Propofol suppresses colorectal cancer development by the circ-PABPN1/miR-638/SRSF1 axis

Targeting the "tumor microenvironment": RNA-binding proteins in the spotlight in colorectal cancer therapy

Colorectal cancer (CRC) is the third most common cancer and has the second highest mortality rate among cancers. The development of CRC involves both genetic and epigenetic abnormalities, and recent research has focused on exploring the ex-transcriptome, particularly post-transcriptional modifications. RNA-binding proteins (RBPs) are emerging epigenetic regulators that play crucial roles in post-transcriptional events. Dysregulation of RBPs can result in aberrant expression of downstream target genes, thereby affecting the progression of colorectal tumors and the prognosis of patients. Recent studies have shown that RBPs can influence CRC pathogenesis and progression by regulating various components of the tumor microenvironment (TME). Although previous research on RBPs has primarily focused on their direct regulation of colorectal tumor development, their involvement in the remodeling of the TME has not been systematically reported. This review aims to highlight the significant role of RBPs in the intricate interactions within the CRC tumor microenvironment, including tumor immune microenvironment, inflammatory microenvironment, extracellular matrix, tumor vasculature, and CRC cancer stem cells. We also highlight several compounds under investigation for RBP-TME-based treatment of CRC, including small molecule inhibitors such as antisense oligonucleotides (ASOs), siRNAs, agonists, gene manipulation, and tumor vaccines. The insights gained from this review may lead to the development of RBP-based targeted novel therapeutic strategies aimed at modulating the TME, potentially inhibiting the progression and metastasis of CRC.

Propofol inhibits the proliferation, invasion, migration, and angiogenesis of oral squamous cell carcinoma through circ_0008898-mediated pathway

Propofol has been shown to inhibit oral squamous cell carcinoma (OSCC) progression. However, it is not clear whether propofol mediates OSCC progression through regulating circular RNA (circRNA) network. Quantitative real-time PCR was used to detect circ_0008898, miR-545-3p, and CT10 regulator of kinase-like protein (CRKL) expression. Cell functions were determined using CCK8 assay, Edu staining, MTT assay, transwell assay, wound healing assay, tube formation assay, and flow cytometry. Protein levels were examined by western blot analysis. RNA interaction was confirmed by dual-luciferase reporter assay and RIP assay. Our data showed that propofol repressed OSCC cell proliferation, invasion, migration, angiogenesis, and promoted apoptosis. circ_0008898 was highly expressed in OSCC, and its expression could be decreased by propofol. circ_0008898 silencing aggravated the suppressive effect of propofol on OSCC progression. In the mechanism, circ_0008898 could target miR-545-3p to positively regulate CRKL. MiR-545-3p inhibitor abolished the regulation of circ_0008898 silencing on propofol-mediated OSCC cell progression. MiR-545-3p inhibited the progression of propofol-treated OSCC cells, and this effect was reversed by CRKL overexpression. Also, circ_0008898 knockdown reduced OSCC tumor growth by regulating miR-545-3p/CRKL. In conclusion, propofol suppressed OSCC progression, which was achieved through regulating the circ_0008898/miR-545-3p/CRKL axis.

Serine and arginine rich splicing factor 1‑regulated microtubule interacting and trafficking domain containing 1 affects colorectal cancer progression and ferroptosis

As the third most common type of cancer globally, colorectal cancer (CC) is a prevalent digestive malignancy, with the second highest mortality rate among all types of cancer. It has been reported that microtubule interacting and trafficking domain containing 1 (MITD1) serves a pivotal role in the initiation and progression of diverse types of tumors. Nevertheless, the underlying mechanism of MITD1 in CC has not been previously investigated. The ENCORI and GEPIA databases were used to investigate the expression levels of MITD1 in patients with CC. Immunohistochemistry was used to detect the expression of MITD1 in cancer tissues obtained from patients with CC, while its mRNA and protein expression levels in CC cell lines were determined by reverse transcription-quantitative PCR and western blot analysis, respectively. Subsequently, MITD1 was knocked down in CC cells using an interference plasmid and Cell Counting Kit 8, colony formation, as well as EdU assays were performed to assess cell proliferation. Concurrently, wound healing and Transwell assays were performed to evaluate the migration and invasion abilities of CC cells. Lipid reactive oxygen species (ROS) levels were determined by BODIPY 581/591 C11 staining. In addition, the levels of oxidative stress markers and those of total iron were measured using the corresponding kits. Furthermore, the association between serine and arginine rich splicing factor 1 (SRSF1) and MITD1 was verified by RNA immunoprecipitation and actinomycin D experiments. Finally, to further uncover the mechanism of MITD1, SRSF1 was overexpressed and MITD1 was silenced in CC cells. The results demonstrated that the expression of MITD1 was abnormally elevated in CC tissues and CC cell lines. MITD1 silencing distinctly diminished CC cell viability, increased CC cell ferroptosis and attenuated their invasion and migration abilities. In addition, MITD1 knockdown significantly increased the expression of lipid ROS and total iron levels in CC cells. Additionally, the results showed that SRSF1 could stabilize MITD1 mRNA expression in CC cells. Finally, it was revealed that SRSF1 could regulate MITD1 and affect the progression of CC and ferroptosis via p53/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling. Overall, the results of the current study indicated that SRSF1-regulated MITD1 could affect CC progression and ferroptosis, probably via the p53/SLC7A11/GPX4 signaling pathway.

PABPN1 functions as a predictive biomarker in colorectal carcinoma

PURPOSE

PABPN1 acts as a modulator of poly(A) tail length and alternative polyadenylation. This research was aimed to explore the role of PABPN1 in colorectal cancer (CRC).

METHODS

Public databases were performed to analyze expression, location, roles of prognosis and tumor immunity and interaction with RNAs and proteins of PABPN1. To investigate PABPN1 expression in tissues, 78 CRC specimens were collected to conduct IHC, and 30 pairs of frozen CRC and corresponding adjacent normal tissues were used to conduct qRT-PCR and WB. In addition, in vitro experiments were then carried out to identify the role of PABPN1 in CRC.

RESULTS

Compared with normal tissues, PABPN1 expression was significant higher in CRC. Its high level predicted poor outcome of CRC. Th1 and Treg had significant negative relationships not only with PABPN1 expression, but also with six molecules interacting with PABPN1, including IFT172, KIAA0895L, RECQL4, WDR6, PABPC1 and NCBP1. In addition, PABPN1 had negative relationships with quite a few immune markers, such as CSF1R, IL-10, CCL2 and so on. In cellular experiments, silencing PABPN1 inhibited proliferation and promoted apoptosis in HCT-116 CRC cells.

CONCLUSION

In summary, PABPN1 might become a novel biomarker and correlate with tumor immunity in CRC.

STAT3 as a newly emerging target in colorectal cancer therapy: Tumorigenesis, therapy response, and pharmacological/nanoplatform strategies

Colorectal cancer (CRC) ranks as the third most aggressive tumor globally, and it can be categorized into two forms: colitis-mediated CRC and sporadic CRC. The therapeutic approaches for CRC encompass surgical intervention, chemotherapy, and radiotherapy. However, even with the implementation of these techniques, the 5-year survival rate for metastatic CRC remains at a mere 12-14%. In the realm of CRC treatment, gene therapy has emerged as a novel therapeutic approach. Among the crucial molecular pathways that govern tumorigenesis, STAT3 plays a significant role. This pathway is subject to regulation by cytokines and growth factors. Once translocated into the nucleus, STAT3 influences the expression levels of factors associated with cell proliferation and metastasis. Literature suggests that the upregulation of STAT3 expression is observed as CRC cells progress towards metastatic stages. Consequently, elevated STAT3 levels serve as a significant determinant of poor prognosis and can be utilized as a diagnostic factor for cancer patients. The biological and malignant characteristics of CRC cells contribute to low survival rates in patients, as the upregulation of STAT3 prevents apoptosis and promotes pro-survival autophagy, thereby accelerating tumorigenesis. Furthermore, STAT3 plays a role in facilitating the proliferation of CRC cells through the stimulation of glycolysis and promoting metastasis via the induction of epithelial-mesenchymal transition (EMT). Notably, an intriguing observation is that the upregulation of STAT3 can mediate resistance to 5-fluorouracil, oxaliplatin, and other anti-cancer drugs. Moreover, the radio-sensitivity of CRC diminishes with increased STAT3 expression. Compounds such as curcumin, epigallocatechin gallate, and other anti-tumor agents exhibit the ability to suppress STAT3 and its associated pathways, thereby impeding tumorigenesis in CRC. Furthermore, it is worth noting that nanostructures have demonstrated anti-proliferative and anti-metastatic properties in CRC.

SRSF1 induces glioma progression and has a potential diagnostic application in grading primary glioma

Glioma is the most common intracranial tumor of the central nervous system in adults; however, the diagnosis of glioma, and its grading and histological subtyping, is challenging for pathologists. The present study assessed serine and arginine rich splicing factor 1 (SRSF1) expression in 224 glioma cases in the Chinese Glioma Genome Atlas (CGGA) database, and verified its expression by immunohistochemical analysis of specimens from 70 clinical patients. In addition, the prognostic potential of SRSF1 concerning the survival status of patients was evaluated. In vitro, the biological role of SRSF1 was assessed using MTT, colony formation, wound healing and Transwell assays. The results revealed that SRSF1 expression was significantly associated with the grading and the histopathological subtype of glioma. As determined using a receiver operating characteristic curve analysis, the specificity of SRSF1 for glioblastoma (GBM) and World Health Organization (WHO) grade 3 astrocytoma was 40 and 48%, respectively, whereas the sensitivity was 100 and 85%. By contrast, pilocytic astrocytoma tumors exhibited negative immunoexpression of SRSF1. Additionally, Kaplan-Meier survival analysis indicated that high SRSF1 expression predicted a worse prognosis for patients with glioma in both the CGGA and clinical cohorts. In vitro, the results demonstrated that SRSF1 promoted the proliferation, invasion and migration of U87MG and U251 cells. These data suggested that immunohistochemical analysis of SRSF1 expression is highly sensitive and specific in the diagnosis of GBM and WHO grade 3 astrocytoma, and may have an important role in glioma grading. Furthermore, the lack of SRSF1 is a potential diagnostic biomarker for pilocytic astrocytoma. However, neither in oligodendroglioma and astrocytoma, nor in GBM was an association detected between SRSF1 expression and IDH1 mutations or 1p/19q co-deletion. These findings indicated that SRSF1 may serve as a prognostic factor in glioma cases and could have an active role in promoting glioma progression.

Highlighting functions of apoptosis and circular RNAs in colorectal cancer

Colorectal cancer (CRC) is known as one of the global problems that endangers the lives of thousands of people every year. Various treatments have been used to deal with this disease, but in some cases, they are not effective. Circular RNAs, as a novel class of noncoding RNAs, have different expression levels and various functions in cancer cells, such as gene regulation through microRNA sponging. They play an important role in various cellular processes, including differentiation, proliferation, invasion, and apoptosis. Changes in the process of apoptosis are closely related to the progression or inhibition of various malignancies. Induction of apoptosis in cancer cells is a promising target for tumor therapy. In this study, circRNAs were investigated as being central to the induction or inhibition of apoptosis in CRC. It is hoped that through targeted changes in the function of these biomolecules, better outcomes will be achieved in cancer treatment. Perhaps better outcomes for cancer treatment can be achieved by using new methods and modifying the expression of these nucleic acids. However, using this method may come with challenges and limitations.

Propofol Suppresses Glioma Tumorigenesis by Regulating circ_0047688/miR-516b-5p/IFI30 Axis

Propofol has recently attracted increasing attention for its anti-tumor property in cancers, including glioma. Circular RNAs (circRNAs) can act as key regulators in various cancers. However, the relationship between propofol and circ_0047688 in glioma is still unclear. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and colony formation assays. Cell migration and invasion were determined using transwell assay. Cell apoptosis was detected by flow cytometry. Protein levels and RNA levels were detected by western blot assay and real-time quantitative polymerase chain reaction (RT‑qPCR), respectively. The intermolecular interaction was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay. A mouse xenograft model was established for in vivo experiments. Propofol inhibited cell proliferation, migration, and invasion and accelerated apoptosis in glioma cells. Circ_0047688 was upregulated in glioma tissues and cells, and propofol downregulated circ_0047688 in a dose-dependent manner. Circ_0047688 knockdown inhibited glioma cell progression and its overexpression abated the anti-tumor role of propofol in glioma cells. Moreover, miR-516b-5p was a direct target of circ_0047688, and circ_0047688 promoted glioma cell progression by sponging miR-516b-5p. In addition, IFI30 was a direct target of miR-516b-5p, and miR-516b-5p inhibited glioma cell malignant behaviors by targeting IFI30 in propofol-treated cells. Furthermore, circ_0047688 overexpression could weaken the anti-tumor role of propofol in vivo. Propofol inhibited glioma progression via modulating circ_0047688/miR-516b-5p/IFI30 axis, providing a potential therapeutic strategy for treatment of glioma.

Propofol Regulates ER Stress to Inhibit Tumour Growth and Sensitize Osteosarcoma to Doxorubicin

Osteosarcoma is the most common malignant bone tumour affecting children and young adults. The antitumour role of propofol, a widely used intravenous sedative-hypnotic agent, has been recently reported in different cancer types. In this study, we aimed to assess the role of propofol on osteosarcoma and explore the possible mechanisms. Propofol of increasing concentrations (2.5, 5, 10, and 20 μg/ml) was used to treat the MG63 and 143B cells for 72 hours, and the CCK8 assay was applied to evaluate the tumour cell proliferation. Tumour cell migration and invasion were assessed with the transwell assay. The tumour cells were also treated with doxorubicin single agent or in combination with propofol to explore their synergic role. Differential expressed genes after propofol treatment were obtained and functionally assessed with bioinformatic tools. Expression of ER stress markers CHOP, p-eIF2α, and XBP1s was evaluated to validate the activation of ER stress response with western blot and qRT-PCR. The statistical analyses were performed with R v4.2.1. Propofol treatment led to significant growth inhibition in MG63 and 143B cells in a dose-dependent manner (p < 0.05). Osteosarcoma migration (MG63 91.4 (82-102) vs. 56.8 (49-65), p < 0.05; 143B 96.6 (77-104) vs. 45.4 (28-54), p < 0.05) and invasion (MG63 68.6 (61-80) vs. 32 (25-39), p < 0.05; 143B 90.6 (72-100) vs. 39.2 (26-55), p < 0.05) were reduced after propofol treatment. Doxorubicin sensitivity was increased after propofol treatment compared with the control group (p < 0.05). Bioinformatic analysis showed significant functional enrichment in ER stress response after propofol treatment. Upregulation of CHOP, p-eIF2α, and XBP1s was detected in MG63 and 143B secondary to propofol treatment. In conclusion, we found that propofol treatment suppressed osteosarcoma proliferation and invasion and had a synergic role with doxorubicin by inducing ER stress. Our findings provided a novel option in osteosarcoma therapy.

Etomidate elicits anti-tumor capacity by disrupting the JAK2/STAT3 signaling pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading malignancy of the digestive system, especially in China. Although radiotherapy, chemotherapy, and transarterial chemoembolization have achieved tremendous success, surgical resection remains the primary treatment for HCC patients. Recent studies have shown that intravenous anesthetic drugs may affect the malignant behaviors of tumor cells, ultimately leading to differences in the postoperative prognosis of patients. Etomidate is one of the most widely used intravenous anesthetic drugs for the induction and maintenance of anesthesia in tumor patients undergoing surgery. However, the effects and underlying mechanisms of etomidate on HCC cells have not yet been characterized. Our study indicated that etomidate significantly impedes the malignant progression of HCC cells. Mechanistically, etomidate inhibits phosphorylation and, ultimately, the activity of Janus kinase 2 (JAK2) by competing with ATP for binding to the ATP-binding pocket of JAK2. Thus, it suppresses the JAK2/STAT3 signaling pathway in HCC cells to exert its anti-tumor efficacy. Herein, we provide preclinical evidence that etomidate is the optimal choice for surgical treatment of HCC patients.

Exosomal circPRRX1 functions as a ceRNA for miR-596 to promote the proliferation, migration, invasion, and reduce radiation sensitivity of gastric cancer cells via the upregulation of NF-κB activating protein

Exosomes, which are small extracellular vesicles, have been unveiled to carry circular RNAs (circRNAs). CircRNA paired-related homeobox 1 (circPRRX1) can be transferred by exosomes derived from gastric cancer cells. Here, we investigated the activity and mechanism of exosomal circPRRX1 in gastric tumorigenesis and radiation sensitivity. CircPRRX1, microRNA (miR)-596, and NF-κB activating protein (NKAP) were quantified by quantitative real-time PCR and immunoblotting. Cell proliferation, motility, and invasion were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and transwell assays, respectively. Cell colony formation and survival were assessed by colony formation assays. Dual-luciferase reporter assays were performed to verify the direct relationship between miR-596 and circPRRX1 or NKAP. In-vivo xenograft studies were used to evaluate the role of exosomal circPRRX1 in tumor growth. Our data showed that circPRRX1 expression was elevated in human gastric cancer, and circPRRX1 could be transferred by exosomes from gastric cancer cells. Exosomal circPRRX1 affected cell proliferation, motility, invasion, and radiation sensitivity in vitro and tumor growth in vivo. Mechanistically, circPRRX1 directly regulated miR-596 expression, and exosomal circPRRX1 affected cell biological functions at least in part through miR-596. NKAP was identified as a direct target and functionally downstream effector of miR-596. Exosomal circPRRX1 modulated NKAP expression by acting as a competing endogenous RNA (ceRNA) for miR-596. Our findings suggest a new mechanism, the exosomal circPRRX1/miR-596/NKAP ceRNA crosstalk, in regulating gastric tumorigenesis and radiation sensitivity.

Gene expression analysis reveals a 5-gene signature for progression-free survival in prostate cancer

Prostate cancer (PCa) is the second most common male cancer worldwide, but effective biomarkers for the presence or progression risk of disease are currently elusive. In a series of nine matched histologically confirmed PCa and benign samples, we carried out an integrated transcriptome-wide gene expression analysis, including differential gene expression analysis and weighted gene co-expression network analysis (WGCNA), which identified a set of potential gene markers highly associated with tumour status (malignant vs. benign). We then used these genes to establish a minimal progression-free survival (PFS)-associated gene signature (GS) (PCBP1, PABPN1, PTPRF, DANCR, and MYC) using least absolute shrinkage and selection operator (LASSO) and stepwise multivariate Cox regression analyses from The Cancer Genome Atlas prostate adenocarcinoma (TCGA-PRAD) dataset. Our signature was able to predict PFS over 1, 3, and 5 years in TCGA-PRAD dataset, with area under the curve (AUC) of 0.64–0.78, and our signature remained as a prognostic factor independent of age, Gleason score, and pathological T and N stages. A nomogram combining the signature and Gleason score demonstrated improved predictive capability for PFS (AUC: 0.71–0.85) and was superior to the Cambridge Prognostic Group (CPG) model alone and some conventionally used clinicopathological factors in predicting PFS. In conclusion, we have identified and validated a novel five-gene signature and established a nomogram that effectively predicted PFS in patients with PCa. Findings may improve current prognosis tools for PFS and contribute to clinical decision-making in PCa treatment.

Propofol Augments Paclitaxel-Induced Cervical Cancer Cell Ferroptosis In Vitro

Introduction: Cervical cancer is common in women. The present standardized therapies including surgery, chemotherapy, and radiotherapy are still not enough for treatment. Propofol is the most commonly used intravenous anesthetic agent for induction and maintenance of anesthesia and has been shown to exert anti-malignancy effects on cancer cells, inducing oxidative stress and apoptosis. However, the biological effects of propofol have not yet been systematically assessed. In this study, we examined the ferroptosis-related changes caused by propofol and the chemotherapeutic agent paclitaxel besides apoptosis in vitro.

Methods: Cervical cancer cell lines (C-33A and HeLa) were treated with propofol alone (1, 2, 5, 10, and 20 μg/ml) or in combination with paclitaxel (0.5, 1, and 5 μg/ml). The viability was assessed using cell counting kit-8 (CCK8), apoptosis was detected by flow cytometry, morphological changes of mitochondria were examined using transmission electron microscope (TEM), cellular reactive oxygen species (ROS), and intracellular ferrous ions were determined by fluorescence microscope or confocal microscopy. The expression and cellular localization of apoptosis and ferroptosis-related molecules were detected by Western blot and multiplex immunohistochemistry (mIHC), respectively. Calcusyn software was used to determine whether propofol has a synergistic effect with paclitaxel.

Results: Propofol and paclitaxel inhibited C-33A and HeLa cell viability. There were also synergistic effects when propofol and paclitaxel were used in combination at certain concentrations. In addition, propofol promoted paclitaxel-induced cervical cancer cell death via apoptosis. ROS level and Fe²⁺ concentrations were also influenced by different drug treatments. Furthermore, propofol, propofol injectable emulsion, and paclitaxel induced ferroptosis-related morphological changes of mitochondria in C-33A and HeLa cells. Ferroptosis-related signaling pathways including SLC7A11/GPX4, ubiquinol/CoQ10/FSP1, and YAP/ACSL4/TFRC were found to be changed under drug treatments.

Conclusion: Propofol showed synergistic anticancer effects with paclitaxel in cervical cancer cells. Propofol and paclitaxel may induce ferroptosis of cervical cancer cells besides apoptosis.