Breast cancer (BC) is an important cause of female cancer‐related death. It has recently been demonstrated that metabolic disorders including lipid metabolism are a hallmark of cancer cells. Lipin‐1 is an enzyme that displays phosphatidate phosphatase activity and regulates the rate‐limiting step in the pathway of triglycerides and phospholipids synthesis. The objective of this study was to evaluate lipin‐1 expression, its prognostic significance, and its correlation with p53 tumor suppressor in patients with BC. In this study, 55 pairs of fresh samples of BC and adjacent noncancerous tissue were used to analyze lipin‐1, using quantitative real‐time polymerase chain reaction and immunohistochemistry (IHC) staining. The expression of other clinicopathological variables and p53 was also examined using IHC technique. The cell migration was studied in MCF‐7 and MDA‐MB231 cells following the inhibition of lipin‐1 by propranolol. Our results show that the relative expression of lipin‐1 messenger RNA was significantly higher in BC tissues compared with the adjacent normal tissue and its inhibition reduced cell migration in cancer cells. This upregulation was negatively correlated with histological grade of tumor and p53 status (p = .001 and p = .034) respectively and positively correlated with the tumor size (p = .006). Our results also seem to indicate that the high lipin‐1 expression is related to a good prognosis in patients with BC. The expression of lipin‐1 may be considered as a novel independent prognostic factor. The inhibition of lipin‐1 may also have therapeutic significance for patients with BC. The correlation between lipin‐1 and p53 confirms the role of p53 in the regulation of lipid metabolism in cancer cells.

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One of the most common somatic mutations in breast cancer is found in PIK3CA with a prevalence rate of 18-45%. Different variants of this gene are considered as resistance markers for treatment with HER2-targeted medicines. Conventional molecular methods such as Sanger sequencing are not able to detect mutations with low abundance in a mixture of wild-type DNA, especially in the early stages of cancer development. In this study, two methods of co-amplification at lower denaturation temperature PCR (COLD-PCR) and high-resolution melting (HRM) were combined for detection of mutations in exon 9 of PIK3CA; DNA, therefore, was extracted from MCF-7 and BT-474 as mutant and wild-type cell lines respectively. Thereafter, serial dilutions of extracted DNA were used to determine sensitivity of full-COLD PCR/HRM in comparison with conventional PCR sequencing as the gold standard method. Cell line experiments resulted in almost 30 fold increase in sensitivity by use of full-COLD PCR/HRM. In addition, 40 patients with primary breast cancer were investigated with the mentioned methods. As a result of this part of study, four mutations were detected by conventional PCR sequencing including E542K and E545K mutations in three and one samples respectively. Whereas, full-COLD PCR/HRM was able to detect one E542K mutation more than gold standard method which caused the percentage of sensitivity to get improved by 2.5% (10 to 12.5%). Our results clearly demonstrated that full-COLD PCR/HRM could detect lower levels of mutations in wild-type background as a sensitive method with simple and cost-effective procedure; therefore, it can prospectively be used in screening of patients with early-stage breast cancers.