Expression of T helper 1-associated lncRNAs in breast cancer

Interferon gamma (IFN-gamma)-associated genes participate in the pathobiology of cancer and response of patients to immunotherapeutic modalities. This cytokine is regarded as a hallmark of T helper 1 type responses. In the current study, we estimated expression of this gene and a number of genes/ long non-coding RNAs (IFNG.AS001 and IFNG.AS003, AC007278.2 and AC007278.3 and IL18R1) which are encoded from proximal genomic regions to IFNG in a larger cohort of Iranian patients with breast cancer. Both IFNG.AS001 and IFNG.AS003 were up-regulated in breast cancer tissues compared with nearby non-cancerous tissues (Ratios of Mean Expressions = 5.62 and 5.88, P values = 1.28E-03 and 1.47E-03, respectively). Finally, IL18R1 was over-expressed in breast cancer tissues compared with nearby non-cancerous tissues (Ratio of Mean Expressions = 9.43, P values = 3.14E-03). Expression of AC007278.3 was associated with breast feeding duration (P value = 2.65E-02). Positive significant correlations were detected between expression levels of all genes in both sets of samples. The most robust correlation in the nearby non-cancerous tissues was detected between IFNG-AS003 and AC007278.2 (r = 088, P value = 5.19E-23). In the tumoral tissues, the strongest correlation was found between IFNG-AS001 and IL18R1 (r = 0.86, P value = 3.79E-15). AC007278.3 had the best diagnostic power among the assessed genes (AUC = 0.82). Both AC007278.2 and AC007278.3 were reported to be specific markers for differentiation of tumor tissues from nearby non-cancerous tissues. Combination of expression levels of genes increased specificity, sensitivity and AUC values to 0.97, 0.89 and 0.95, respectively. The current study accentuates the role of IFNG-associated genes in the pathogenesis of breast cancer.