The genomic instability may lead to an initiation of cancer in many organisms. Homologous recombination repair (HRR) is vital in maintaining cellular genomic stability. RAD51 associated protein 1 (RAD51AP1), which plays a crucial role in HRR and primarily participates in forming D-loop, was reported as an essential protein for maintaining cellular genomic stability. However, recent studies showed that RAD51AP1 was significantly overexpressed in various cancer types and correlated with poor prognosis. These results suggested that RAD51AP1 may play a significant pro-cancer effect in multiple cancers. The underlying mechanism is still unclear. Cancer stemness-maintaining effects of RAD51AP1 might be considered as the most reliable mechanism. Meanwhile, RAD51AP1 also promoted resistance to radiation therapy and chemotherapy in many cancers. Thus, researches focused on RAD51AP1, and its regulatory molecules may provide new targets for overcoming cancer progression and treatment resistance. Here, we reviewed the latest research on RAD51AP1 in cancers and summarized its differential expression and prognostic implications. In this review, we also outlined the potential mechanisms of its pro-cancer and drug resistance-promoting effects to provide several potential directions for further research.
.
Humans ; DNA-Binding Proteins/metabolism* ; RNA-Binding Proteins/metabolism* ; Lung Neoplasms ; DNA Repair ; Genomic Instability ; Rad51 Recombinase/metabolism*

OBJECTIVE: To investigate the expression and clinical significance of RAD51 in laryngocarcinoma. METHOD: The expression of RAD51 in laryngocarcinoma and polyp of vocal cord tissues were determined by immunohistochemical staining. The results were analyzed and compared with the clinical stage, lymph node metastasis and pathologic grade. RESULT: (1) The expression of RAD51 in laryngocarcinoma group was extremely stronger than that in polyp of vocal cord group (P < 0.01). (2) There was significant difference for RAD51 expression in cancer cells between earlier clinical stage group and advanced clinical stage group (P < 0.01). (3) There was significant difference for RAD51 expression in different pathologic grades (P < 0.05). (4) There was also significant difference for RAD51 expression between groups with and without lymph node metastasis. CONCLUSION RAD51 may play a critical role in tumorigenesis of laryngocarcinoma. RAD51 may be a potential marker for clinical diagnosis and treatment of Laryngocarcinoma. It may be significant in predicting clinical stage, pathologic grade and metastasis.
Female ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Polyps ; metabolism ; pathology ; Prognosis ; Rad51 Recombinase ; metabolism ; Vocal Cords ; pathology

BACKGROUNDOvarian serous adenocarcinoma can be divided into low- and high-grade tumors, which exhibit substantial differences in pathogenesis, clinicopathology, and prognosis. This study aimed to investigate the differences in the PH domain leucine-rich repeat protein phosphatase (PHLPP), forkhead homeobox type O 3a (FoxO3a), and RAD51 protein expressions, and their associations with prognosis in patients with low- and high-grade ovarian serous adenocarcinomas.

METHODSThe PHLPP, FoxO3a, and RAD51 protein expressions were examined in 94 high- and 26 low-grade ovarian serous adenocarcinomas by immunohistochemistry. The differences in expression and their relationships with pathological features and prognosis were analyzed.

RESULTSIn high-grade serous adenocarcinomas, the positive rates of PHLPP and FoxO3a were 24.5% and 26.6%, while in low-grade tumors, they were 23.1% and 26.9%, respectively (P < 0.05 vs. the control specimens; low- vs. high-grade: P > 0.05). The positive rates of RAD51 were 70.2% and 65.4% in high- and low-grade serous adenocarcinomas, respectively (P < 0.05 vs. the control specimens; low- vs. high-grade: P > 0.05). Meanwhile, in high-grade tumors, Stage III/IV tumors and lymph node and omental metastases were significantly associated with lower PHLPP and FoxO3a and higher RAD51 expression. The 5-year survival rates of patients with PHLPP- and FoxO3a-positive high-grade tumors (43.5% and 36.0%) were significantly higher than in patients with PHLPP-negative tumors (5.6% and 7.2%, respectively; P< 0.05). Similarly, the 5-year survival rate of RAD51-positive patients (3.0%) was significantly lower than in negative patients (42.9%; P< 0.05). In low-grade tumors, the PHLPP, FoxO3a, and RAD51 expressions were not significantly correlated with lymph node metastasis, omental metastasis, Federation of Gynecology and Obstetrics stage, or prognosis.

CONCLUSIONSAbnormal PHLPP, FoxO3a, and RAD51 protein expressions may be involved in the development of high- and low-grade ovarian serous adenocarcinomas, suggesting common molecular pathways. Decreased PHLPP and FoxO3a and increased RAD51 protein expression may be important molecular markers for poor prognosis, and RAD51 may be an independent prognosis factor, of high-grade, but not low-grade, ovarian serous adenocarcinomas.

Adult ; Aged ; Biomarkers, Tumor ; metabolism ; Cystadenocarcinoma, Serous ; metabolism ; pathology ; Female ; Forkhead Box Protein O3 ; metabolism ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Middle Aged ; Neoplasm Staging ; Nuclear Proteins ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; Phosphoprotein Phosphatases ; metabolism ; Prognosis ; Rad51 Recombinase ; metabolism

The transition from spermatogonia to spermatocytes and the initiation of meiosis are key steps in spermatogenesis and are precisely regulated by a plethora of proteins. However, the underlying molecular mechanism remains largely unknown. Here, we report that Src homology domain tyrosine phosphatase 2 (Shp2; encoded by the protein tyrosine phosphatase, nonreceptor type 11 [Ptpn11] gene) is abundant in spermatogonia but markedly decreases in meiotic spermatocytes. Conditional knockout of Shp2 in spermatogonia in mice using stimulated by retinoic acid gene 8 (Stra8)-cre enhanced spermatogonial differentiation and disturbed the meiotic process. Depletion of Shp2 in spermatogonia caused many meiotic spermatocytes to die; moreover, the surviving spermatocytes reached the leptotene stage early at postnatal day 9 (PN9) and the pachytene stage at PN11-13. In preleptotene spermatocytes, Shp2 deletion disrupted the expression of meiotic genes, such as disrupted meiotic cDNA 1 (Dmc1), DNA repair recombinase rad51 (Rad51), and structural maintenance of chromosome 3 (Smc3), and these deficiencies interrupted spermatocyte meiosis. In GC-1 cells cultured in vitro, Shp2 knockdown suppressed the retinoic acid (RA)-induced phosphorylation of extracellular-regulated protein kinase (Erk) and protein kinase B (Akt/PKB) and the expression of target genes such as synaptonemal complex protein 3 (Sycp3) and Dmc1. Together, these data suggest that Shp2 plays a crucial role in spermatogenesis by governing the transition from spermatogonia to spermatocytes and by mediating meiotic progression through regulating gene transcription, thus providing a potential treatment target for male infertility.
Animals ; Cell Cycle Proteins/genetics* ; Cell Line ; Cell Survival ; Chondroitin Sulfate Proteoglycans/genetics* ; Chromosomal Proteins, Non-Histone/genetics* ; Gene Expression Regulation ; Gene Knockdown Techniques ; Infertility, Male ; Male ; Meiosis/genetics* ; Mice ; Mice, Knockout ; Mice, Transgenic ; Phosphate-Binding Proteins/genetics* ; Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics* ; Rad51 Recombinase/genetics* ; Real-Time Polymerase Chain Reaction ; Spermatocytes/metabolism* ; Spermatogenesis/genetics* ; Spermatogonia/metabolism*