Previously, we identified that AP-1 transcription factor FOSL1 is required to maintain cancer stem cells (CSCs) in HNSCC, and an AP-1 inhibitor, T-5224, can eliminate HNSCC CSCs. However, its potency is relatively low, and furthermore, whether T-5224 eradicates CSCs through targeting FOSL1 and whether FOSL1 serves as an effective target for eliminating CSCs in HNSCC, require further validation. We first found that T-5224 can bind to FOSL1 directly. As a proof-of-principle, several cereblon (CRBN)-recruiting PROTACs were designed and synthesized using T-5224 as a warhead for more effective of targeting FOSL1. The top compound can potently degrade FOSL1 in HNSCC, thereby effectively eliminating CSCs to suppress HNSCC tumorigenesis, with around 30 to 100-fold improved potency over T-5224. In summary, our study further validates FOSL1 as an effective target for eliminating CSCs in HNSCC and suggests that PROTACs may provide a unique molecular tool for the development of novel molecules for targeting FOSL1.

Over the past 20 years, increasing evidence has demonstrated that immunoglobulins (Igs) can be widely generated from non B cells, including normal and malignant mammary epithelial cells. In normal breast tissue, the expression of IgG and IgA has been identified in epithelial cells of mammary glands during pregnancy and lactation, which can be secreted into milk, and might participate in neonatal immunity. On the other hand, non B-IgG is highly expressed in breast cancer cells, correlating with the poor prognosis of patients with breast cancer. Importantly, a specific group of IgG, bearing a unique N-linked glycan on the Asn162 site and aberrant sialylation modification at the end of the novel glycan (referred to as sialylated IgG (SIA-IgG)), has been found in breast cancer stem/progenitor-like cells. SIA-IgG can significantly promote the capacity of migration, invasiveness, and metastasis, as well as enhance self-renewal and tumorigenicity in vitro and in vivo. These findings suggest that breast epithelial cells can produce Igs with different biological activities under physiological and pathological conditions. During lactation, these Igs could be the main source of milk Igs to protect newborns from pathogenic infections, while under pathological conditions, they display oncogenic activity and promote the occurrence and progression of breast cancer.

A cancer mass is composed of a heterogeneous group of cells, a small part of which constitutes the cancer stem cells since they are less differentiated and have a high capacity to develop cancer. Versican is an extracellular matrix protein located in many human tissues. The mRNA of versican has been shown to have \"splicing patterns\" as detected by RT-PCR, northern blot analysis, and cDNA sequencing. Based on this knowledge this study aims to reveal the splice variants of versican molecules, which are thought to be involved in the pathogenesis of the DU-145 human prostatic carcinoma cell line and prostatic cancer stem cells isolated from this cell line. In this study, RWPE-1 normal prostatic and DU-145 human prostate cancer cell lines have been used. Prostatic cancer stem cells and the remaining group of non-prostatic-cancer stem cells (bulk population) were isolated according to their CD133+/CD44+. RNA was isolated in all groups, and sequence analysis was accomplished for splicing variants by Illumina NextSeq 500 sequencing system. The results were analyzed by bioinformatic evaluation. As five isoforms of the versican gene in the differential transcript expression are analyzed, it was observed that a significant change was only found in the isoforms Versican 0 and Versican 1. In this study, we explored the function of this molecule which we think to be effective in cancer progression, and suggested that more valuable results can be obtained after the accomplishment of in vivo experiments.

Coregulation of microRNAs (miRNAs) and cancer stem cells (CSCs) is very important in carcinogenesis. miR-127-5p is known to be downregulated in breast cancer. In this study, we aimed to investigate how boric acid (BA), known for its previously unstudied anti-cancer properties, would affect the expression of miR127-5p and genes responsible for breast cancer stem cells (BC-SCs) metastasis. BC-SCs were isolated from human breast cancer cells (MCF-7) by immunomagnetic cell separation and characterized with flow cytometry and sphere formation. The viability of BC-SCs and the determination of its IC50 value in response to boric acid (BA) were assessed via the MTT assay. Boric acid exhibited dose- and time-dependent inhibition of cell viability in cells. The IC50 doses of boric acid in MCF-7 cells and BC-SCs were 45.69 mM and 41.27 mM, respectively. The impact of BA on the expression of metastatic genes and miR127-5p was elucidated through RT-qPCR analysis. While the expression of the COL1A1 (p < 0.05) and VIM (p < 0.01) was downregulated, the expression of the miR-127-5p, ZEB1 (p < 0.01), CDH1 (p < 0.05), ITGB1 (p < 0.05), ITGA5 (p < 0.05), LAMA5 (p < 0.01), and SNAIL (p < 0.05), was up-regulated in dose-treated BC-SCs (p < 0.001) to the RT-qPCR results. Our findings suggest that boric acid could induce miR-127-5p expression. However, it cannot be said that it improves the metastasis properties of breast cancer stem cells.

Placenta-specific protein 1 (PLAC-1) is a gene primarily expressed in the placenta and the testis. Interestingly, it is also found to be expressed in many solid tumors, and it is involved in malignant cell features. However, no evidence has been reported regarding the relationship between PLAC-1 and cancer stem cells (CSCs). In the current research, we explored the expression of the PLAC-1 molecule in prostate cancer stem cells (PCSCs) derived from the human PC-3 cell line. The enrichment of PCSCs was achieved using a three-dimensional cell culture technique known as the sphere-formation assay. To confirm the identity of PCSCs, we examined the expression of genes associated with stemness and pluripotency, such as SOX2, OCT4, Nanog, C-Myc, and KLF-4, as well as stem cell differentiation molecules like CD44 and CD133. These evaluations were conducted in both the PCSCs and the original tumor cells (parental cells) using real-time PCR and flow cytometry. Subsequently, we assessed the expression of the PLAC-1 molecule in both enriched cells and parental tumor cells at the gene and protein levels using the same techniques. The tumor cells from the PC-3 cell line formed spheroids with CSC characteristics in a non-adherent medium. The expression of SOX2, OCT4, Nanog, and C-Myc genes (p < 0.01), and the molecules CD44 and CD133 (p < 0.05) were significantly elevated in PCSCs compared to the parental cells. The expression of the PLAC-1 molecule in PCSCs showed a significant increase compared to the parental cells at both gene (p < 0.01) and protein (p < 0.001) levels. In conclusion, it was indicated for the first time that PLAC-1 is up-regulated in PCSCs derived from human PC-3 cell line. This study may propose PLAC-1 as a potential target in targeted therapies, which should be confirmed through further studies.

A \"Think Tank for Osteosarcoma\" medical advisory board meeting was held in Santa Monica, CA, USA on February 2-3, 2024. The goal was to develop a strategic approach to prevent recurrence of osteosarcoma. Osteosarcoma metabolism and the genomic instability of osteosarcoma, immunotherapy for osteosarcoma, CAR-T cell therapy, DeltaRex-G tumor-targeted gene therapy, repurposed drugs, alternative medicines, and personalized medicine were discussed. Only DeltaRex-G was voted on. The conclusions were the following: No intervention has been demonstrated to improve survival in a clinical trial. Additionally, the consensus (10/12 in favor) was that DeltaRex-G without immunotherapy may be administered for up to one year. Phase 2/3 randomized studies of DeltaRex-G should be performed to determine whether the incidence of recurrence could be reduced in high-risk individuals. Furthermore, a personalized approach using drugs with minimal toxicity could be attempted with the acknowledgement that there are no efficacy data to base this on. Repurposed drugs and alternative therapies should be tested in mouse models of osteosarcoma. Moreover, unmodified IL-2 primed Gamma Delta (NK) cell therapy may be used to prevent recurrence. Lastly, rapid development of CAR-T cell therapy is recommended, and an institute dedicated to the study of osteosarcoma is needed.

UNASSIGNED: Cancer stem cells (CSCs) substantially influence the development of colorectal cancer (CRC), metastasis, relapse, and resistance to therapy. Ibuprofen and hyperthermia can be effective in the treatment of cancer. Herein, we evaluated the effects of hyperthermia and ibuprofen on the isolated-CSCs of CRC.
UNASSIGNED: This experimental study was conducted between Sep 2020 and Jan 2022 at the Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Iran. A non-adhesive culture system was used to isolate CSCs from HT-29 cells. To confirm the stemness nature of isolated-CSCs, the expression of stemness genes and protein markers was evaluated by quantitative Real-time PCR (qRT-PCR) and flow cytometry assay. The isolated-CSCs were treated with hyperthermia and ibuprofen. The cell viability was determined by MTT assay and trypan blue staining. The expression of stemness, proliferation, Wnt signaling pathway and apoptosis genes was assessed by qRT-PCR.
UNASSIGNED: CSCs were isolated within 14 days. The expression of CD-133 marker and OCT3/4, C-MYC, KLF4, and NANOG genes in isolated-CSCs was higher than HT-29 cells (P<0.05). Cell viability of treated-CSCs were considerably reduced (P<0.05). Hperthermia reduced the expression of OCT3/4, NANOG, PCNA, WNT1 and CTNNB1 genes and increased the expression of P53, BAX, and KLF4 genes (P<0.05). Ibuprofen decreased the expression of OCT3/4, BCL2, NANOG, PCNA, WNT1, and CTNNB1 genes and increased the expression of P53, BAX, and KLF4 genes in treated-CSCs (P<0.05).
UNASSIGNED: Hyperthermia and ibuprofen treatment demonstrate an inhibitory effect on colorectal CSCs. However, using combination therapy is remaining to be tested.

Background: Long non-coding RNAs (lncRNAs) are associated with multiple head and neck tumors and play important roles in cancer. This study explored the molecular mechanism of Linc00662 in hypopharyngeal squamous cell carcinoma (HSCC). Methods: Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect gene expression in HSCC tissues. The viability and proliferation of tumor cells were measured using CCK-8 assays. HSCC cell apoptosis was measured using flow cytometry and western blotting. Cell stemness was examined using the sphere formation assay. A xenograft tumor model was established to investigate the role of Linc00662 in vivo. Results: The expression level of Linc00662 in HSCC tissues was significantly higher than that in adjacent normal tissues. The expression of Linc00662 had no significant relationship with the tumor stage. Patients with high Linc00662 expression were found to have shorter overall survival than those with low Linc00662 expression. Linc00662 over-expression promoted cell viability and inhibited apoptosis. Using online databases and a dual luciferase reporter, miR-15b-5p was confirmed as a potential downstream sponge of Linc00662. Moreover, Linc00662 was negatively associated with miR-15b-5p in HSCC cells. Depletion of miR-15b-5p can reverse the function of Linc00662 in vivo and in vitro. Furthermore, Linc00662 promotes tumor growth, which was abolished by miR-15b-5p mimics. Importantly, the stemness of cancer stem cells was mediated by the Linc00662/miR-15b-5p axis. Conclusion: Patients with HSCC with high Linc00662 showed poor prognosis and high Linc00662 induced stemness of tumor cells by targeting miR-15b-5p. Linc00662 may serve as a novel diagnostic and target marker for head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) represents the predominant malignancies in the head and neck region, and has limited therapeutic alternatives. Circular RNAs (circRNAs), a substantial category of non-coding RNA molecules, exert influential roles in human disease development and progression, employing various mechanisms such as microRNA sponging, interaction with RNA-binding proteins, and translational capabilities. Accumulating evidence highlights the differential expression of numerous circRNAs in HNSCC, and numerous dysregulated circRNAs underscore their crucial involvement in malignant advancement and resistance to treatment. This review aims to comprehensively outline the characteristics, biogenesis, and mechanisms of circRNAs, elucidating their functional significance in HNSCC. In addition, we delve into the clinical implications of circRNAs, considering their potential as biomarkers or targets for diagnosis, prognosis, and therapeutic applications in HNSCC. The discussion extends to exploring future challenges in the clinical translation of circRNAs, emphasizing the need for further research.

The cancer stem cell (SC) theory proposes that a population of SCs serves as the driving force behind fundamental tumor processes, including metastasis, recurrence, and resistance to therapy. The standard of care for patients with stage III and high-risk stage II colorectal cancer (CRC) includes surgery and adjuvant chemotherapy. Fluoropyrimidines and their combination with oxaliplatin increased the cure rates, being able to eradicate the occult metastatic SC in a fraction of patients. The treatment for unresectable metastatic CRC is based on chemotherapy, antibodies to VEGF and EGFR, and tyrosine-kinase inhibitors. Immunotherapy is used in MSI-H tumors. Currently used drugs target dividing cells and, while often effective at debulking tumor mass, these agents have largely failed to cure metastatic disease. SCs are generated either due to genetic and epigenetic alterations in stem/progenitor cells or to the dedifferentiation of somatic cells where diverse signaling pathways such as Wnt/β-catenin, Hedgehog, Notch, TGF-β/SMAD, PI3K/Akt/mTOR, NF-κB, JAK/STAT, DNA damage response, and Hippo-YAP play a key role. Anti-neoplastic treatments could be improved by elimination of SCs, becoming an attractive target for the design of novel agents. Here, we present a review of clinical trials assessing the efficacy of targeted treatment focusing on these pathways in CRC.