ING3 is essential for asymmetric cell division during mouse oocyte maturation

The ubiquitin E3 ligase MDM2 induces chemoresistance in colorectal cancer by degradation of ING3

Chemoresistance is an obstacle for colorectal cancer (CRC) treatment. This study investigates the role of the ubiquitin E3 ligase MDM2 in affecting cell growth and chemosensitivity in CRC cells by modifying the transcription factor inhibitor of growth protein 3 (ING3). The expression of MDM2 and ING3 in CRC tissues was predicted by bioinformatics analysis, followed by expression validation and their interaction in CRC HCT116 and LS180 cells. Ectopic overexpression or knockdown of MDM2/ING3 was performed to test their effect on proliferation and apotptosis as well as chemosensitivity of CRC cells. Finally, the effect of MDM2/ING3 expression on the in vivo tumorigenesis of CRC cells was examined through subcutaneous tumor xenograft experiment in nude mice. MDM2 promoted ubiquitin-proteasome pathway degradation of ING3 through ubiquitination and diminished its protein stability. Overexpression of MDM2 downregulated ING3 expression, which promoted CRC cell proliferation and inhibited the apoptosis. The enhancing role of MDM2 in tumorigenesis and resistance to chemotherapeutic drugs was also confirmed in vivo. Our findings highlight that MDM2 modifies the transcription factor ING3 by ubiquitination-proteasome pathway degradation, thus reducing ING3 protein stability, which finally promotes CRC cell growth and chemoresistance.

Prognostic significance of ING3 expression in patients with cancer: A systematic review and meta-analysis

Background

It has been reported that ING3 inhibits the progression of various cancers. However, some studies have shown that it promotes the development of prostate cancer. The purpose of this study was to investigate whether ING3 expression is associated with the prognosis of patients with cancer.

Materials and methods

PubMed, Cochrane Database, Embase, Medline, ScienceDirect, Scopus and Web of Science were searched until September 2022. The hazard ratio (HR)/odds ratio (OR) and 95% confidence interval (95% CI) were calculated using Stata 17 software. We used the Newcastle-Ottawa Scale (NOS) to assess the risk of bias.

Result

Seven studies involving 2371 patients with five types of cancer were included. The results showed that high expression of ING3 was negatively associated with a more advanced TNM stage (III-IV vs. I-II) (OR=0.61, 95% CI: 0.43-0.86), lymph node metastasis (OR=0.67, 95% CI: 0.49-0.90) and disease-free survival (HR=0.63, 95% CI: 0.37-0.88). However, ING3 expression was not associated with overall survival (HR=0.77, 95% CI: 0.41-1.12), tumor size (OR=0.67, 95% CI: 0.33-1.37), tumor differentiation (OR=0.86, 95% CI: 0.36-2.09) and gender (OR=1.14, 95% CI: 0.78-1.66).

Conclusion

This study showed that the expression of ING3 was associated with better prognosis, suggesting that ING3 may be a potential biomarker for cancer prognosis.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42022306354).

Differential Expression of Endogenous Retroviruses and Inflammatory Mediators in Female and Male Offspring in a Mouse Model of Maternal Immune Activation

Maternal infections during pregnancy and the consequent maternal immune activation (MIA) are the major risk factors for autism spectrum disorder (ASD). Epidemiological evidence is corroborated by the preclinical models in which MIA leads to ASD-like behavioral abnormalities and altered neuroinflammatory profiles, with an increase in pro-inflammatory cytokines and microglial markers. In addition to neuroinflammatory response, an abnormal expression of endogenous retroviruses (ERVs) has been identified in neurodevelopmental disorders and have been found to correlate with disease severity. Our aim was to evaluate the transcriptional profile of several ERV families, ERV-related genes, and inflammatory mediators (by RT real-time PCR) in mouse offspring of both sexes, prenatally exposed to polyinosinic:polycytidylic acid (Poly I:C), a synthetic double-stranded RNA molecule targeting TLR-3 that mimics viral maternal infection during pregnancy. We found that prenatal exposure to Poly I:C deregulated the expression of some ERVs and ERV-related genes both in the prefrontal cortex (PFC) and hippocampus, while no changes were detected in the blood. Interestingly, sex-related differences in the expression levels of some ERVs, ERV-related genes, and inflammatory mediators that were higher in females than in males emerged only in PFC. Our findings support the tissue specificity of ERV and ERV-related transcriptional profiles in MIA mice.

Advances in the study of CDC42 in the female reproductive system

CDC42 is a member of the Rho‐GTPase family and is involved in a variety of cellular functions including regulation of cell cycle progression, constitution of the actin backbone and membrane transport. In particular, CDC42 plays a key role in the establishment of polarity in female vertebrate oocytes, and essential to this major regulatory role is its local occupation of specific regions of the cell to ensure that the contractile ring is assembled at the right time and place to ensure proper gametogenesis. The multifactor controlled ‘inactivation‐activation’ process of CDC42 also allows it to play an important role in the multilevel signalling network, and the synergistic regulation of multiple genes ensures maximum precision during gametogenesis. The purpose of this paper is to review the role of CDC42 in the control of gametogenesis and to explore its related mechanisms, with the aim of further understanding the great research potential of CDC42 in female vertebrate germ cells and its future clinical translation.

Overexpression of ING3 is associated with attenuation of migration and invasion in breast cancer

Inhibitor of growth 3 (ING3) has been identified as a potential cancer drug target, but little is known about its role in breast cancer. Thus, the present study aimed to investigate ING3 expression in breast cancer, its clinical value, and how ING3 influences the migration and invasion of breast cancer cells. The Cancer Genome Atlas and UALCAN databases were used to analyze ING3 expression in cancer tissues and normal tissues. Survival analysis was performed using the UALCAN, UCSC Xena and KM-plot databases. In addition, reverse transcription-quantitative PCR and western blot analyses were performed to detect ING3 mRNA and protein expression levels. ING3 was overexpressed via lentiviral vector transfection, while the Transwell and wound healing assays were performed to assess the cell migratory and invasive abilities. Protein interaction and pathway analyses were performed using the GeneMANIA and Kyoto Encyclopedia of Genes and Genomes databases, respectively. The results demonstrated that ING3 expression was significantly lower in cancer tissues compared with normal tissues (P<0.05). In addition, luminal A and human epidermal growth factor receptor 2 (HER2)-enriched breast cancer tissues expressed lower levels of ING3 compared with normal breast tissues. Notably, statistically significant differences were observed in long-term survival between patients with luminal A (P=0.04) and HER2-enriched (P=0.008) breast cancer, with high and low expression levels of ING3. The results of the Transwell migration and invasion assays demonstrated that overexpression of ING3 significantly inhibited the migratory and invasive abilities of MCF7 (P<0.05) and HCC1937 (P<0.05) cells. The results of the wound healing assay demonstrated that the percentage wound closure significantly decreased in cells transfected with LV5-ING3 compared with the negative control group at 12 h (P<0.05) and 24 h (P<0.01). The PI3K/AKT, JAK/STAT, NF-κB and Wnt/β-catenin pathways are the potential pathways regulated by ING3. Notably, overexpression of ING3 inhibited migration and invasion in vitro. However, further studies are required to determine whether ING3 regulates the biological behavior of breast cancer via tumor-related pathways.

Focus-ING on DNA Integrity: Implication of ING Proteins in Cell Cycle Regulation and DNA Repair Modulation

The ING family of tumor suppressor genes is composed of five members (ING1-5) involved in cell cycle regulation, DNA damage response, apoptosis and senescence. All ING proteins belong to various HAT or HDAC complexes and participate in chromatin remodeling that is essential for genomic stability and signaling pathways. The gatekeeper functions of the INGs are well described by their role in the negative regulation of the cell cycle, notably by modulating the stability of p53 or the p300 HAT activity. However, the caretaker functions are described only for ING1, ING2 and ING3. This is due to their involvement in DNA repair such as ING1 that participates not only in NERs after UV-induced damage, but also in DSB repair in which ING2 and ING3 are required for accumulation of ATM, 53BP1 and BRCA1 near the lesion and for the subsequent repair. This review summarizes evidence of the critical roles of ING proteins in cell cycle regulation and DNA repair to maintain genomic stability.

Enhanced Kat3A/Catenin transcription: a common mechanism of therapeutic resistance

Cancers are heterogeneous at the cellular level. Cancer stem cells/tumor initiating cells (CSC/TIC) both initiate tumorigenesis and are responsible for therapeutic resistance and disease relapse. Elimination of CSC/TIC should therefore be able to reverse therapy resistance. In principle, this could be accomplished by either targeting cancer stem cell surface markers or "stemness" pathways. Although the successful therapeutic elimination of "cancer stemness" is a critical goal, it is complex in that it should be achieved without depletion of or increases in somatic mutations in normal tissue stem cell populations. In this perspective, we will discuss the prospects for this goal via pharmacologically targeting differential Kat3 coactivator/Catenin usage, a fundamental transcriptional control mechanism in stem cell biology.

ING3 is required for ATM signaling and DNA repair in response to DNA double strand breaks

Inhibitor of Growth 3 (ING3) is a candidate tumor suppressor gene whose expression is lost in tumors such as hepatocellular carcinoma, head and neck squamous cell carcinoma and melanoma. In the present study, we show that ING3-depleted human cells and yeast cells deleted for its ortholog YNG2 are sensitive to DNA damage suggesting a conserved role in response to such stress. In human cells, ING3 is recruited to DNA double strand breaks and is required for ATM activation. Remarkably, in response to doxorubicin, ATM activation is dependent on ING3 but not on TIP60, whose recruitment to DNA breaks also depends on ING3. These events lead to ATM-mediated phosphorylation of NBS1 and the subsequent recruitment of RNF8, RNF168, 53BP1, and BRCA1, which are major mediators of the DNA damage response. Accordingly, upon genotoxic stress, DNA repair by non-homologous end joining (NHEJ) or homologous recombination (HR) were impaired in absence of ING3. Finally, immunoglobulin class switch recombination (CSR), a physiological mechanism requiring NHEJ repair, was impaired in the absence of ING3. Since deregulation of DNA double strand break repair is associated with genomic instability, we propose a novel function of ING3 as a caretaker tumor suppressor involved in the DNA damage signaling and repair.

Oocyte-specific gene Oog1 suppresses the expression of spermatogenesis-specific genes in oocytes

Oog1, an oocyte-specific gene that encodes a protein of 425 amino acids, is present in five copies on mouse chromosomes 4 and 12. In mouse oocytes, Oog1 mRNA expression begins at embryonic day 15.5 and almost disappears by the late two-cell stage. Meanwhile, OOG1 protein is detectable in oocytes in ovarian cysts and disappears by the four-cell stage; the protein is transported to the nucleus in late one-cell to early two-cell stage embryos. In this study, we examined the role of Oog1 during oogenesis in mice. Oog1 RNAi-transgenic mice were generated by expressing double-stranded hairpin Oog1 RNA, which is processed into siRNAs targeting Oog1 mRNA. Quantitative RT-PCR revealed that the amount of Oog1 mRNA was dramatically reduced in oocytes obtained from Oog1-knockdown mice, whereas the abundance of spermatogenesis-associated transcripts (Klhl10, Tekt2, Tdrd6, and Tnp2) was increased in Oog1 knockdown ovaries. Tdrd6 is involved in the formation of the chromatoid body, Tnp2 contributes to the formation of sperm heads, Tekt2 is required for the formation of ciliary and flagellar microtubules, and Klhl10 plays a key role in the elongated sperm differentiation. These results indicate that Oog1 down-regulates the expression of spermatogenesis-associated genes in female germ cells, allowing them to develop normally into oocytes.

ING5 activity in self-renewal of glioblastoma stem cells via calcium and follicle stimulating hormone pathways

Stem cell-like brain tumor initiating cells (BTICs) cause recurrence of glioblastomas, with BTIC 'stemness' affected by epigenetic mechanisms. The ING family of epigenetic regulators (ING1-5) function by targeting histone acetyltransferase (HAT) or histone deacetylase complexes to the H3K4me3 mark to alter histone acetylation and subsequently, gene expression. Here we find that ectopic expression of ING5, the targeting subunit of HBO1, MOZ and MORF HAT complexes increases expression of the Oct4, Olig2 and Nestin stem cell markers, promotes self-renewal, prevents lineage differentiation and increases stem cell pools in BTIC populations. This activity requires the plant homeodomain region of ING5 that interacts specifically with the H3K4me3 mark. ING5 also enhances PI3K/AKT and MEK/ERK activity to sustain self-renewal of BTICs over serial passage of stem cell-like spheres. ING5 exerts these effects by activating transcription of calcium channel and follicle stimulating hormone pathway genes. In silico analyses of The Cancer Genome Atlas data suggest that ING5 is a positive regulator of BTIC stemness, whose expression negatively correlates with patient prognosis, especially in the Proneural and Classical subtypes, and in tumors with low SOX2 expression. These data suggest that altering histone acetylation status and signaling pathways induced by ING5 may provide useful clinical strategies to target tumor resistance and recurrence in glioblastoma.

Immunohistochemical profile of ING3 protein in normal and cancerous tissues

The inhibitor of growth family, member 3 (ING3) protein may be capable of blocking the cell cycle via activating p53-transactivated promoters of p21 and Bcl2-associated X protein, and may induce apoptosis via a Fas/caspase-8-dependent signaling pathway. In the present study, immunohistochemistry was performed in order to characterize the expression profile of ING3 protein in tissue microarrays containing mouse and human normal tissue, human hepatocellular (n=62), renal clear cell (n=62), pancreatic (n=62), esophageal squamous cell (n=45), cervical squamous cell (n=31), breast (n=144), gastric (n=196), colorectal (n=96), ovarian (n=208), endometrial (n=96) and lung carcinoma (n=192). In mouse tissue, ING3 protein was positively detected in the cytoplasm of cardiomyocytes, kidney and skeletal muscle cells, and was additionally detected in the cytoplasm and nucleus of bronchial and alveolar epithelium, gastric and intestinal gland, and mammary gland cells. In human tissues, ING3 protein was principally distributed in the cytoplasm, but was observed in the cytoplasm and nucleus of tongue, esophagus, stomach, intestine, lung, skin, appendix, bladder, cervix and breast cells. ING3 immunoreactivity was strongly detected in the stomach, skin and cervical tissues, whereas a weak signal was detected in the cerebellum, brain stem, thymus, liver, skeletal muscle, testis and prostate. In total, ING3-positive specimens were identified in 424 of 1,194 tested cancer entities (35.5%). In a number of cases, ING3 expression was observed to be restricted to the cytoplasm and nucleus, excluding the cytoplasmic distribution identified in breast and hepatocellular carcinoma. Among these cases, ING3 was more frequently expressed in breast and gynecological types of cancer, including ovarian (59.2%), endometrial (47.9%), breast (38.9%) and cervical (35.5%) cancer. ING3-positive cases were more rare in renal clear cell (17.7%), hepatocellular (16.1%) and esophageal carcinoma (17.8%). It is suggested that ING3 may be involved in the repair and regeneration of organs or tissues, and may be closely associated with gynecological carcinogenesis.

INGs are potential drug targets for cancer

PURPOSE

The inhibitor of growth (ING) family consists of ING1, ING2, ING3, ING4 and ING5, which function as the type II tumor suppressors. INGs regulate cell proliferation, senescence, apoptosis, differentiation, angiogenesis, DNA repair, metastasis, and invasion by multiple pathways. In addition, INGs increase cancer cell sensitivity for chemotherapy and radiotherapy, while clinical observations show that INGs are frequently lost in some types of cancers. The aim of the study was to summarize the recent progress regarding INGs regulating tumor progression.

METHODS

The literatures of INGs regulating tumor progression were searched and assayed.

RESULTS

The regulating signaling pathways of ING1, ING2, ING3 or ING4 on tumor progression were shown. The mechanisms of INGs on tumor suppression were also assayed.

CONCLUSIONS

This review better summarized the signaling mechanism of INGs on tumor suppression, which provides a candidate therapy strategy for cancers.

Comparative analysis of blood and saliva expression profiles in chronic and refractory periodontitis patients

Background

This study aimed to identify characteristic representative genes through a comparative analysis of gene expression profiles in the blood and saliva of chronic periodontitis (CP) and refractory periodontitis (RP) patients to provide new treatment strategies that may be helpful in the treatment of different forms of periodontitis.

Methods

GSE43525 was downloaded from Gene Expression Omnibus. In the dataset, thirteen samples were from blood including 4 controls, 4 CP and 5 RP samples, and ten samples were from saliva including 3 controls, 4 CP and 3 RP samples. After comparing the CP and RP samples, differentially expressed genes (DEGs) between these two types of periodontitis in the blood and saliva samples were identified by an LIMMA package. Then, functional and pathway enrichment analyses were performed by DAVID and KOBAS, respectively. The significantly associated miRNAs in CP and RP were searched by WebGestalt.

Results

In total, 213 DEGs in CP and 45 DEGs in RP were identified. Functional enrichment showed that the DEGs of CP were mainly enriched in ribosome and regulation of apoptosis-related pathways in blood as well as saliva, while the DEGs of RP were significantly enriched in immune responses and response to organic substance-related pathways. Several miRNAs, such as miR-381 and miR-494, were identified as being closely associated with CP. In addition, CD24, EST1, MTSS1, ING3, CCND2 and SYNE2 might be potential targets for diagnosis and treatment of CP.

Conclusion

The identified DEGs and miRNAs might be potential targets for the treatment of chronic and refractory periodontitis.

CHD1 acts via the Hmgpi pathway to regulate mouse early embryogenesis

The protein CHD1 is a member of the family of ATPase-dependent chromatin remodeling factors. CHD1, which recognizes trimethylated histone H3 lysine 4, has been implicated in transcriptional activation in organisms ranging from yeast to humans. It is required for pre-mRNA maturation, maintenance of mouse embryonic stem cell pluripotency and rapid growth of the mouse epiblast. However, the function(s) of CHD1 in mouse preimplantation embryos has not yet been examined. Here, we show that loss of CHD1 function led to embryonic lethality after implantation. In mouse embryos in which Chd1 was targeted by siRNA microinjection, the expression of the key regulators of cell fate specification Pou5f1 (also known as Oct4), Nanog and Cdx2 was dramatically decreased, starting at mid-preimplantation gene activation (MGA). Moreover, expression of Hmgpi and Klf5, which regulate Pou5f1, Nanog and Cdx2, was also significantly suppressed at zygotic gene activation (ZGA). Suppression of Hmgpi expression in Chd1-knockdown embryos continued until the blastocyst stage, whereas suppression of Klf5 expression was relieved by the morula stage. Next, we rescued HMGPI expression via Hmgpi mRNA microinjection in Chd1-knockdown embryos. Consequently, Pou5f1, Nanog and Cdx2 expression was restored at MGA and live offspring were recovered. These findings indicate that CHD1 plays important roles in mouse early embryogenesis via activation of Hmgpi at ZGA.

Histone methyltransferase Smyd3 regulates early embryonic lineage commitment in mice

SET and MYND domain-containing protein 3 (Smyd3) is a histone H3 lysine 4 (H3K4) di- and tri-methyltransferase that forms a transcriptional complex with RNA polymerase II and activates the transcription of oncogenes and cell cycle genes in human cancer cells. However, the study of Smyd3 in mammalian early embryonic development has not yet been addressed. In the present study, we investigated the expression pattern of Smyd3 in mouse preimplantation embryos and the effects of RNA interference (RNAi)-mediated Smyd3 repression on the development of mouse embryos. We showed that Smyd3 mRNA levels increased after the two-cell stage, peaked at the four-cell stage, and gradually decreased thereafter. Moreover, in two-cell to eight-cell embryos, SMYD3 staining was more intense in the nuclei than it was in the cytoplasm. In Smyd3-knockdown embryos, the percentage of inner cell mass (ICM)-derived colony formation and trophectoderm (TE)-derived cell attachment were significantly decreased, which resulted in a reduction in the number of viable offspring. Furthermore, the expression of Oct4 and Cdx2 during mid-preimplantation gene activation was significantly decreased in Smyd3-knockdown embryos. In addition, the transcription levels of ICM and epiblast markers, such as Oct4, Nanog, and Sox2, the transcription levels of primitive endoderm markers, such as Gata6, and the transcription levels of TE markers, such as Cdx2 and Eomes, were significantly decreased in Smyd3-knockdown blastocysts. These findings indicate that SMYD3 plays an important role in early embryonic lineage commitment and peri-implantation development through the activation of lineage-specific genes.

Keep-ING balance: tumor suppression by epigenetic regulation

Cancer cells accumulate genetic and epigenetic changes that alter gene expression to drive tumorigenesis. Epigenetic silencing of tumor suppressor, cell cycle, differentiation and DNA repair genes contributes to neoplastic transformation. The ING (inhibitor of growth) proteins (ING1-ING5) have emerged as a versatile family of growth regulators, phospholipid effectors, histone mark sensors and core components of HDAC1/2 - and several HAT chromatin-modifying complexes. This review will describe the characteristic pathways by which ING family proteins differentially affect the Hallmarks of Cancer and highlight the various epigenetic mechanisms by which they regulate gene expression. Finally, we will discuss their potentials as biomarkers and therapeutic targets in epigenetic treatment strategies.