p33ING1b regulates acetylation of p53 in oral squamous cell carcinoma via SIR2

HDAC5 deacetylates c-Myc and facilitates cell cycle progression in hepatocellular carcinoma cells

Histone deacetylase 5 (HDAC5) is an enzyme that deacetylates lysine residues on the N-terminal of histones and other proteins. It has been reported that HDAC5 deacetylates p53, the critical factor regulating cell cycle, in response to cellular stress, but the transcriptional products haven't been identified. Herein, we used p53 signaling pathway qPCR-chip to determine how HDAC5-mediated deacetylation of p53 affects cell cycle. However, validation using immunoblotting analysis revealed that acetylation of p53 at K120 impacted little to the expression of the genes identified using the qPCR-chip, indicating HDAC5 might deacetylate some other proteins to facilitate cell cycle via transactivating the differentially expressed genes determined by the qPCR-chip. The subsequent assays demonstrated that HDAC5 deacetylated c-Myc at K143 and K157 to facilitate the transactivation of CDK1, CDK4, and CDC25C, promoting cell cycle progression of hepatocellular carcinoma (HCC). This study shows that HDAC5 plays important roles in modulating deacetylation of c-Myc and regulating cell cycle progression, and it proves that LMK-235, the inhibitor targeting HDAC5 potentially serves as a drug for combating HCC via promoting acetylation of c-Myc at K143 and K157.

Decreased Nuclear Immunoexpression of ING3 is a Frequent Event in Lip Carcinogenesis

PURPOSE

Evaluate the immunohistochemical expression of the ING3 in actinic cheilitis and squamous cell carcinoma of the lower lip.

METHODS

Forty-five specimens of actinic cheilitis and 48 specimens of squamous cell carcinoma of the lower lip were submitted to immunohistochemical detection of ING3. The protein expression in different cellular sublocations was compared between the two groups, and associations with the clinicopathological variables were analyzed. A significance level of 5% was adopted for all tests.

RESULTS

Deaths were significantly more frequent in tumors with a high histopathological risk score (p < 0.05). In actinic cheilitis, significant differences were found in the nucleus-cytoplasmic expression of ING3 and expression restricted to the cytoplasm with binary histopathological grading (p < 0.05). In squamous cell carcinoma of the lower lip, there was no statistically significant difference when comparing ING3 expressions with clinical and morphological parameters (p > 0.05). Nucleo-cytoplasmic ING3 expression was significantly lower in squamous cell carcinoma of the lower lip when compared to actinic cheilitis (p < 0.05) and the expression restricted to the cytoplasm was significantly higher in squamous cell carcinoma of the lower lip (p < 0.05).

CONCLUSION

The results of this study suggest that there is a marked decrease in the nuclear expression of ING3 as malignant progression occurs, indicating an impaired tumor suppressor function of this protein in actinic cheilitis and squamous cell carcinoma of the lower lip.

Targeting ferroptosis as a potential strategy to overcome the resistance of cisplatin in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a crucial public health problem, accounting for approximately 2% of all cancers globally and 90% of oral malignancies over the world. Unfortunately, despite the achievements in surgery, radiotherapy, and chemotherapy techniques over the past decades, OSCC patients still low 5-year survival rate. Cisplatin, a platinum-containing drug, serves as one of the first-line chemotherapeutic agents of OSCC. However, the resistance to cisplatin significantly limits the clinical practice and is a crucial factor in tumor recurrence and metastasis after conventional treatments. Ferroptosis is an iron-based form of cell death, which is initiated by the intracellular accumulation of lipid peroxidation and reactive oxygen species (ROS). Interestingly, cisplatin-resistant OSCC cells exhibit lower level of ROS and lipid peroxidation compared to sensitive cells. The reduced ferroptosis in cisplatin resistance cells indicates the potential relationship between cisplatin resistance and ferroptosis, which is proved by recent studies showing that in colorectal cancer cells. However, the modulation pathway of ferroptosis reversing cisplatin resistance in OSCC cells still remains unclear. This article aims to concisely summarize the molecular mechanisms and evaluate the relationship between ferroptosis and cisplatin resistance OSCC cells, thereby providing novel strategies for overcoming cisplatin resistance and developing new therapeutic approaches.

Combined time-restricted feeding and cisplatin enhance the anti-tumor effects in cisplatin-resistant and -sensitive lung cancer cells

Combination therapy as an important treatment option for lung cancer has been attracting attention due to the primary and acquired resistance of chemotherapeutic drugs in the clinical application. In the present study, as a new therapy strategy, concomitant treatment with time-restricted feeding (TRF) plus cisplatin (DDP) on lung cancer growth was investigated in DDP-resistant and DDP-sensitive lung cancer cells. We first found that TRF significantly enhanced the drug susceptibility of DDP in DDP-resistant A549 (A549/DDP) cell line, illustrated by reversing the inhibitory concentration 50 (IC₅₀) values of A549/DDP cells to normal level of parental A549 cells. We also found that TRF markedly enhanced DDP inhibition on cell proliferation, migration, as well as promoted apoptosis compared to the DDP alone group in A549, H460 and A549/DDP cells lines. We further revealed that the synergistic anti-tumor effect of combined DDP and TRF was greater than that of combined DDP and simulated fasting condition (STS), a known anti-tumor cellular medium. Moreover, mRNA sequence analysis from A549/DDP cell line demonstrated the synergistic anti-tumor effect involved in upregulated pathways in p53 signaling pathway and apoptosis. Notably, compared with the DDP alone group, combination of TRF and DDP robustly upregulated the P53 protein expression without mRNA level change by regulating its stability via promoting protein synthesis and inhibiting degradation, revealed by cycloheximide and MG132 experiments. Collectively, our results suggested that TRF in combination with cisplatin might be an additional novel therapeutic strategy for patients with lung cancer.

Aquaporins: A new target for traditional Chinese medicine in the treatment of digestive system diseases

Aquaporins (AQPs) are a family of transmembrane proteins expressed in various organ systems. Many studies have shown that the abnormal expression of AQPs is associated with gastrointestinal, skin, liver, kidneys, edema, cancer, and other diseases. The majority of AQPs are expressed in the digestive system and have important implications for the physiopathology of the gastrointestinal tract as well as other tissues and organs. AQP regulators can prevent and treat most gastrointestinal-related diseases, such as colorectal cancer, gastric ulcer, and gastric cancer. Although recent studies have proposed clinically relevant AQP-targeted therapies, such as the development of AQP inhibitors, clinical trials are still lacking and there are many difficulties. Traditional Chinese medicine (TCM) has been used in China for thousands of years to prevent, treat and diagnose diseases, and is under the guidance of Chinese medicine (CM) theory. Herein, we review the latest research on the regulation of AQPs by TCMs and their active components, including Rhei Radix et Rhizoma, Atractylodis macrocephalae Rhizoma, Salviae miltiorrhizae Radix et Rhizoma, Poria, Astragali radix, and another 26 TCMs, as well as active components, which include the active components include anthraquinones, saponins, polysaccharides, and flavonoid glycosides. Through our review and discussion of numerous studies, we attempt to explore the regulatory effects of TCMs and their active components on AQP expression in the corresponding parts of the body in terms of the Triple Energizer concept in Chinese medicine defined as "upper energizer, middle energizer, and lower energizer,"so as to offer unique opportunities for the development of AQP-related therapeutic drugs for digestive system diseases.

ING Tumour Suppressors and ING Splice Variants as Coregulators of the Androgen Receptor Signalling in Prostate Cancer

Prevention and overcoming castration resistance of prostate cancer (PC) remains one of the main unsolved problems in modern oncology. Hence, many studies are focused on the investigation of novel androgen receptor (AR) regulators that could serve as potential drug targets in disease therapy. Among such factors, inhibitor of growth (ING) proteins were identified. Some ING proteins act as AR transcriptional coregulators, indicating their relevance for PC research. The ING family consists of five protein-coding genes from ING1 to ING5 and pseudogene INGX. The ING genes were revealed through their sequence homology to the first identified ING1 from an in vivo screen. ING factors are a part of histone modification complexes. With the help of the conserved plant homeodomain (PHD) motif, ING factors bind to Histone 3 Lysine 4 (H3K4) methylation mark with a stronger affinity to the highest methylation grade H3K4me3 and recruit histone acetyltransferases (HAT) and histone deacetylases (HDAC) to chromatin. ING1 and ING2 are core subunits of mSIN3a-HDAC corepressor complexes, whereas ING3–5 interact with different HAT complexes that serve as coactivators. ING members belong to type II tumour suppressors and are frequently downregulated in many types of malignancies, including PC. As the family name indicates, ING proteins are able to inhibit cell growth and tumour development via regulation of cell cycle and cancer-relevant pathways such as apoptosis, cellular senescence, DNA repair, cell migration, invasion, and angiogenesis. Many ING splice variants that enhance the diversity of ING activity were discovered. However, it seems that the existence of multiple ING splice variants is underestimated, since alternative splice variants, such as the AR coregulators ING1 and ING3, counteract full-length ING and thus play an opposite functional role. These results open a novel prospective investigation direction in understanding ING factors biology in PC and other malignancies.