Mechanism of Exosomal LncRNA PART1 in Esophageal Cancer Angiogenesis by Targeting miR-302a-3p/CDC25A Axis

Exosomal lncRNA SNHG12 promotes angiogenesis and breast cancer progression

OBJECTIVE

Breast cancer is one of the most prevalent malignancies in women. Exosomes are important mediators of intercellular communication; however, their regulatory mechanisms in human umbilical vein endothelial cells (HUVECs) angiogenesis in breast cancer remain unknown.

METHODS

We isolated and characterized breast cancer cell-derived exosomes and investigated their functions. Exosomal sequencing and the TCGA database were used to screen long non-coding RNA (lncRNA). In vitro and in vivo experiments were performed to investigate the role of exosomal lncRNA in HUVEC angiogenesis and tumor growth. Molecular methods were used to demonstrate the molecular mechanism of lncRNA.

RESULTS

We demonstrated that breast cancer cell-derived exosomes promoted HUVEC proliferation, tube formation, and migration. Combining exosomal sequencing results with The Cancer Genome Atlas Breast Cancer database, we screened lncRNA small nucleolar RNA host gene 12 (SNHG12), which was highly expressed in breast cancer cells. SNHG12 was also upregulated in HUVECs co-cultured with exosome-overexpressed SNHG12. Moreover, overexpression of SNHG12 in exosomes increased HUVEC proliferation and migration, whereas deletion of SNHG12 in exosomes showed the opposite effects. In vivo experiments showed that SNHG12 knockdown in exosomes inhibited breast cancer tumor growth. Transcriptome sequencing identified MMP10 as the target gene of SNHG12. Functional experiments revealed that MMP10 overexpression promoted HUVEC angiogenesis. Mechanistically, SNHG12 blocked the interaction between PBRM1 and MMP10 by directly binding to PBRM1. Moreover, exosomal SNHG12 promoted HUVEC angiogenesis via PBRM1 and MMP10.

CONCLUSIONS

In summary, our findings confirmed that exosomal SNHG12 promoted HUVEC angiogenesis via the PBRM1-MMP10 axis, leading to enhanced malignancy of breast cancer. Exosomal SNHG12 may be a novel therapeutic target for breast cancer.

Tumorigenic and tumoricidal properties of exosomes in cancers; a forward look

In recent decades, emerging data have highlighted the critical role of extracellular vesicles (EVs), especially (exosomes) Exos, in the progression and development of several cancer types. These nano-sized vesicles are released by different cell lineages within the cancer niche and maintain a suitable platform for the interchange of various signaling molecules in a paracrine manner. Based on several studies, Exos can transfer oncogenic factors to other cells, and alter the activity of immune cells, and tumor microenvironment, leading to the expansion of tumor cells and metastasis to the remote sites. It has been indicated that the cell-to-cell crosstalk is so complicated and a wide array of factors are involved in this process. How and by which mechanisms Exos can regulate the behavior of tumor cells and non-cancer cells is at the center of debate. Here, we scrutinize the molecular mechanisms involved in the oncogenic behavior of Exos released by different cell lineages of tumor parenchyma. Besides, tumoricidal properties of Exos from various stem cell (SC) types are discussed in detail.

Associations of long non-coding RNAs HOTAIR, LINC00951, POLR2E and HULC polymorphisms with the risk of esophageal and esophagogastric junction cancer in a western population: a case-control study

BACKGROUND

The incidence of single-nucleotide-polymorphisms with malignant potential in esophageal cancer tissues has only been sparsely investigated in the west. Hence, we explored the contribution of four long non-coding RNAs' polymorphisms HOTAIR rs920778, LINC00951 rs11752942, POLR2E rs3787016 and HULC rs7763881 in esophageal cancer susceptibility.

METHODS AND RESULTS

Formalin-fixed paraffin-embedded tissue specimens from 95 consecutive patients operated for esophageal/esophagogastric junction carcinoma during 25/03/2014-25/09/2018 were processed. Demographic data, histopathological parameters, surgical and oncological outcomes were collected. DNA findings of the abovementioned population were compared with 121 healthy community controls. Both populations were of European/Greek ancestry. Sixty-seven patients underwent Ivor Lewis/McKeown esophagectomy for either squamous cell esophageal carcinoma (N = 6) or esophageal/esophagogastric junction Siewert I or II adenocarcinoma (N = 61). Twenty-eight patients were subjected to extended total gastrectomy for esophagogastric junction Siewert III adenocarcinoma. Neither LINC00951 rs11752942 nor HULC rs7763881 polymorphisms were detected more frequently in esophageal cancer patients compared with healthy community subjects. A significantly higher presence of HOTAIR rs920778 TT genotype in esophagogastric junction Siewert I/II adenocarcinoma was identified. POLR2E rs3787016 C allele and CC genotypes were overrepresented in the control group, and when found in esophageal cancer carriers were associated with earlier disease stages, as well as with minor lymph node involvement and lesser metastatic potential.

CONCLUSIONS

HOTAIR rs920778 may serve as a potential therapeutic suppression target, while POLR2E rs3787016 may represent a valuable biomarker to evaluate esophageal cancer predisposition and predict treatment response and prognosis. Clinical implications of these findings need to be verified with further prospective studies with larger sample-size.

The Effect of Race/Ethnicity and MED12 Mutation on the Expression of Long Non-Coding RNAs in Uterine Leiomyoma and Myometrium

The objective of this study was to elucidate the expression of long non-coding RNA (lncRNA) in leiomyomas (Lyo) and paired myometrium (Myo) and explore the impact of race and MED12 mutation. Fold change analysis (Lyo/paired Myo) indicated the expression of 63 lncRNAs was significantly altered in the mutated group but not in the non-mutated Lyo. Additionally, 65 lncRNAs exhibited an over 1.5-fold change in the Black but not the White group. Fifteen differentially expressed lncRNAs identified with next-generation sequencing underwent qRT-PCR confirmation. Compared with Myo, the expression of TPTEP1, PART1, RPS10P7, MSC-AS1, SNHG12, CA3-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was significantly higher, while the expression of ZEB2-AS1, LINC00957, and LINC01186 was significantly lower. Comparison of normal Myo with diseased Myo showed significant differences in the expression of several lncRNAs. Analysis based on race and Lyo MED12 mutation status indicated a significantly higher expression of RPS10P7, SNHG12, LINC01449, LINC02433, and LINC02624 in Lyo from Black patients. The expression of TPTEP1, PART1, RPS10P7, MSC-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was higher, while LINC01186 was significantly lower in the MED12-mutated group. These results indicate that Lyo are characterized by aberrant lncRNA expression, which is further impacted by race and Lyo MED12 mutation status.