Pharmacological restoration and therapeutic targeting of the B-cell phenotype in classical Hodgkin lymphoma

N6-methyladenine-mediated aberrant activation of the lncRNA SOX2OT-GLI1 loop promotes non-small-cell lung cancer stemness

Despite the advent of precision medicine and immunotherapy, mortality due to lung cancer remains high. The sonic hedgehog (SHH) cascade and its key terminal factor, glioma-associated oncogene homolog 1 (GLI1), play a pivotal role in the stemness and drug resistance of lung cancer. Here, we investigated the molecular mechanism of non-canonical aberrant GLI1 upregulation. The SHH cascade was upregulated in stem spheres and chemo-resistant lung cancer cells and was accountable for drug resistance against multiple chemotherapy regimens. GLI1 and the long non-coding RNA SOX2OT were positively regulated, and the GLI1-SOX2OT loop mediated the proliferation of parental and stem-like lung cancer cells. Further mechanistic investigation revealed that SOX2OT facilitated METTL3/14/IGF2BP2-mediated m6A modification and stabilization of the GLI1 mRNA. Additionally, SOX2OT upregulated METTL3/14/IGF2BP2 by sponging miR-186-5p. Functional analysis corroborated that GLI1 acted as a downstream target of METTL3/14/IGF2BP2, and GLI1 silencing could block the oncogenicity of lung cancer stem-like cells. Pharmacological inhibition of the loop remarkably inhibited the oncogenesis of lung cancer cells in vivo. Compared with paired adjacent normal tissues, lung cancer specimens exhibited consistently upregulated GLI1/SOX2OT/METTL3/14/IGF2BP2. The m6A-modified GLI1-SOX2OT loop may serve as a potential therapeutic target and prognostic predictor for lung cancer therapy and diagnosis in the clinic.

Advances in Hodgkin Lymphoma: Including the Patient's Voice

Since the initial treatment with radiation therapy in the 1950s, the treatment of Hodgkin lymphoma has continued to evolve, balancing cure and toxicity. This approach has resulted in low rates of relapse and death and fewer short and late toxicities from the treatments used in pursuit of cure. To achieve this balance, the field has continued to progress into an exciting era where the advent of more targeted therapies such as brentuximab vedotin, immunotherapies such as PD-1 inhibitors, and chimeric antigen receptor T-cells (CAR-T) targeted at CD30 are changing the landscape. As in the past, cooperative group and international collaborations are key to continuing to drive the science forward. Increased focus on patient-reported outcomes can further contribute to the goal of improved outcomes by examining the impact on the individual patient in the acute phase of therapy and on long-term implications for survivors. The goals of this review are to summarize recent and current clinical trials including reduction or elimination of radiation, immunotherapies and biologically-targeted agents, and discuss the use of patient-reported outcomes to help discern directions for new therapeutic regimens and more individualized evaluation of the balance of cure and toxicity.

Molecular biology of Hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is unique among lymphoid malignancies in several key biological features. (i) The Hodgkin and Reed-Sternberg (HRS) tumor cells are rare among an extensive and complex microenvironment. (ii) They derive from B cells, but have largely lost the B-cell typical gene expression program. (iii) Their specific origin appears to be pre-apoptotic germinal center (GC) B cells. (iv) They consistently develop bi- or multinucleated Reed-Sternberg cells from mononuclear Hodgkin cells. (v) They show constitutive activation of numerous signaling pathways. Recent studies have begun to uncover the basis of these specific features of cHL: HRS cells actively orchestrate their complex microenvironment and attract many distinct subsets of immune cells into the affected tissues, to support their survival and proliferation, and to create an immunosuppressive environment. Reed-Sternberg cells are generated by incomplete cytokinesis and refusion of Hodgkin cells. Epstein-Barr virus (EBV) plays a major role in the rescue of crippled GC B cells from apoptosis and hence is a main player in early steps of lymphomagenesis of EBV⁺ cHL cases. The analysis of the landscape of genetic lesions in HRS cells so far did not reveal any highly recurrent HRS cell-specific lesions, but major roles of genetic lesions in members of the NF-κB and JAK/STAT pathways and of factors of immune evasion. It is perhaps the combination of the genetic lesions and the peculiar cellular origin of HRS cells that are disease defining. A combination of such genetic lesions and multiple cellular interactions with cells in the microenvironment causes the constitutive activation of many signaling pathways, often interacting in complex fashions. In nodular lymphocyte predominant Hodgkin lymphoma, the GC B cell-derived tumor cells have largely retained their typical GC B-cell expression program and follicular microenvironment. For IgD-positive cases, bacterial antigen triggering has recently been implicated in early stages of its pathogenesis.

Scutellariabarbata D. Don extraction selectively targets stemness-prone NSCLC cells by attenuating SOX2/SMO/GLI1 network loop

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellariabarbata D. Don extraction (SBE), a traditional Chinese medicine, has been proved effective against various malignant disorders in clinics with tolerable side-effects when administered alone or in combination with conventional chemotherapeutic regimens.

AIM OF THIS STUDY

Multi-drug resistance of cancer is attributed to existence of cancer stemness-prone cells that harbor aberrantly high activation of Sonic Hedgehog (SHH) cascade. Our previous study has demonstrated that SBE sensitized non-small cell lung cancer (NSCLC) cells to Cisplatin (DDP) treatment by downregulating SHH pathway. Yet, whether SBE could prohibit proliferation of cancer stemness-prone cells and its underlying molecular mechanisms remain to be investigated. In this article, we further investigated intervention of SBE on NSCLC cell stemness-associated phenotypes and its potential mode of action.

MATERIALS AND METHODS

CCK-8 and clonal formation detection were used to measure the anti-proliferative potency of SBE against NSCLC and normal epithelial cells. Sphere formation assay and RQ-PCR were used to detect proliferation of cancer stemness cells and associated marker expression upon SBE incubation. Mechanistically, DARTS-WB and SPR were used to unveil binding target of SBE. Immunodeficient mice were implanted with patient derived tumor bulk for in vivo validation of anti-cancer effect of SBE.

RESULTS

SBE selectively attenuated proliferation and stemness-like phenotypes of NSCLC cells rather than bronchial normal epithelial cells. Drug-protein interaction analysis revealed that SBE could directly bind with stem cell-specific transcription factor sex determining region Y-box 2 (SOX2) and interfere with the SOX2/SMO/GLI1 positive loop. In vivo assay using patient-derived xenografts (PDXs) model further proved that SBE diminished tumor growth and SOX2 expression in vivo.

CONCLUSION

Our data indicate that SBE represses stemness-related features of NSCLC cells via targeting SOX2 and may serve as an alternative therapeutic option for clinic treatment.

Sodium selenite attenuates lung adenocarcinoma progression by repressing SOX2-mediated stemness

PURPOSE

Sodium selenite (SS) has been widely reported to induce apoptosis in various cancer cell types. However, the underlying molecular mechanisms governing SS-mediated repression of lung cancer stem cells remain largely undefined.

METHODS

In vitro assays of cell proliferation, clonal formation, apoptosis, migration and cancer stemness cell sphere formation were performed to examine the inhibitory effects of SS on lung adenocarcinoma (LAD) cells with or without the overexpression of SRY-related high-mobility-group box 2 (SOX2).

RESULTS

SS significantly inhibited cell growth and induced apoptosis in LAD cells in a dose-dependent manner with marginal effects on normal epithelial cell HBEC. SS dramatically repressed expression of SOX2 and its upstream regulator GLI1 and strongly decreased stemness sphere formation in LAD cells at 10 µM. Forced expression of SOX2 significantly buffered anti-cancer effects of SS.

CONCLUSIONS

Our results demonstrate that SS attenuates lung adenocarcinoma progression by repressing SOX2 and its upstream regulator GLI1, which suggests that SS may be a potential therapeutic drug candidate for lung cancer patients.

Biology of classical Hodgkin lymphoma: implications for prognosis and novel therapies

Hodgkin lymphoma is considered a prime example of treatment success, with cure rates exceeding 80% using modern combined modality therapies. However, especially in adolescents and young adults, treatment-related toxicity and long-term morbidity still represent persistent challenges. Moreover, outcomes in patients with relapsed or refractory disease remain unfavorable in the era of high-dose chemotherapy and stem-cell transplantation. Hence, there is a high demand for novel and innovative alternative treatment approaches. In recent years, many new therapeutic agents have emerged from preclinical and clinical studies that target molecular hallmarks of Hodgkin lymphoma, including the aberrant phenotype of the tumor cells, deregulated oncogenic pathways, and immune escape. The antibody-drug conjugate brentuximab vedotin and immune checkpoint inhibitors have already shown great success in patients with relapsed/refractory disease, leading to US Food and Drug Administration approval and new trials testing these agents in various clinical settings. The expanding knowledge and understanding of Hodgkin lymphoma biology and disease progression, as well as the development of robust tools for biomarker-driven risk stratification and therapeutic decision making, continue to be fundamentally important for the success of these and other novel agents. We anticipate that the availability and clinical implementation of novel molecular assays will be instrumental in an era of rapid shifts in the treatment landscape of this disease. Here, we review the current knowledge of Hodgkin lymphoma pathobiology, highlighting the related development of novel treatment strategies and prognostic models that hold the promise to continually challenge and change the current standard of care in classical Hodgkin lymphoma.