Head and neck squamous cell carcinoma (HNSCC) is a major global health burden, often associated with poor prognosis and limited therapeutic options. Long non-coding RNAs (lncRNAs), a diverse group of non-coding RNA molecules > 200 nucleotides in length, have emerged as critical regulators in the pathogenesis of HNSCC. This review summarizes the mechanisms through which certain lncRNAs regulate chromatin modification, mRNA splicing, and interactions with RNA-binding proteins and contribute to the development and progression of HNSCC. Interaction of lncRNAs with key oncogenic pathways, such as PI3K/AKT and Wnt/β-catenin, highlights their importance in tumor progression. The role of lncRNAs, such as ELDR, MALAT1, NEAT1, HOTAIR, and UCA1, which promote cell proliferation, metastasis, immune evasion, and therapy resistance is discussed. Moreover, several lncRNAs are being evaluated in clinical trials for their potential as biomarkers, reflecting their clinical significance. We further address the challenges and opportunities for targeting lncRNA therapeutically, highlighting the promise of lncRNA-based interventions for personalized cancer treatment. Gaining insight into the function of lncRNAs in HNSCC could pave the way for novel therapeutic strategies to potentially improve patient outcomes.

TNBC patients respond poorly to chemotherapy, leading to high mortality rates and a worsening prognosis. Here, we investigated the effect of M-I on TNBC tumor growth suppression and its potential mechanisms. Signaling pathways were analyzed to study the effect of M-I on TNBC cells (human MDA-MB-231 and mouse 4T1). We used orthotopic mouse models to examine the anti-tumor efficacy of M-I. Tumor volume and the status of tumor-associated macrophages (TAMs) were assessed by qRT-PCR or FACS analysis. We found a significant dose- and time-dependent inhibition of TNBC cell proliferation following treatment with M-I. Cell cycle analysis revealed a shortened S phase in M-I-treated cells and downregulation of AURKA, PLK1, CDC25c, CDK1, and cyclinB1. Furthermore, M-I treatment reduced the expression of pSTAT3, cyclinD1, and c-Myc in TNBC cells. To evaluate the anti-tumor efficacy of M-I, we employed orthotopic TNBC mouse models and observed a significant reduction in tumor growth without measurable toxicity. Next, we analyzed RNA from control and M-I-treated tumors to further assess the status of TAMs and observed a significant decrease in M2-like macrophages in the M-I-treated group. Immortalized bone marrow-derived mouse macrophages (iMacs) exposed to conditioned media (CM) of TNBC cells with or without M-I treatment indicated that the M-I treated CM of TNBC cells significantly reduce the M2phenotype in iMacs. Mechanistically, we found that M-I specifically targets the IL-4/MAPK signaling axis to reduce immunosuppressive M2 macrophage polarization. Our study reveals a novel mechanism by which M-I inhibits TNBC cell proliferation by regulating intracellular signaling and altering TAMs in the tumor microenvironment and highlights its potential as a promising candidate for TNBC therapy.

[This retracts the article DOI: 10.1016/j.isci.2022.104325.].

The rising incidence of hepatocellular carcinoma (HCC) is a global problem. Several approved treatments, including immune therapy and multi-tyrosine kinase inhibitors, are used for treatment, although the results are not optimum. There is an unmet need to develop highly effective chemotherapies for HCC. Targeting multiple pathways to attack cancer cells is beneficial. Cabozantinib is an orally available bioactive multikinase inhibitor and has a modest effect on HCC treatment. Silmitasertib is an orally bioavailable, potent CK2 inhibitor with a direct role in DNA damage repair and is in clinical trials for other cancers. In this study, we planned to repurpose these existing drugs on HCC treatment. We observed a stronger antiproliferative effect of these two combined drugs on HCC cells generated from different etiologies as compared to the single treatment. Global RNA-seq analyses revealed a decrease in the expression of G2/M cell cycle transition genes in HCC cells following combination treatment, suggesting G2 phase cell arrest. We observed G2/M cell cycle phase arrest in HCC cells upon combination treatment compared to the single-treated or vehicle-treated control cells. The downregulation of CCNA2 and CDC25C following combination therapy further supported the observation. Subsequent analyses demonstrated that combination treatment inhibited 70 kDa ribosomal protein S6 kinase (p70S6K) phosphorylation, and increased Bim expression. Apoptosis of HCC cells were accompanied by increased poly (ADP-ribose) polymerase cleavage and caspase-9 activation. Next, we observed that a combination therapy significantly delayed the progression of HCC xenograft growth as compared to vehicle control. Together, our results suggested combining cabozantinib and silmitasertib would be a promising treatment option for HCC.

One of the hallmarks of cancer is metabolic reprogramming which controls cellular homeostasis and therapy resistance. Here, we investigated the effect of momordicine-I (M-I), a key bioactive compound from Momordica charantia (bitter melon), on metabolic pathways in human head and neck cancer (HNC) cells and a mouse HNC tumorigenicity model. We found that M-I treatment on HNC cells significantly reduced the expression of key glycolytic molecules, SLC2A1 (GLUT-1), HK1, PFKP, PDK3, PKM, and LDHA at the mRNA and protein levels. We further observed reduced lactate accumulation, suggesting glycolysis was perturbed in M-I treated HNC cells. Metabolomic analyses confirmed a marked reduction in glycolytic and TCA cycle metabolites in M-I-treated cells. M-I treatment significantly downregulated mRNA and protein expression of essential enzymes involved in de novo lipogenesis, including ACLY, ACC1, FASN, SREBP1, and SCD1. Using shotgun lipidomics, we found a significant increase in lysophosphatidylcholine and phosphatidylcholine loss in M-I treated cells. Subsequently, we observed dysregulation of mitochondrial membrane potential and significant reduction of mitochondrial oxygen consumption after M-I treatment. We further observed M-I treatment induced autophagy, activated AMPK and inhibited mTOR and Akt signaling pathways and leading to apoptosis. However, blocking autophagy did not rescue the M-I-mediated alterations in lipogenesis, suggesting an independent mechanism of action. M-I treated mouse HNC MOC2 cell tumors displayed reduced Hk1, Pdk3, Fasn, and Acly expression. In conclusion, our study revealed that M-I inhibits glycolysis, lipid metabolism, induces autophagy in HNC cells and reduces tumor volume in mice. Therefore, M-I-mediated metabolic reprogramming of HNC has the potential for important therapeutic implications.