Bidirectional Mendelian randomization analysis of the genetic association between primary lung cancer and colorectal cancer.

BACKGROUND: With the development and popularization of low-dose chest CT technology, the diagnosis and survival rates of patients with early lung cancer (LC) have significantly improved. The occurrence of colorectal cancer (CRC) as the second primary cancer (SPC) in primary lung cancer (PLC) survivors has become an essential factor affecting the prognosis of early LC. This study explored the potential association between PLC and CRC genetically, laying a foundation for developing SPC-CRC prevention strategies after primary early LC. METHODS: Based on a two-sample bidirectional Mendelian randomization (MR) design, this study systematically screened genetic instrumental variables (IVs) based on the genome-wide association studies (GWAS) of PLC and CRC, applied inverse variance weighted (IVW) as the main method to assess the incidence association between the two cancers, and used a variety of other MR methods for supplementary analysis. Finally, the Genetic Risk Scores (GRS) method was used for secondary analysis to verify the results robustness further. RESULTS: From LC to CRC forward MR analysis, 20 genetic IVs of overall LC, 15 genetic IVs of squamous cell lung carcinoma (LUSC), and 10 genetic IVs of adenocarcinoma of the lung (LUAD) were screened. In the reverse MR analysis from CRC to LC, 47 genetic IVs for overall CRC, 37 for colon cancer, and 25 for rectal cancer were screened. The IVW method and a variety of MR methods all found that overall LC and CRC were significantly associated at the genetic level. Subgroup analysis also showed that LUSC was associated with CRC. And the results of the GRS method were consistent with those of the main analysis, confirming the robustness of the study. Our MR study found an association between LC and CRC, with an increased risk of SPC-CRC following PLC, especially LUSC. Our study provides an essential basis for the precise prevention of SPC-CRC after PLC, suggesting that we should pay more attention to the population with a history of PLC in clinical work, and pay close attention to the incidence of SPC-CRC, and carry out intervention and treatment as soon as possible.

Cancer-testis non-coding RNA LEF1-AS1 regulates the nuclear translocation of PDCD5 and suppresses its interaction with p53 signaling: a novel target for immunotherapy in esophageal squamous cell carcinoma.

Despite the improvement of current classical treatment, the prognosis of esophageal squamous cell carcinoma (ESCC) remains poor. Immunotherapy, as a new treatment method, has revolutionized the therapy of various cancer types and created more attractive for ESCC. Cancer-testis genes (CTGs), because of its characteristic expression and immunomodulation property, are considered as the ideal targets for tumor immunotherapy. However, the ESCC-specific CTGs, especially long non-coding RNA (lncRNA), has not been elucidated. In the present study, a systematic strategy was adopted to screen ESCC-specific cancer-testis lncRNA (CT-lncRNA). Collectively, 447 genes were recognized as ESCC-specific CT-lncRNAs, in particularly LEF1-AS1 showed the most aberrantly expression and clinically associated with poor outcome. Functional assays revealed that H3K27 acetylation in LEF1-AS1 promoter might give rise to the activation of LEF1-AS1 during ESCC tumorigenesis. The activated LEF1-AS1 was predominantly localized in the cytoplasm implicated in regulation of apoptosis and proliferation capacities of ESCC cells in vitro and in vivo. Further mechanistic studies unveiled that LEF1-AS1 participated in ESCC by interacting with RNA binding protein PDCD5 through weakened its nuclear translocation binding to TP53, leading to p53 degradation and disruption the transcription of downstream genes. Taken together, our findings suggest that LEF1-AS1 acts as a CT-lncRNA and might be an ideal immunotherapeutic target for clinical intervention for ESCC.

Bidirectional Mendelian randomization analysis investigating the genetic association between primary breast cancer and colorectal cancer.

Purpose: With the advancement in early diagnosis and treatment, the prognosis for individuals diagnosed with breast cancer (BC) has improved significantly. The prognosis of primary breast cancer (PBC) survivors can be significantly influenced by the occurrence of colorectal cancer (CRC) as a secondary primary cancer (SPC). The objective of this study is to explore the possible genetic association between PBC and CRC, aiming to lay a groundwork for the development of preventive strategies against SPC-CRC following BC surgery. Methods: We employed a bidirectional two-sample Mendelian randomization (MR) approach to thoroughly examine genetic instrumental variables (IVs) derived from genome-wide association studies (GWAS) conducted on PBC and CRC. And applied inverse variance weighted (IVW) and multiple other MR methods (weighted median, simple median, MR-PRESSO and MR-RAPS) to evaluate the association between the two cancers (PBC and CRC) at genetic level. Furthermore, the robustness of the findings was further confirmed through the utilization of the genetic risk score (GRS) method in a secondary analysis. Results: Forward MR analysis, a total of 179 BC genetic IVs, 25 estrogen receptor-negative (ER-) genetic IVs and 135 ER-positive (ER+) genetic IVs were screened. Reverse MR analysis, 179 genetic IVs of CRC, 25 genetic IVs of colon cancer, 135 genetic IVs of rectal cancer, 25 genetic IVs of left colon cancer and 135 genetic IVs of right colon cancer were screened. IVW and other MR methods found no significant genetic association between PBC and CRC (P > 0.05). Subgroup analysis also showed that ER- BC and ER+ BC were not correlated with the occurrence of CRC (P > 0.05). The findings of the secondary analysis using GRS were consistent with those obtained from the primary analysis, thereby confirming the robustness and reliability of this study. Conclusions: Our findings do not provide any evidence supporting the association between PBC and CRC at the genetic level. Further large-scale prospective studies are warranted to replicate our findings.