland (64°08' N) and in Wisconsin (43°07' N) were compared at the end of winter.

METHODS

Anesthesia department faculty and resident physicians, non-physician anesthetists, and critical care nurses completed a questionnaire, and provided blood samples for analysis of 25(OH)D by reverse-phase high performance liquid chromatography.

RESULTS

One hundred and six participants in Iceland and 124 participants in Wisconsin were enrolled. No difference in mean serum 25(OH)D levels between Iceland [70.53 nmol/l, standard deviation (SD) 30.87 nmol/l] and Wisconsin (70.0 nmol/l, SD 30.0 nmol/l) was observed. In Iceland and Wisconsin, 25(OH)D levels below 25 nmol/l were observed in 4.7% and 4.0%, below 50 nmol/l in 34.9% and 25.0%, and below 75 nmol/l in 56.6% and 61.3% of caregivers, respectively.

CONCLUSIONS

25(OH)D levels below the 50 nmol/l (20 ng/ml) threshold recommended by the Institute of Medicine and the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and below the 75 nmol/l (30 ng/ml) threshold recommended by The Endocrine Society, are highly prevalent among anesthesia caregivers working at two Northern hospitals at the end of winter who may otherwise not meet criteria to be tested. Anesthesia and critical care providers may wish to determine their 25(OH)D levels and use effective, safe, and low cost supplementation to target a 25(OH)D level compatible with optimal health.

SPDEF functions as a colorectal tumor suppressor by inhibiting β-catenin activity

BACKGROUND & AIMS

Expression of the SAM pointed domain containing ETS transcription factor (SPDEF or prostate-derived ETS factor) is regulated by Atoh1 and is required for the differentiation of goblet and Paneth cells. SPDEF has been reported to suppress the development of breast, prostate, and colon tumors. We analyzed levels of SPDEF in colorectal tumor samples from patients and its tumor-suppressive functions in mouse models of colorectal cancer (CRC).

METHODS

We analyzed levels of SPDEF messenger RNA and protein in more than 500 human CRC samples and more than 80 nontumor controls. Spdef(-/-)and wild-type mice (controls) were either bred with Apc(Min/+) mice, or given azoxymethane (AOM) and dextran sodium sulfate (DSS), or 1,2-dimethylhydrazine and DSS, to induce colorectal tumors. Expression of Spdef also was induced transiently by administration of tetracycline to Spdef(dox-intestine) mice with established tumors, induced by the combination of AOM and DSS or by breeding with Apc(Min/+) mice. Colon tissues were collected and analyzed for tumor number, size, grade, and for cell proliferation and apoptosis. We also analyzed the effects of SPDEF expression in HCT116 and SW480 human CRC cells.

RESULTS

In colorectal tumors from patients, loss of SPDEF was observed in approximately 85% of tumors and correlated with progression from normal tissue, to adenoma, to adenocarcinoma. Spdef(-/-); Apc(Min/+) mice developed approximately 3-fold more colon tumors than Spdef(+/+); Apc(Min/+) mice. Likewise, Spdef(-/-) mice developed approximately 3-fold more colon tumors than Spdef(+/+) mice after administration of AOM and DSS. After administration of 1,2-dimethylhydrazine and DSS, invasive carcinomas were observed exclusively in Spdef(-/-) mice. Conversely, expression of SPDEF was sufficient to promote cell-cycle exit in cells of established adenomas from Spdef(dox-intestine); Apc(Min/+) mice and in Spdef(dox-intestine) mice after administration of AOM + DSS. SPDEF inhibited the expression of β-catenin-target genes in mouse colon tumors, and interacted with β-catenin to block its transcriptional activity in CRC cell lines, resulting in lower levels of cyclin D1 and c-MYC.

CONCLUSIONS

SPDEF is a colon tumor suppressor and a candidate therapeutic target for colon adenomas and adenocarcinoma.

Parecoxib mitigates spatial memory impairment induced by sevoflurane anesthesia in aged rats

BACKGROUND

Inflammation in brain plays a critical role in the pathogenesis of cognitive impairment. Anti-inflammatory therapy may thus constitute a novel approach for associated cognitive dysfunction. The present study investigated the effects of parecoxib in the prevention of cognitive impairments induced by sevoflurane in aged rats.

METHODS

Sixty-six aged rats were divided randomly into three groups: control group (n = 22, sham anesthesia), sevoflurane group (n = 22, received 2% sevoflurane for 5 h) and parecoxib group (n = 22, received intraperitoneal injections of 10 mg/kg parecoxib and then exposed to 2% sevoflurane for 5 h). Spatial learning performance was tested by Morris water maze. The expression of cyclooxygenase-2 protein and ultrastructure of synapse in hippocampus were measured.

RESULTS

Sevoflurane anesthesia impaired the spatial learning and memory in aged rats. Compared with sevoflurane group, parecoxib group showed shorter escape latency and more number of crossings over the previous platform area. Furthermore, parecoxib treatment also significantly prevented the synaptic changes induced by sevoflurane.

CONCLUSION

Parecoxib mitigates spatial memory impairment induced by sevoflurane anesthesia in aged rats. The synaptic morphometry change may be one of the mechanisms involved in learning and memory deficit.