STAT3 inhibitor BBI608 reduces patient-specific primary cell viability of cervical and endometrial cancer at a clinical-relevant concentration

Expression levels of STAT3, and protein levels of IL‑6 and sPD‑L1 in different pathological characteristics of endometrial adenocarcinomas

Endometrial cancer is a common type of cancer in women, with endometrial adenocarcinoma (EA) being the most common type. Monitoring the expression levels of signal transducer and activator of transcription 3 (STAT3), the protein levels of interleukin 6 (IL-6) and soluble programmed death ligand 1 (sPD-L1), and their differences in patients with various pathological characteristics is beneficial for accurately evaluating the disease stage and differentiation degree of patients in clinical practice. The aim of the present study was to assess the expression levels of STAT3, and the protein levels of IL-6 and sPD-L1 in EA. In the present retrospective study, data were retrieved from the medical records of 137 patients with EA who received surgical treatment at The First Affiliated Hospital of Hebei North University from January 2017 to December 2022. Of the 137 cases, 90 met the inclusion criteria. The patients with EA were matched with a cohort of 30 patients with atypical endometrial hyperplasia in a ratio of 3:1. Among the 90 patients with EA, 30 patients with well-differentiated EA were matched with 30 patients with moderately differentiated EA and 30 patients with poorly differentiated EA in a 1:1:1 ratio. Expression level of STAT3, and protein levels of IL-6 and sPD-L1 were recorded preoperatively and compared between patients with different pathological characteristics [such as differentiation degree, disease stage, depth of myometrial invasion and lymph node metastasis (LNM)] and prognosis. Levels of IL-6, STAT3 and sPD-L1 in the observation group were significantly higher compared with the control group (P<0.001). Additionally, there were significant differences in IL-6, STAT3 and sPD-L1 levels between patients with different differentiation degrees, disease stages, myometrial invasion and LNM (P<0.001). The increase in IL-6, STAT3 and sPD-L1 levels were significantly associated with the decrease in the differentiation degree and the increase in the disease stage, depth of myometrial invasion and LNM (P<0.001). IL-6, STAT3 and sPD-L1 levels in patients with a poor prognosis were significantly higher compared with patients with good prognoses (P<0.001). Overall, the expression levels of STAT3, and the protein levels of IL-6 and sPD-L1 were increased in patients with EA compared with in those without EA, and their increase is associated with the pathological characteristics of the disease. The levels of these indices may be detected in clinical practices to evaluate the disease and predict the prognosis.

Structure, function, signaling pathways and clinical therapeutics: The translational potential of STAT3 as a target for cancer therapy

Cancer remains one of the most difficult human diseases to overcome because of its complexity and diversity. Signal transducers and transcriptional activators 3 (STAT3) protein has been found to be overexpressed in a wide range of cancer types. Hyperactivation of STAT3 is particularly associated with low survival in cancer patients. This review summarizes the specific molecular mechanisms of STAT3 in cancer development. STAT3 is activated by extracellular signals in the cytoplasm, interacts with different enzymes in the nucleus, mitochondria or endoplasmic reticulum, and subsequently participates in cancer development. The phosphorylated STAT3 at tyrosine 705 site (YP-STAT3) enters the nucleus and regulates a number of tumor-related biological processes such as angiogenesis, migration invasion, cell proliferation and cancer cell stemness. In contrast, the phosphorylated STAT3 at serine 727 site (SP-STAT3) is found on the mitochondria, affects electron respiration transport chain activity and thereby prevents tumor cell apoptosis. SP-STAT3 also appears on the mitochondria-associated endoplasmic reticulum membrane, influences the flow of Ca2+, and affects tumor progression. In addition, we summarize the direct and indirect inhibitors of STAT3 which are currently undergoing clinical studies. Some of them such as TTI101 and BBI608 have been approved by the FDA for the treatment of certain cancers. All in all, STAT3 plays an important role in cancer progression and becomes a potential target for cancer treatment.

TTI-101 targets STAT3/c-Myc signaling pathway to suppress cervical cancer progression: an integrated experimental and computational analysis

BACKGROUND

Cervical cancer (CC) is a significant global health concern, demanding the consideration of novel therapeutic strategies. The signal transducer and activator of transcription 3 (STAT3) pathway has been implicated in cancer progression and is a potential target for therapeutic intervention. This study aimed to explore the therapeutic potential of TTI-101, a small molecule STAT3 inhibitor, in CC and investigate its underlying mechanisms.

METHODS

Molecular docking studies and molecular dynamics simulations were performed to explore the binding interaction between TTI-101 and STAT3 and assess the stability of the STAT3-TTI-101 complex. Cell viability assays, wound healing assays, colony formation assays, flow cytometry analysis, and gene expression analysis were conducted. In vivo xenograft models were used to assess the antitumor efficacy of TTI-101.

RESULTS

The in silico analysis shows a stable binding interaction between TTI-101 and STAT3. TTI-101 treatment inhibits cell viability, clonogenic ability, and cell migration in CC cells. Furthermore, TTI-101 induces apoptosis and cell cycle arrest. Analysis of apoptosis-related markers demonstrated dysregulation of Bax, Bcl-2, and Caspase-3 upon TTI-101 treatment. Moreover, TTI-101 caused G2/M phase arrest accompanied by a decrease in CDK1 and Cyclin B1 at mRNA levels. In the xenograft model, TTI-101 significantly inhibited tumor growth without adverse effects on body weight.

CONCLUSION

TTI-101 exhibited anticancer effects by targeting the STAT3/c-Myc signaling pathway, inducing cell cycle arrest, and promoting apoptosis in CC cells. These findings provide valuable insights into the development of novel therapeutic strategies for cervical cancer. Further investigation is warranted to validate the clinical application of TTI-101.

The role of ncRNAs and exosomes in the development and progression of endometrial cancer

Endometrial cancer (EC) is one of the most common gynecologic cancers. In recent years, research has focused on the genetic characteristics of the tumors to detail their prognosis and tailor therapy. In the case of EC, genetic mutations have been shown to underlie their formation. It is very important to know the mechanisms of EC formation related to mutations induced by estrogen, among other things. Noncoding RNAs (ncRNAs), composed of nucleotide transcripts with very low protein-coding capacity, are proving to be important. Their expression patterns in many malignancies can inhibit tumor formation and progression. They also regulate protein coding at the epigenetic, transcriptional, and posttranscriptional levels. MicroRNAs (miRNAs), several varieties of which are associated with normal endometrium as well as its tumor, also play a particularly important role in gene expression. MiRNAs and long noncoding RNAs (lncRNAs) affect many pathways in EC tissues and play important roles in cancer development, invasion, and metastasis, as well as resistance to anticancer drugs through mechanisms such as suppression of apoptosis and progression of cancer stem cells. It is also worth noting that miRNAs are highly precise, sensitive, and robust, making them potential markers for diagnosing gynecologic cancers and their progression. Unfortunately, as the incidence of EC increases, treatment becomes challenging and is limited to invasive tools. The prospect of using microRNAs as potential candidates for diagnostic and therapeutic use in EC seems promising. Exosomes are extracellular vesicles that are released from many types of cells, including cancer cells. They contain proteins, DNA, and various types of RNA, such as miRNAs. The noncoding RNA components of exosomes vary widely, depending on the physiology of the tumor tissue and the cells from which they originate. Exosomes contain both DNA and RNA and have communication functions between cells. Exosomal miRNAs mediate communication between EC cells, tumor-associated fibroblasts (CAFs), and tumor-associated macrophages (TAMs) and play a key role in tumor cell proliferation and tumor microenvironment formation. Oncogenes carried by tumor exosomes induce malignant transformation of target cells. During the synthesis of exosomes, various factors, such as genetic and proteomic data are upregulated. Thus, they are considered an interesting therapeutic target for the diagnosis and prognosis of endometrial cancer by analyzing biomarkers contained in exosomes. Expression of miRNAs, particularly miR-15a-5p, was elevated in exosomes derived from the plasma of EC patients. This may suggest the important utility of this biomarker in the diagnosis of EC. In recent years, researchers have become interested in the topic of prognostic markers for EC, as there are still too few identified markers to support the limited treatment of endometrial cancer. Further research into the effects of ncRNAs and exosomes on EC may allow for cancer treatment breakthroughs.

Prognostic and therapeutic potential of STAT3: Opportunities and challenges in targeting HPV-mediated cervical carcinogenesis

Cervical cancer (CaCx) ranks as the fourth most prevalent cancer among women globally. Persistent infection of high-risk human papillomaviruses (HR-HPVs) is major etiological factor associated with CaCx. Signal Transducer and Activator of Transcription 3 (STAT3), a prominent member of the STAT family, has emerged as independent oncogenic driver. It is a target of many oncogenic viruses including HPV. How STAT3 influences HPV viral gene expression or gets affected by HPV is an area of active investigation. A better understanding of host-virus interaction will provide a prognostic and therapeutic window for CaCx control and management. In this comprehensive review, we delve into carcinogenic role of STAT3 in development of HPV-induced CaCx. With an emphasis on fascinating interplay between STAT3 and HPV genome, the review explores the diverse array of opportunities and challenges associated with this field to harness the prognostic and therapeutic potential of STAT3 in CaCx.

Induction of ferroptosis and apoptosis in endometrial cancer cells by dihydroisotanshinone I

Danshen, also known as Salvia miltiorrhiza, is a medicinal herb used in traditional Chinese medicine. Its potential impact on endometrial cancer has not been thoroughly investigated. This study aimed to examine the effect of dihydroisotanshinone I (DT), a compound found in Danshen, on the viability of ARK1 and ARK2 endometrial cancer cells and its mechanisms. The results showed that 10 μM DT inhibited cell viability of ARK1 and ARK2 cells by inducing apoptosis and ferroptosis, which was achieved by blocking the expression of GPX4. In vivo experiments using a xenograft nude mouse model indicated that DT treatment significantly reduced tumor volume without causing any adverse effects. These findings suggest that DT may be a potential therapeutic agent for inhibiting endometrial cancer cell viability, but further research is needed to confirm these results.

An Isoxazoloquinone Derivative Inhibits Tumor Growth by Targeting STAT3 and Triggering Its Ubiquitin-Dependent Degradation

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with shorter five-year survival than other breast cancer subtypes, and lacks targeted and hormonal treatment strategies. The signal transducer and activator of transcription 3 (STAT3) signaling is up-regulated in various tumors, including TNBC, and plays a vital role in regulating the expression of multiple proliferation- and apoptosis-related genes.

RESULTS

By combining the unique structures of the natural compounds STA-21 and Aulosirazole with antitumor activities, we synthesized a class of novel isoxazoloquinone derivatives and showed that one of these compounds, ZSW, binds to the SH2 domain of STAT3, leading to decreased STAT3 expression and activation in TNBC cells. Furthermore, ZSW promotes STAT3 ubiquitination, inhibits the proliferation of TNBC cells in vitro, and attenuates tumor growth with manageable toxicities in vivo. ZSW also decreases the mammosphere formation of breast cancer stem cells (BCSCs) by inhibiting STAT3.

CONCLUSIONS

We conclude that the novel isoxazoloquinone ZSW may be developed as a cancer therapeutic because it targets STAT3, thereby inhibiting the stemness of cancer cells.