Type D personality is associated with poor QoL, three-year overall survival and mental health status among survivors of gastric cancer, even after adjustment of confounding background variables. The Type D personality group experienced increased levels of pain and fatigue compared to non-Type D patients. Type D personality might be a general vulnerability factor to screen for subgroups at risk of longer symptom duration and emergency admissions in clinical practice.

BackgroundMicroRNAs have been suggested to play a vital role in regulating carcinogenesis, tumor progression and invasion. MiR-335 is involved in suppressing metastasis and invasion in various human cancers. However, the mechanisms responsible for the aberrant expression of miR-335 in gastric cancer (GC) remain unknown.MethodsExpression of miR-335 in four GC cell lines and 231 GC tissues was determined by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). DNA methylation status in the CpG islands upstream of miR-335 in GC cell lines and tissues was determined by methylation-specific PCR and bisulfite sequence-PCR. The effects of the demethylating agent 5-aza-2′-deoxycytidine on cell proliferation, apoptosis, cell cycle, migration, and invasion were investigated in GC cell lines.ResultsCancer-specific methylation was detected in the upstream CpG-rich regions of miR-335, which dramatically silenced its transcriptional activity in GC cell lines and tissues. Low levels of miR-335 expression and high levels of miR-335 methylation in GC tissues were associated with poor clinical features and prognosis. Restoration of miR-335 expression in GC cells promoted cell apoptosis, inhibited tumor cell migration, invasion, and proliferation, and arrested the cell cycle at G0/G1 phase. Overexpression of miR-335 significantly reduced the activity of a luciferase reporter containing the 3′ untranslated region of V-crk avian sarcoma virus CT10 oncogene homolog-like (CRKL).ConclusionsMiR-335 functions as a tumor suppressor and may be silenced by promoter hypermethylation. It plays a role in inhibiting tumor cell migration, invasion, and proliferation, arresting the cell cycle at G0/G1 phase, and promoting apoptosis in GC cells through targeting CRKL.

Type D personality was associated with poor QoL and mental health status among survivors of rectal cancer, even after adjustment for confounding background variables. Type D personality might be a general vulnerability factor to screen for subgroups at risk for longer symptom duration and emergency admissions in clinical practice.