Sonic Hedgehog Signaling in Organogenesis, Tumors, and Tumor Microenvironments

Therapeutic implication of Sonic Hedgehog as a potential modulator in ischemic injury

Sonic Hedgehog (SHh) is a homology protein that is involved in the modeling and development of embryonic tissues. As SHh plays both protective and harmful roles in ischemia, any disruption in the transduction and regulation of the SHh signaling pathway causes ischemia to worsen. The SHh signal activation occurs when SHh binds to the receptor complex of Ptc-mediated Smoothened (Smo) (Ptc-smo), which initiates the downstream signaling cascade. This article will shed light on how pharmacological modifications to the SHh signaling pathway transduction mechanism alter ischemic conditions via canonical and non-canonical pathways by activating certain downstream signaling cascades with respect to protein kinase pathways, angiogenic cytokines, inflammatory mediators, oxidative parameters, and apoptotic pathways. The canonical pathway includes direct activation of interleukins (ILs), angiogenic cytokines like hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and hypoxia-inducible factor alpha (HIF-), which modulate ischemia. The non-canonical pathway includes indirect activation of certain pathways like mTOR, PI3K/Akt, MAPK, RhoA/ROCK, Wnt/-catenin, NOTCH, Forkhead box protein (FOXF), Toll-like receptors (TLR), oxidative parameters such as GSH, SOD, and CAT, and some apoptotic parameters such as Bcl2. This review provides comprehensive insights that contribute to our knowledge of how SHh impacts the progression and outcomes of ischemic injuries.

The biology of SCUBE

The SCUBE [Signal peptide-Complement C1r/C1s, Uegf, Bmp1 (CUB)-Epithelial growth factor domain-containing protein] family consists of three proteins in vertebrates, SCUBE1, 2 and 3, which are highly conserved in zebrafish, mice and humans. Each SCUBE gene encodes a polypeptide of approximately 1000 amino acids that is organized into five modular domains: (1) an N-terminal signal peptide sequence, (2) nine tandem epidermal growth factor (EGF)-like repeats, (3) a large spacer region, (4) three cysteine-rich (CR) motifs, and (5) a CUB domain at the C-terminus. Murine Scube genes are expressed individually or in combination during the development of various tissues, including those in the central nervous system and the axial skeleton. The cDNAs of human SCUBE orthologs were originally cloned from vascular endothelial cells, but SCUBE expression has also been found in platelets, mammary ductal epithelium and osteoblasts. Both soluble and membrane-associated SCUBEs have been shown to play important roles in physiology and pathology. For instance, upregulation of SCUBEs has been reported in acute myeloid leukemia, breast cancer and lung cancer. In addition, soluble SCUBE1 is released from activated platelets and can be used as a clinical biomarker for acute coronary syndrome and ischemic stroke. Soluble SCUBE2 enhances distal signaling by facilitating the secretion of dual-lipidated hedgehog from nearby ligand-producing cells in a paracrine manner. Interestingly, the spacer regions and CR motifs can increase or enable SCUBE binding to cell surfaces via electrostatic or glycan-lectin interactions. As such, membrane-associated SCUBEs can function as coreceptors that enhance the signaling activity of various serine/threonine kinase or tyrosine kinase receptors. For example, membrane-associated SCUBE3 functions as a coreceptor that promotes signaling in bone morphogenesis. In humans, SCUBE3 mutations are linked to abnormalities in growth and differentiation of both bones and teeth. In addition to studies on human SCUBE function, experimental results from genetically modified mouse models have yielded important insights in the field of systems biology. In this review, we highlight novel molecular discoveries and critical directions for future research on SCUBE proteins in the context of cancer, skeletal disease and cardiovascular disease.

MALAT1 functions as a transcriptional promoter of MALAT1::GLI1 fusion for truncated GLI1 protein expression in cancer

BACKGROUND

The long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a cancer biomarker. Furthermore, fusion of the MALAT1 gene with glioma-associated oncogene 1 (GLI1) is a diagnostic marker of plexiform fibromyxoma and gastroblastoma; however, the function of this fusion gene remains unexplored.

METHOD

In this study, we elucidate the structure and function of the MALAT1::GLI1 fusion gene. To this end, we determined a transcriptional start site (TSS) and promoter region for truncated GLI1 expression using rapid amplification of the 5' cDNA end and a luciferase reporter assay in cultured cells transfected with a plasmid harboring the MALAT1::GLI1 fusion gene.

RESULTS

We found that the TATA box, ETS1 motif, and TSS were located in MALAT1 and that MALAT1 exhibited transcriptional activity and induced expression of GLI1 from the MALAT1::GLI1 fusion gene. Truncated GLI1, lacking SUMOylation and SUFU binding sites and located in the nucleus, upregulated mRNA expression of GLI1 target genes in the hedgehog signaling pathway.

CONCLUSIONS

We demonstrate a distinct and alternative function of MALAT1 as a transcriptional promoter for expression of the MALAT1::GLI1 fusion gene. Our findings will aid future research on MALAT1 and its fusion gene partners.

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.

The Role of Hypoxia and Cancer Stem Cells in Development of Glioblastoma

Glioblastoma multiform (GBM) is recognized as the most malignant brain tumor with a high level of hypoxia, containing a small population of glioblastoma stem like cells (GSCs). These GSCs have the capacity of self-renewal, proliferation, invasion and recapitulating the parent tumor, and are major causes of radio-and chemoresistance of GBM. Upregulated expression of hypoxia inducible factors (HIFs) in hypoxia fundamentally contributes to maintenance and progression of GSCs. Therefore, we thoroughly reviewed the currently acknowledged roles of hypoxia-associated GSCs in development of GBM. In detail, we recapitulated general features of GBM, especially GSC-related features, and delineated essential responses resulted from interactions between GSC and hypoxia, including hypoxia-induced signatures, genes and pathways, and hypoxia-regulated metabolic alterations. Five hypothesized GSC niches are discussed and integrated into one comprehensive concept: hypoxic peri-arteriolar niche of GSCs. Autophagy, another protective mechanism against chemotherapy, is also closely related to hypoxia and is a potential therapeutic target for GBM. In addition, potential causes of therapeutic resistance (chemo-, radio-, surgical-, immuno-), and chemotherapeutic agents which can improve the therapeutic effects of chemo-, radio-, or immunotherapy are introduced and discussed. At last, as a potential approach to reverse the hypoxic microenvironment in GBM, hyperbaric oxygen therapy (HBOT) might be an adjuvant therapy to chemo-and radiotherapy after surgery. In conclusion, we focus on demonstrating the important role of hypoxia on development of GBM, especially by affecting the function of GSCs. Important advantages have been made to understand the complicated responses induced by hypoxia in GBM. Further exploration of targeting hypoxia and GSCs can help to develop novel therapeutic strategies to improve the survival of GBM patients.

Novel sonic hedgehog gene variant in a patient with hyponatremia, microsomia, and midline defects; phenotype description in association with a variant of unknown significance [c.755_757del p.(Phe252del)] and an approach to salt-wasting in SHH-related adrenal disorders

OBJECTIVE

To contribute a novel sonic hedgehog (SHH) gene variant in association with a novel-meagerly described phenotype and discuss SHH signaling pathway pathology.

CASE PRESENTATION

We present a 5-year-old boy with excessive hyponatremia and natriuresis, microform holoprosencephaly and microsomia, with morphologically intact hypothalamic-pituitary-adrenal (HPA) axis, and hypoaldosteronism, yet without hyperreninemia, hyperkalemia, dehydration episodes, or glucocorticoid insufficiency. Extensive workup excluded common causes of salt-wasting and revealed a novel variant of unknown significance on the sonic hedgehog (SHH) gene; NM_000193.4:c.755_757del (p.Phe252del), in heterozygosity.

CONCLUSIONS

Salt-wasting in children is predominantly caused by central nervous system lesions, renal tubular dysfunction, or adrenal insufficiency. The SHH protein is a signaling molecule, essential in embryogenesis-including HPA axis differentiation. Inactivating SHH variants disrupt the signaling pathway, leading to dysplasia or dysfunction of target organs. What's new: • We analyze the patient's phenotype in the light of this novel variant • Patient's isolated aldosterone deficiency possibly implies a selective signaling defect affecting the development of adrenal zona glomerulosa • Unexplained hyporeninemia and hypokalemia in the context of hypoaldosteronism raise questions on SHH signaling pathophysiology.

STIL/AURKA axis promotes cell proliferation by influencing primary cilia formation in bladder cancer

BACKGROUND

The primary cilia (PC) is a microtubule-based and nonmotile organelle which protrudes from the surface of almost all mammalian cells. At present, PC has been found to be a deficiency or loss in multiple cancers. Restoring PC could be a novel targeting therapy strategy. Our research showed that PC was reduced in human bladder cancer (BLCA) cells, and PC deficiency promotes cell proliferation. However, the concrete mechanisms remain unknown. SCL/TAL1 interrupting locus (STIL), a PC-related protein, was screened in our previous study and could influence the cell cycle by regulating PC in tumor cells. In this study, we aimed to elucidate the function of STIL for PC to explore the underlying mechanism of PC in BLCA.

METHODS

Public database analysis, western blot, and enzyme-linked immunosorbent assay (ELISA) were used to screen genes and explore gene expression alteration. Immunofluorescence and western blot were utilized to investigate PC. Wound healing assay, clone formation assay, and CCK-8 assay were used to explore cell migration, growth, and proliferation. The co-immunoprecipitation and western blot were employed to reveal the interaction of STIL and AURKA.

RESULTS

We found that high STIL expression is correlated with poor outcomes of BLCA patients. Further analysis revealed that STIL overexpression could inhibit PC formation, activate SHH signaling pathways, and promote cell proliferation. In contrast, STIL-knockdown could promote PC formation, inactivate SHH signaling, and inhibit cell proliferation. Furthermore, we found that the regulatory functions of STIL for PC depend on AURKA. STIL could influence proteasome activity and maintain AURKA stabilization. AURKA-knockdown could reverse PC deficiency caused by STIL overexpression for PC in BLCA cells. We observed that co-knockdown in STIL and AURKA significantly enhanced PC assembly.

CONCLUSION

In summary, our result provides a potential therapy target for BLCA based on the restoration of PC.

The Role of Genetic Mutations in Mitochondrial-Driven Cancer Growth in Selected Tumors: Breast and Gynecological Malignancies

There is an increasing understanding of the molecular and cytogenetic background of various tumors that helps us better conceptualize the pathogenesis of specific diseases. Additionally, in many cases, these molecular and cytogenetic alterations have diagnostic, prognostic, and/or therapeutic applications that are heavily used in clinical practice. Given that there is always room for improvement in cancer treatments and in cancer patient management, it is important to discover new therapeutic targets for affected individuals. In this review, we discuss mitochondrial changes in breast and gynecological (endometrial and ovarian) cancers. In addition, we review how the frequently altered genes in these diseases (BRCA1/2, HER2, PTEN, PIK3CA, CTNNB1, RAS, CTNNB1, FGFR, TP53, ARID1A, and TERT) affect the mitochondria, highlighting the possible associated individual therapeutic targets. With this approach, drugs targeting mitochondrial glucose or fatty acid metabolism, reactive oxygen species production, mitochondrial biogenesis, mtDNA transcription, mitophagy, or cell death pathways could provide further tailored treatment.

The Hedgehog/GLI signaling pathway activates transcription of Slug (Snail2) in melanoma cells

In melanoma and other cancers, invasion, epithelial-to-mesenchymal transition, metastasis and cancer stem cell maintenance are regulated by transcription factors including the Snail family. Slug (Snail2) protein generally supports migration and apoptosis resistance. However, its role in melanoma is not completely understood. The present study investigated the transcriptional regulation of the SLUG gene in melanoma. It demonstrated that SLUG is under the control of the Hedgehog/GLI signaling pathway and is activated predominantly by the transcription factor GLI2. The SLUG gene promoter contains a high number of GLI-binding sites. Slug expression is activated by GLI factors in reporter assays and inhibited by GANT61 (GLI inhibitor) and cyclopamine (SMO inhibitor). SLUG mRNA levels are lowered by GANT61 as assessed by reverse transcription-quantitative PCR. Chromatin immunoprecipitation revealed abundant binding of factors GLI1-3 in the four subregions of the proximal SLUG promoter. Notably, melanoma-associated transcription factor (MITF) is an imperfect activator of the SLUG promoter in reporter assays, and downregulation of MITF had no effect on endogenous Slug protein levels. Immunohistochemical analysis confirmed the above findings and showed MITF-negative regions in metastatic melanoma that were positive for GLI2 and Slug. Taken together, the results demonstrated a previously unrecognized transcriptional activation mechanism of the SLUG gene, which may represent its main regulation of expression in melanoma cells.

Antitumor activity and mechanism of cucurbitacin B in A549/DDP cells

Cucurbitacin B (CuB) is a class of tetracyclic triterpenoids isolated from Cucurbitaceae with a wide range of anti-inflammatory and anti-tumor activities, mainly used in hepatitis and hepatocellular carcinoma, while there is relatively little research and application of this drug for lung cancer. In this study, CuB was administered on A549/DDP cells to observe how it affected the cells and their mechanism of action. CuB demonstrated good anti-tumor activity against A549/DDP cells in a dose-dependent manner and caused changes in the hedgehog (Hh) pathway. The results showed that CuB greatly inhibits the proliferation and the invasion of A549/DDP cells, and promoted apoptosis of A549/DDP cells. Meanwhile, it changed the expression of p53-related genes at the RNA and protein level. In conclusion, this experiment provides a theoretical basis for new applications of CuB and new thoughts on the mechanism of its anti-tumor activity, and provides a direction for deep research.

Impact of neuroinflammation on epigenetic transcriptional control of Sonic Hedgehog members in the central nervous system

Sonic Hedgehog (Shh) signaling plays a critical role during central nervous system (CNS) development, and its dysregulation leads to neurological disorders. Nevertheless, little is known about Shh signaling regulation in the adult brain. Here, we investigated the contribution of DNA methylation on the transcriptional control of Shh signaling pathway members and its basal distribution impact on the brain, as well as its modulation by inflammation. The methylation status of the promoter regions of these members and the transcriptional profile of DNA-modifying enzymes (DNA Methyltransferases - DNMTs and Tet Methylcytosine Dioxygenase - TETs) were investigated in a murine model of neuroinflammation by qPCR. We showed that, in the adult brain, methylation in the CpG promoter regions of the Shh signaling pathway members was critical to determine the endogenous differential transcriptional pattern observed between distinct brain regions. We also found that neuroinflammation differentially modulates gene expression of DNA-modifying enzymes. This study reveals the basal transcriptional profile of DNMTs and TETs enzymes in the CNS and demonstrates the effect of neuroinflammation on the transcriptional control of members of the Shh Signaling pathway in the adult brain.

Cellular and Molecular Biology of Cancer Stem Cells of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death globally. The cancer stem cells (CSCs) of HCC are responsible for tumor growth, invasion, metastasis, recurrence, chemoresistance, target therapy resistance and radioresistance. The reported main surface markers used to identify liver CSCs include epithelial cell adhesion/activating molecule (EpCAM), cluster differentiation 90 (CD90), CD44 and CD133. The main molecular signaling pathways include the Wnt/β-catenin, transforming growth factors-β (TGF-β), sonic hedgehog (SHH), PI3K/Akt/mTOR and Notch. Patients with EpCAM-positive alpha-fetoprotein (AFP)-positive HCC are usually young but have advanced tumor-node-metastasis (TNM) stages. CD90-positive HCCs are usually poorly differentiated with worse prognosis. Those with CD44-positive HCC cells develop early metastases. Those with CD133 expression have a higher recurrence rate and a shorter overall survival. The Wnt/β-catenin signaling pathway triggers angiogenesis, tumor infiltration and metastasis through the enhancement of angiogenic factors. All CD133+ liver CSCs, CD133+/EpCAM+ liver CSCs and CD44+ liver CSCs contribute to sorafenib resistance. SHH signaling could protect HCC cells against ionizing radiation in an autocrine manner. Reducing the CSC population of HCC is crucial for the improvement of the therapy of advanced HCC. However, targeting CSCs of HCC is still challenging.

Traditional Chinese Medicine has great potential as candidate drugs for lung cancer: A review

ETHNOPHARMACOLOGICAL RELEVANCE

With high mortality and morbidity rates, lung cancer (LC) has become one of the major threats to human health. The treatment strategies for LC currently face issues, such as drug resistance and body tolerance. Traditional Chinese medicine (TCM) is characterized by novel pharmacological mechanisms, low toxicity, and limited side effects. TCM includes a substantial number of biologically active ingredients, several of which are effective monomeric agents against LC. An increasing number of researchers are focusing their efforts on the discovery of active anti-cancer ingredients in TCM.

AIM OF THE REVIEW

In this review, we summarized the anti-LC mechanisms of five types of TCM monomeric compounds. Our goal is to provide research ideas for the identification of new prospective medication candidates for the treatment of LC.

MATERIALS AND METHODS

We collected reports on the anti-LC effects of TCM monomers from web databases, including PubMed, Science Direct, Web of Science, and Europe PubMed Central. Among the keywords used were "lung cancer," "traditional Chinese medicine," "pharmacology," and their combinations thereof. Then, we systematically summarized the anti-LC efficacy and related mechanisms of TCM monomers.

RESULTS

Based on the available literature, this paper reviewed the therapeutic effects and mechanisms of five types of TCM monomers on LC. The characteristics of TCM monomers include the capabilities to suppress the tumor cell cycle, inhibit proliferation, induce apoptosis, promote autophagy, inhibit tumor cell invasion and metastasis, and enhance efficacy or reduce drug resistance when combined with cytotoxic agents and other methods to arrest the progression of LC and prolong the survival of patients.

CONCLUSIONS

TCM contains numerous flavonoids, alkaloids, terpenoids, polyphenols, and other active compounds that are effective against LC. Given their chemical structure and pharmacological properties, these monomers are suitable as candidate drugs for the treatment of LC.

Targeting cancer stem cell pathways for lung cancer therapy

PURPOSE OF REVIEW

The unique properties of cancer stem cells (CSCs) make lung cancer untargetable for quite an extended period. The functional mechanism of this cell type has been illustrated step by step. However, the outcomes of lung cancer patients are still lower than expected clinically. The attempts made by scientists to make challenge history against stemness maintenance of lung cancer cells and their druggable targets are worth elucidating.

RECENT FINDINGS

Many agents, including the Bispecific T-cell engager (BiTE) and AMG 119 targeting DLL3-positive cells, are a tremendous breakthrough in the preclinical and clinical treatment of SCLC. More studies focus on targeting CSCs to overcome TKI resistance in NSCLC. The combo targeting of CSC and the immune microenvironment can favor the treatment of lung cancer patients.

SUMMARY

The current review elucidates the characteristics and related regulating pathways of lung CSCs from essential to preclinical research. We retrospectively introduce an update on the clinical development of therapeutics targeting CSC-associated developmental signaling pathways and discuss the opportunities to target CSC-immune interactions in lung cancer.

SHH/GLI2-TGF-β1 feedback loop between cancer cells and tumor-associated macrophages maintains epithelial-mesenchymal transition and endoplasmic reticulum homeostasis in cholangiocarcinoma

BACKGROUND

Tumor-associated macrophages (TAMs) play a dual role in tumors. However, the factors which drive the function of TAMs in cholangiocarcinoma remain largely undefined.

METHODS

SHH signaling pathway and endoplasmic reticulum stress (ERS) indicators were detected in clinical tissues and cholangiocarcinoma cell lines. TAMs were co-cultured with cholangiocarcinoma cells under conditions of hypoxia/normoxia. Polarized TAMs were counted by flow cytometry, and TGF-β1 levels in cell supernatants were detected by ELISA. The effects of glioma-associated oncogene GLI2 on TAMs themselves and cholangiocarcinoma cells were examined by conducting interference and overexpression assays.

RESULTS

The SHH signaling pathway and ERS were both activated in tumor tissues or tumor cell lines under conditions of hypoxia. In co-culture experiments, the presence of cholangiocarcinoma cells increased the proportion of M2-polarized TAMs and the secretion of TGF-β1 by TAMs, while knockdown of SHH expression reversed those increases. Overexpression of GLI2 in TAMS or stimulation of TAMS with Hh-Ag1.5 increased their levels of TGF-β1 expression. Furthermore, under co-culture conditions, interference with GLI2 expression in TAMs reduced the tumor cell migration, invasion, and ER homeostasis induced by Hh-Ag1.5-pretreated TAMs. Under conditions of hypoxia, the presence of cholangiocarcinoma cells promoted the expression of GLI2 and TGF-β1 in Tams, and in turn, TAMs inhibited the apoptosis and promoted the migration and invasion of cholangiocarcinoma cells. In vivo, an injection of cholangiocarcinoma cells plus TAMs contributed to the growth, EMT, and ER homeostasis of tumor tissue, while an injection of TAMs with GLI2 knockdown had the opposite effects.

CONCLUSION

Cholangiocarcinoma cells regulated TAM polarization and TGF-β1 secretion via a paracrine SHH signaling pathway, and in turn, TAMs promoted the growth, EMT, and ER homeostasis of cholangiocarcinoma cells via TGF-β1.

The emerging roles of Hedgehog signaling in tumor immune microenvironment

The Hedgehog (Hh) signaling pathway is pervasively involved in human malignancies, making it an effective target for cancer treatment for decades. In addition to its direct role in regulating cancer cell attributes, recent work indicates that it has an immunoregulatory effect on tumor microenvironments. An integrated understanding of these actions of Hh signaling pathway in tumor cells and tumor microenvironments will pave the way for novel tumor treatments and further advances in anti-tumor immunotherapy. In this review, we discuss the most recent research about Hh signaling pathway transduction, with a particular emphasis on its role in modulating tumor immune/stroma cell phenotype and function, such as macrophage polarity, T cell response, and fibroblast activation, as well as their mutual interactions between tumor cells and nonneoplastic cells. We also summarize the recent advances in the development of Hh pathway inhibitors and nanoparticle formulation for Hh pathway modulation. We suggest that targeting Hh signaling effects on both tumor cells and tumor immune microenvironments could be more synergistic for cancer treatment.

Non-Apoptotic Programmed Cell Death in Thyroid Diseases

Thyroid disorders are among the most common endocrinological conditions. As the prevalence of thyroid diseases increases annually, the exploration of thyroid disease mechanisms and the development of treatments are also gradually improving. With the gradual advancement of therapies, non-apoptotic programmed cell death (NAPCD) has immense potential in inflammatory and neoplastic diseases. Autophagy, pyroptosis, ferroptosis, and immunogenic cell death are all classical NAPCD. In this paper, we have compiled the recent mechanistic investigations of thyroid diseases and established the considerable progress by NAPCD in thyroid diseases. Furthermore, we have elucidated the role of various types of NAPCD in different thyroid disorders. This will help us to better understand the pathophysiology of thyroid-related disorders and identify new targets and mechanisms of drug resistance, which may facilitate the development of novel diagnostic and therapeutic strategies for patients with thyroid diseases. Here, we have reviewed the advances in the role of NAPCD in the occurrence, progression, and prognosis of thyroid diseases, and highlighted future research prospects in this area.

WNT5A, β‑catenin and SUFU expression patterns, and the significance of microRNA deregulation in placentas with intrauterine growth restriction

Placental insufficiency is a common cause of intrauterine growth restriction (IUGR). It affects ~10% of pregnancies and increases fetal and neonatal morbidity and mortality. Although Wnt and Hh pathways are crucial for embryonic development and placentation, their role in the pathology of IUGR is still not sufficiently explored. The present study analyzed the expression of positive regulators of the Wnt pathway, WNT5A and β‑catenin, and the expression of the Hh pathway negative regulator suppressor of fused (SUFU). Immunohistochemical and reverse transcription‑quantitative PCR (RT‑qPCR) assays were performed on 34 IUGR and 18 placental tissue samples from physiologic singleton‑term pregnancies. Epigenetic mechanisms of SUFU gene regulation were also investigated by methylation‑specific PCR analysis of its promoter and RT‑qPCR analysis of miR‑214‑3p and miR‑378a‑5p expression. WNT5A protein expression was higher in endothelial cells of placental villi from IUGR compared with control tissues. That was also the case for β‑catenin protein expression in trophoblasts and endothelial cells and SUFU protein expression in trophoblasts from IUGR placentas. The SUFU gene promoter remained unmethylated in all tissue samples, while miR‑214‑3p and miR‑378a‑5p were downregulated in IUGR. The present results suggested altered Wnt and Hh signaling in IUGR. DNA methylation did not appear to be a mechanism of SUFU regulation in the pathogenesis of IUGR, but its expression could be regulated by miRNA targeting.

Malignancies in Patients with Interstitial Lung Diseases: A Single Center Observational Study

OBJECTIVE

Current studies focus on the prevalence rate of lung cancer in idiopathic pulmonary fibrosis and connective tissue disease-associated interstitial lung disease (CTD-LID). Our aim was to investigate the prevalence of malignancies in patients with various subtypes of ILD.

METHODS

A total of 5350 patients diagnosed with ILD between January 2015 and December 2021 were retrospectively included. The prevalence of different malignancies and different ILDs was assessed using complete follow-up data.

RESULTS

A total of 248 patients (139 males; 65-IQR, 57 to 72-years) out of 5350 patients with ILD were confirmed with malignancies. A total of 69% of patients with ILD and malignances were older than 60 years old. The prevalence of malignancies in ILD patients was 4.6%, and lung cancer had the most common incidence of 1.9%, followed by malignancies in the digestive system of 0.9%. Among the different ILD subtypes, the prevalence of malignancies such as organizing pneumonia (OP), idiopathic pulmonary fibrosis (IPF), anti-neutrophil cytoplasmic antibodies-associated vasculitis-related ILD(AAV-ILD), nonspecific interstitial pneumonia (NSIP), CTD-ILD, hypersensitivity pneumonitis (HP), sarcoidosis, and other types of ILD was 6.8%, 5.0%, 4.7%, 4.3%, 2.5%, 2.2%, 1.2%, and 6.9%, respectively. The incidence of lung cancer as the most common tumor in IPF was 3.9%, with adenocarcinoma predominating (1.7%). The highest rate of malignancy occurring in RA of CTD-ILD was 2.4%.

CONCLUSION

Older patients with ILD (≥60 years) including OP, IPF, AAV-ILD, NSIP, CTD-ILD, and HP, were associated with a higher incidence of malignancy, especially males aged from 60 to 69 years. These epidemiological results indicate that it is essential for physicians to pay more attention to the screening of and management strategies for different malignancies, according to the specific ILD subtypes.

Long Non-Coding RNA Expression Profile Alteration Induced by Titanium Dioxide Nanoparticles in HepG2 Cells

The liver is considered the major target organ affected by oral exposure to titanium dioxide nanoparticles (TiO₂ NPs), but the mechanism of hepatotoxicity is not fully understood. This study investigated the effect of TiO₂ NPs on the expression profile of long non-coding RNA (lncRNA) in hepatocytes and tried to understand the potential mechanism of hepatotoxicity through bioinformatics analysis. The human hepatocellular carcinoma cells (HepG2) were treated with TiO₂ NPs at doses of 0-200 μg/mL for 48 h and then RNA sequencing was implemented. The differential lncRNAs between the control and TiO₂ NPs-treated groups were screened, then the lncRNA-mRNA network and enrichment pathways were analyzed via multivariate statistics. As a result, 46,759 lncRNAs were identified and 129 differential lncRNAs were screened out. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the targeted mRNAs of those differential lncRNAs were enriched in the Hedgehog signaling pathway, Vasopressin-regulated water reabsorption, and Glutamatergic synapse. Moreover, two lncRNA-mRNA networks, including lncRNA NONHSAT256380.1-JRK and lncRNA NONHSAT173563.1-SMIM22, were verified by mRNA detection. This study demonstrated that an alteration in the lncRNA expression profile could be induced by TiO₂ NPs and epigenetics may play an important role in the mechanism of hepatotoxicity.

Olfactory mucosa tissue-derived mesenchymal stem cells lysate ameliorates LPS-induced acute liver injury in mice

Background

Acute liver injury (ALI) induced by sepsis seriously endangers the health of human beings every year. Mesenchymal stem cells (MSCs) lysate containing various regulators had a positive effect on anti-inflammation, hoping to provide a promising strategy in ALI.

Methods

Olfactory mucosa-derived mesenchymal stem cells (OM-MSCs) were extracted and identified. The collected OM-MSCs were prepared after repeated freeze–thaw in phosphate buffer solution (PBS). Then, OM-MSCs lysate was filtered for future experiments. To understand the composes of OM-MSCs clearly, we detected the components of OM-MSCs lysate by western blotting. In vitro, OM-MSCs lysate was applied to evaluate the effects on normal human liver cells (LO-2) under stimulation of LPS. Lipopolysaccharide (LPS) was also injected intraperitoneally to build ALI model in mice. We further assessed the anti-inflammatory capacity of OM-MSCs lysate on ALI in vivo by aminotransferase determination, pathology observation, and immunohistochemical staining. Moreover, the immunoblot technique was performed to recognize the changes in inflammatory factors and related proteins.

Results

In this study, we found that OM-MSCs lysate could protect structure effectively, improve the plasma aminotransferases, diminish inflammation by releasing interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β). A significant decrease in tumor necrosis factor-α (TNF-α) also occurred under the treatment of OM-MSCs lysate. In addition, trophic factors originating from OM-MSCs lysate provided a supportive micro-environment for liver recovery. Especially, up-expression of vascular endothelial growth factor (VEGF) in vivo revealed that OM-MSCs might have a great potential for healing.

Conclusions

Our results demonstrated that OM-MSCs lysate could alleviate LPS-induced ALI via decreasing inflammatory cytokines and promoting recovery.

Analysis of Primary Cilium Expression and Hedgehog Pathway Activation in Mesothelioma Throws Back Its Complex Biology

The primary cilium (PC) is a sensory organelle present on the cell surface, modulating the activity of many pathways. Dysfunctions in the PC lead to different pathologic conditions including cancer. Hedgehog signaling (Hh) is regulated by PC and the loss of its control has been observed in many cancers, including mesothelioma. Malignant pleural mesothelioma (MPM) is a fatal cancer of the pleural membranes with poor therapeutic options. Recently, overexpression of the Hh transcriptional activator GL1 has been demonstrated to be associated with poor overall survival (OS) in MPM. However, unlike other cancers, the response to G-protein-coupled receptor smoothened (SMO)/Hh inhibitors is poor, mainly attributable to the lack of markers for patient stratification. For all these reasons, and in particular for the role of PC in the regulation of Hh, we investigated for the first time the status of PC in MPM tissues, demonstrating intra- and inter-heterogeneity in its expression. We also correlated the presence of PC with the activation of the Hh pathway, providing uncovered evidence of a PC-independent regulation of the Hh signaling in MPM. Our study contributes to the understanding MPM heterogeneity, thus helping to identify patients who might benefit from Hh inhibitors.

Resveratrol Induces Apoptosis, Suppresses Migration, and Invasion of Cervical Cancer Cells by Inhibiting the Hedgehog Signaling Pathway

To investigate the effect and mechanism of resveratrol on the biological behavior of cervical cancer cells (HeLa cells), the apoptosis, migration, and invasion of HeLa cells were detected by flow cytometry, wound healing, and transwell assays. The expression levels of Hedgehog signal pathway proteins (smoothened (SMO), zinc finger transcription factors (Gli1), and sonic hedgehog homolog (Shh)) were detected by quantitative real-time PCR (qPCR) and western blotting. Compared with that control group, resveratrol (RES) significantly induced apoptosis, inhibited the migration and invasion of the HeLa cells. The expression of SMO, Gli1, and Shh were downregulated in the HeLa cells treated with RES. The Hedgehog agonist purmorphamine (PUR) reversed the RES-induced increase of apoptosis and reduction of migration and invasion in the HeLa cells. In conclusion, RES induced the apoptosis and suppressed the migration and invasion of HeLa cells by inhibiting Hedgehog signal pathway.

Bidirectional anisotropic palladium nanozymes reprogram macrophages to enhance collaborative chemodynamic therapy of colorectal cancer

In the complex tumor microenvironment (TME), tumor-associated macrophages (TAMs) play an important role in immunosuppression and tumor growth; hence, tumor cells are no longer the only target during tumor treatment. However, how to simultaneously target both tumor cells and TAMs to effectively eliminate the tumor remains a challenge. Herein, based on the specific receptors for cancer cells and TAMs, we prepared bidirectional anisotropic palladium nanoclusters (Pd-HA+Pd-M@R NPs) to simultaneously target tumor cells and TAMs for enhancing the therapeutic effect. In these nanoclusters, the Pd-HA part was obtained by modifying hyaluronic acid (HA) on the surface of ultra-small Pd nanozymes that could target CT26 cells. Moreover, with the high peroxidase (POD) and catalase (CAT) activity of Pd nanozymes, Pd-HA NPs directly caused cancer cell death by producing H₂O₂ and highly toxic reactive oxygen therapy (ROS) through chemodynamic therapy (CDT). The other part of Pd NPs functioned as a carrier that linked mannose (Man) and the imiquimod molecule (R837) to obtain Pd-M@R NPs, which could specifically connect the mannose receptor of TAMs and perform targeted reprogramming of TAMs to M1 phenotype to reverse immunosuppression and further activate immunotherapy to form "double therapy". Therefore, the strategy of "double therapy" provides new sights for treating malignant tumors. STATEMENT OF SIGNIFICANCE: The bidirectional anisotropic Pd nanoclusters (Pd-HA+Pd-M@R NPs) that can simultaneously target the tumor cells and TAMs with the modification of HA and mannose, respectively. Under the biodirectional anisotropic effect, the Pd nanozymes in Pd-HA can directly kill CT 26 cells through catalyze producing toxic ROS. The Pd-M@R exhibited effectively delivery the imiquimod molecule (R837) to TAMs and specifically induced it transformed into M1 phenotype to reverse tumor immunosuppression to form the "double therapy".

Targeting hedgehog signaling in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer related death. The urgent need for effective therapies is highlighted by the lack of adequate targeting. In PDAC, hedgehog (Hh) signaling is known to be aberrantly activated, which prompted the pathway as a possible target for effective treatment for PDAC patients. Unfortunately, specific targeting of upstream molecules within the Hh signaling pathway failed to bring clinical benefit. This led to the ongoing debate on Hh targeting as a therapeutic treatment for PDAC patients. Additionally, concurrent non-canonical activation routes also result in translocation of Gli transcription factors into the nucleus. Therefore, different downstream targets of the Hh signaling pathway were identified and evaluated in preclinical and clinical research. In this review we summarize the variety of Hh signaling antagonists in different preclinical models of PDAC. Furthermore, we discuss published and ongoing clinical trials that evaluated Hh antagonists and point out the current hurdles and future perspectives in the light of redesigning Hh-targeting therapies for the treatment of PDAC patients.

Selective targeting BMP2 and 4 in SMAD4 negative esophageal adenocarcinoma inhibits tumor growth and aggressiveness in preclinical models

PURPOSE

Abnormalities within the Sonic Hedgehog (SHH), Bone Morphogenetic Protein (BMP) and SMAD4 signalling pathways have been associated with the malignant behavior of esophageal adenocarcinoma (EAC). We recently developed two specific llama-derived antibodies (VHHs), C4C4 and C8C8, which target BMP4 and BMP2/4, respectively. Here we aimed to demonstrate the feasibility of the VHHs for the treatment of EAC and to elucidate its underlying mechanism.

METHODS

Gene Set Enrichment Analysis (GSEA) was performed on a TCGA dataset, while expression of SHH, BMP2/4 and SMAD4 was validated in a cohort of EAC patients. The effects of the VHHs were tested on the recently established SMAD4(-) ISO76A primary EAC cell line and its counterpart SMAD4(+) ISO76A. In a patient-derived xenograft (PDX) model, the VHHs were evaluated for their ability to selectively target tumor cells and for their effects on tumor growth and survival.

RESULTS

High expression of BMP2/4 was detected in all SMAD4 negative EACs. SHH upregulated BMP2/4 expression and induced p38 MAPK signaling in the SMAD4(-) ISO76A cells. Inhibition of BMP2/4 by VHHs decreased the aggressive and chemo-resistant phenotype of the SMAD4(-) ISO76A but not of the SMAD4(+) ISO76A cells. In the PDX model, in vivo imaging indicated that VHHs effectively targeted tumor cells. Both VHHs significantly inhibited tumor growth and acted synergistically with cisplatin. Furthermore, we found that C8C8 significantly improved survival of the mice.

CONCLUSIONS

Our data indicate that increased BMP2/4 expression triggers aggressive non-canonical BMP signaling in SMAD4 negative EAC. Inhibiting BMP2/4 decreases malignant behavior and improves survival. Therefore, VHHs directed against BMP2/4 hold promise for the treatment of SMAD4 negative EAC.

Oncofetal proteins and cancer stem cells

Cancer stem cells (CSCs) are considered as a small population of cells with stem-like properties within the tumor bulk, and are largely responsible for tumor recurrence, metastasis, and therapy resistance. CSCs share critical features with embryonic stem cells (ESCs). The pluripotent transcription factors (TFs) and developmental signaling pathways of ESCs are invariably hijacked by CSCs termed ‘oncofetal drivers’ in many cancers, which are rarely detectable in adult tissues. The unique expression pattern makes oncofetal proteins ideal therapeutic targets in cancer treatment. Therefore, elucidation of oncofetal drivers in cancers is critical for the development of effective CSCs-directed therapy. In this review, we summarize the common pluripotent TFs such as OCT4, SOX2, NANOG, KLF4, MYC, SALL4, and FOXM1, as well as the development signaling including Wnt/β-catenin, Hedgehog (Hh), Hippo, Notch, and TGF-β pathways of ESCs and CSCs. We also describe the newly identified oncofetal proteins that drive the self-renewal, plasticity, and therapy-resistance of CSCs. Finally, we explore how the clinical implementation of targeting oncofetal drivers, including small-molecule inhibitors, vaccines, antibodies, and CAR-T (chimeric antigen receptor T cell) can facilitate the development of CSCs-directed therapy.

Study on the Mechanism of Sancao Tiaowei Decoction in the Treatment of MNNG-Induced Precancerous Lesions of Gastric Carcinoma Through Hedgehog Signaling Pathway

Sancao Tiaowei Decoction (SCTWD), a traditional Chinese medicine created by Professor Chen Weijian, has been used in the prevention and treatment of precancerous lesions of gastric carcinoma (PLGC). However, its mechanism has not been made clear. This study aimed to evaluate the therapeutic effect of SCTWD on 1-methyl-3-nitro-1-nitrosoguanidine-induced PLGC in rats and the mechanism of this effect. We found that SCTWD effectively repaired gastric mucosal injury, reversed the process of PLGC, and inhibited the occurrence of gastric cancer to some extent. In the results of hematoxylin-eosin (HE) staining, the number and arrangement of mucosal glands and the number of mononuclear cells in the lamina propria were improved in varying degrees; the enzyme-linked immunosorbent assay (ELISA) showed that the PG I and PGR of the medication treatment group were significantly higher; a Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test showed that SCTWD could significantly upregulate the expression levels of Shh, Ptch, and Gli-1 in the gastric tissue of rats. The immunohistochemical method showed that SCTWD could significantly upregulate the protein expressions of Shh, Gli-1, Smo, cyclin D1, CDKN2A/p16INK4a, and NF-κBP65 and could reduce the expression of Ptch at the same time. Through the preliminary analysis of 75 compounds screened by UPLC-Q-TOF-MS, the main components, such as organic acids, esters and anhydrides, flavonoids, phenols, tanshinones, and so on, have anti-inflammatory and anti-tumor pharmacological effects. The results of KEGG enrichment analysis showed that 5 signaling pathways related to this project were found, and 33 differential genes were presented to construct the interaction network. These results suggested that SCTWD had a good regulatory effect on PLGC and thus may have a multi-targeted effect; SCTWD can not only significantly improve the pathological changes of gastric mucosa in rats with PLGC but also exert a strong effect of the regulation of the hedgehog signaling pathway.

MDACT: A New Principle of Adjunctive Cancer Treatment Using Combinations of Multiple Repurposed Drugs, with an Example Regimen

In part one of this two-part paper, we present eight principles that we believe must be considered for more effective treatment of the currently incurable cancers. These are addressed by multidrug adjunctive cancer treatment (MDACT), which uses multiple repurposed non-oncology drugs, not primarily to kill malignant cells, but rather to reduce the malignant cells' growth drives. Previous multidrug regimens have used MDACT principles, e.g., the CUSP9v3 glioblastoma treatment. MDACT is an amalgam of (1) the principle that to be effective in stopping a chain of events leading to an undesired outcome, one must break more than one link; (2) the principle of Palmer et al. of achieving fractional cancer cell killing via multiple drugs with independent mechanisms of action; (3) the principle of shaping versus decisive operations, both being required for successful cancer treatment; (4) an idea adapted from Chow et al., of using multiple cytotoxic medicines at low doses; (5) the idea behind CUSP9v3, using many non-oncology CNS-penetrant drugs from general medical practice, repurposed to block tumor survival paths; (6) the concept from chess that every move creates weaknesses and strengths; (7) the principle of mass-by adding force to a given effort, the chances of achieving the goal increase; and (8) the principle of blocking parallel signaling pathways. Part two gives an example MDACT regimen, gMDACT, which uses six repurposed drugs-celecoxib, dapsone, disulfiram, itraconazole, pyrimethamine, and telmisartan-to interfere with growth-driving elements common to cholangiocarcinoma, colon adenocarcinoma, glioblastoma, and non-small-cell lung cancer. gMDACT is another example of-not a replacement for-previous multidrug regimens already in clinical use, such as CUSP9v3. MDACT regimens are designed as adjuvants to be used with cytotoxic drugs.

Dissection of the microRNA Network Regulating Hedgehog Signaling in Drosophila

The evolutionarily conserved Hedgehog (Hh) signaling plays a critical role in embryogenesis and adult tissue homeostasis. Aberrant Hh signaling often leads to various forms of developmental anomalies and cancer. Since altered microRNA (miRNA) expression is associated with developmental defects and tumorigenesis, it is not surprising that several miRNAs have been found to regulate Hh signaling. However, these miRNAs are mainly identified through small-scale in vivo screening or in vitro assays. As miRNAs preferentially reduce target gene expression via the 3' untranslated region, we analyzed the effect of reduced expression of core components of the Hh signaling cascade on downstream signaling activity, and generated a transgenic Drosophila toolbox of in vivo miRNA sensors for core components of Hh signaling, including hh, patched (ptc), smoothened (smo), costal 2 (cos2), fused (fu), Suppressor of fused (Su(fu)), and cubitus interruptus (ci). With these tools in hand, we performed a genome-wide in vivo miRNA overexpression screen in the developing Drosophila wing imaginal disc. Of the twelve miRNAs identified, seven were not previously reported in the in vivo Hh regulatory network. Moreover, these miRNAs may act as general regulators of Hh signaling, as their overexpression disrupts Hh signaling-mediated cyst stem cell maintenance during spermatogenesis. To identify direct targets of these newly discovered miRNAs, we used the miRNA sensor toolbox to show that miR-10 and miR-958 directly target fu and smo, respectively, while the other five miRNAs act through yet-to-be-identified targets other than the seven core components of Hh signaling described above. Importantly, through loss-of-function analysis, we found that endogenous miR-10 and miR-958 target fu and smo, respectively, whereas deletion of the other five miRNAs leads to altered expression of Hh signaling components, suggesting that these seven newly discovered miRNAs regulate Hh signaling in vivo. Given the powerful effects of these miRNAs on Hh signaling, we believe that identifying their bona fide targets of the other five miRNAs will help reveal important new players in the Hh regulatory network.

ELOVL2-AS1 inhibits migration of triple negative breast cancer

In this study, we identified a key enhancer RNA (eRNA) region in breast cancer (BRCA) by applying an integrated analysis method. Reported eRNA region and genes affected by them were selected as presumed target pairs. Kaplan-Meier (KM) survival and correlation analyses were performed to screen valuable eRNA region. Based on the KM value and its correlation with the paired target genes, we carefully selected ELOVL2-AS1 as a potential key eRNA region in BRCA. Subsequently, we analyzed the expression of ELOVL2-AS1 and ELOVL2 in four BRCA subtypes and in different BRCA cell lines. The expression of ELOVL2-AS1 and ELOVL2 in triple negative breast cancer (TNBC) was significantly lower than those in Luminal A. After that, we analyzed the function of genes that are positively correlated with ELOVL2-AS1. We found that the co-expression gene mainly related to cilia and cilia characteristics of TNBC is significantly weaker than that of Luminal A. Considering the stronger invasion and metastasis of TNBC (compared with Luminal A) and the close relationship between decreased cilia and metastasis, we overexpressed ELOVL2-AS1 in TNBC and observed its effect on cell migration. The results show that it can inhibit the migration of TNBC. Finally, we analyzed the assay for transposase-accessible chromatin sequencing data, chromatin interaction analysis with paired-end tag sequencing data, and chromatin immunoprecipitation sequencing data and identified the chromatin interaction between ELOVL2-AS1 and ELOVL2, suggesting a direct regulatory interaction.

Suppressive GLI2 fragment enhances liver metastasis in colorectal cancer

Linoleic acid (LA) has been shown to cause inflammation and promote development of colorectal cancer (CRC). Moreover, many literatures show that LA is associated with cancer metastasis. Metastatic cancer cells have high stemness, suggesting that LA might affect the stemness of cancer cells. In this study, we examined the effect of LA on the hedgehog system, which affects cancer stemness. In CT26 cells, LA treatment induced the expression of sonic hedgehog (Shh); the signal transduction factor, and glioma-associated oncogene homolog (Gli)2, whereas the expression of SRY-box transcription factor (Sox)17 was suppressed. Furthermore, LA reduced GLI2 ubiquitination, resulting in an increase in the N-terminal fragment of GLI2, known as suppressive GLI2, produced by cleavage of GLI2. LA-induced cleaved GLI2 was also detected in Colo320 and HT29 human CRC cells. Knocking down Gli2 abrogated the LA-mediated suppression of Sox17 expression. These results suggest that LA promotes tumor cell stemness by increasing of suppressive GLI2 fragments via GLI2 modification. In mouse liver metastasis models, LA enhanced metastasis with production of the suppressive GLI2 fragments in CT26 and HT29 cells, whereas knockdown of GLI2 abrogated LA-induced metastatic activity. In human CRCs, the cases with liver metastasis showed the suppressive GLI2 fragments. This study provides mechanistic insights into LA-induced stemness in colon cancer cells. This finding suggests that dietary intake of LA might increase the stemness of cancer cells and enhance metastatic activity of the cancer.

EN1 Regulates Cell Growth and Proliferation in Human Glioma Cells via Hedgehog Signaling

Glioblastoma is an aggressive cancer of the nervous system that accounts for the majority of brain cancer-related deaths. Through cross-species transcriptome studies, we found that Engrailed 1 (EN1) is highly expressed in serum-free cultured glioma cells as well as glioma tissues, and increased expression level predicts a worse prognosis. EN1 controls glioma cell proliferation, colony formation, migration, and tumorigenic capacity in vivo. It also influences sensitivity of glioma cells to γ-ray irradiation by regulating intracellular ROS levels. Mechanistically, EN1 influences Hedgehog signaling by regulating the level of Gli1 as well as primary cilia length and the primary cilia transport-related protein TULP3. In conclusion, we demonstrate that EN1 acts as an oncogenic regulator that contributes to glioblastoma pathogenesis and could serve as a diagnostic/prognostic marker and therapeutic target for glioblastoma.

High-fat diet intake ameliorates the expression of hedgehog signaling pathway in adult rat liver

BACKGROUND

Disproportionate fatty diet intake provokes hepatic lipid accumulation that causes non-alcoholic fatty liver disease, triggering the embryonically conserved Hedgehog (Hh) pathway in the adult liver. The present study incorporates exploring the impact of chronically administered unsaturated (D-1) and saturated (D-2) fat-enriched diets on hematological parameters, liver functioning, and lipid profile in the rat model. Besides, hepatohistology and real time gene expression analysis of Hh signaling pathway genes i.e., Shh, Ihh, Hhip, Ptch1, Smo, Gli1, Gli2, and Gli3 were carried out.

METHODS AND RESULTS

Fifteen Rattus norvegicus (♂) of 200 ± 25 g weight were grouped into control, D-1, and D-2. Animals were fed on their respective diets for 16 weeks. Fatty diet intake resulted in neutropenia, lymphocytosis, monocytosis, polycythemia, and macrocytosis in both experimental groups. Altered liver injury biomarkers, hypertriglyceridemia, and significantly increased very-low-density lipoprotein VLDL were also noted in both high-fat diet (HFD) groups as compared to control. Hepatohistological examination showed disrupted microarchitecture, infiltration of inflammatory cells, cellular necrosis, widened sinusoidal spaces, and microvesicular steatotic hepatocytes in D-1 and D-2. Collagen deposition in both HFD groups marks the extent of fibrosis. Significant upregulation of hedgehog pathway genes was found in fatty diet groups. In comparison with the control group, Shh Ihh, Hhip, Ptch1, Smo, Gli1, Gli2, and Gli3 were upregulated in D-1. In D-2 Shh, Hhip, and Smo expressions were upregulated, Ihh exhibited downregulation as compared to control.

CONCLUSION

Excess fat deposits in liver due to chronic consumption of high-fat diet results in anomalous architecture and functioning. High-fat diet induced significant variations in Hh pathway genes expression; especially Shh, Ihh, Hhip, Ptch1, Smo, Gli1, Gli2, and Gli3 were upregulated. Infiltration of inflammatory cells ( ), widened sinusoidal spaces (▲), cellular necrosis, and micro vesicular steatotic hepatocytes (*) were shown in the liver. Significant collagen deposition in both HFD groups i.e. D-1 and D-2 confirmed liver fibrosis. Excessive intake of dietary fats impaired normal liver functioning and liver inflammation triggered Hh signaling in adult rats.

Mutations in OSBPL2 cause hearing loss associated with primary cilia defects via Sonic Hedgehog signaling

Defective primary cilia cause a range of diseases called ciliopathies, which include hearing loss (HL). Variants in the human oxysterol-binding protein like 2 (OSBPL2/ORP2) are responsible for autosomal dominant nonsyndromic HL (DFNA67). However, the pathogenesis of OSBPL2 deficiency has not been fully elucidated. In this study, we show that the Osbpl2-KO mice exhibited progressive HL and abnormal cochlear development with defective cilia. Further research revealed that OSBPL2 was located at the base of the kinocilia in hair cells (HCs) and primary cilia in supporting cells (SCs) and functioned in the maintenance of ciliogenesis by regulating the homeostasis of PI(4,5)P₂ (phosphatidylinositol 4,5-bisphosphate) on the cilia membrane. OSBPL2 deficiency led to a significant increase of PI(4,5)P₂ on the cilia membrane, which could be partially rescued by the overexpression of INPP5E. In addition, smoothened and GL13, the key molecules in the Sonic Hedgehog (Shh) signaling pathway, were detected to be downregulated in Osbpl2-KO HEI-OC1 cells. Our findings revealed that OSBPL2 deficiency resulted in ciliary defects and abnormal Shh signaling transduction in auditory cells, which helped to elucidate the underlying mechanism of OSBPL2 deficiency in HL.

Basaloid Follicular Hamartoma of the Eyelid: A Case Report and Literature Review about an Unusual Lesion in the Ocular Region

Basaloid follicular hamartoma (BFH) is a normally benign, uncommon, malformative lesion involving the hair follicles, which usually poses challenges in the differential diagnosis with other benign and malignant tumours, especially basal cell carcinoma, due to significant clinical and morphological overlap. Here, we report the case of a 53-year-old male who presented with a mass in the upper left eyelid evolving for one year. The patient had a previous history of total colectomy and an abdominal desmoid tumour within the context of Familial Adenomatous Polyposis (FAP), with a documented germline mutation in the Adenomatous Polyposis Coli (APC) gene. The eyelid lesion was biopsied and the histological analysis of the three small tissue fragments received revealed fragments with cutaneous–conjunctival lining displaying a subepithelial proliferation of basaloid nests with peripheral palisading, compatible with primitive hair follicles. There were images of anastomosis between different basaloid nests, which had their connection to the epithelial lining preserved. The stroma had high cellularity and sometimes primitive mesenchymal papillae were evident. Pleomorphism was absent, mitotic figures were barely identified, and no necrosis was seen. The basaloid nests did not have epithelial–stromal retraction nor mucin deposits. A diagnosis of BFH was proposed, which was later confirmed after surgical excision of the whole eyelid lesion. No evidence of carcinoma was present. This case illustrates the main features of the rare benign eyelid BFH. The standard medical or surgical approach of these lesions remains to be firmly established. Nearly nine months after surgical excision our patient remains well without signs of disease recurrence.

Metformin exerts anti-tumor effects via Sonic hedgehog signaling pathway by targeting AMPK in HepG2 cells

Metformin, a traditional first-line pharmacologic treatment for type 2 diabetes, has recently been shown to impart anti-cancer effects on hepatocellular carcinoma (HCC). However, the molecular mechanism of metformin on its antitumor activity is still not completely clear. The Sonic hedgehog (Shh) signaling pathway is closely associated with the initiation and progression of HCC. Therefore, the aim of the current study was to investigate the effects of metformin on the biological behavior of HCC and the underlying functional mechanism of metformin on the Shh pathway. The HCC cellular was induced in HepG2 cells by recombinant human Shh (rhShh). The effects of metformin on proliferation and metastasis were evaluated by proliferation, wound healing and invasion assays in vitro. The mRNA and protein expression levels of proteins related to the Shh pathway were measured by western blotting, quantitative PCR and immunofluorescence staining. Metformin inhibited rhShh-induced proliferation and metastasis. Furthermore, metformin decreased mRNA and protein expression of components of the Shh pathway including Shh, Ptch, Smo and Gli-1. Silencing of AMPK in the presence of metformin revealed that metformin could exert its inhibitory effect via AMPK. Our findings demonstrate that metformin can suppress the migration and invasion of HepG2 cells via AMPK-mediated inhibition of the Shh pathway.

The Hedgehog Signaling Pathway in Idiopathic Pulmonary Fibrosis: Resurrection Time

The hedgehog (Hh) pathway is a sophisticated conserved cell signaling pathway that plays an essential role in controlling cell specification and proliferation, survival factors, and tissue patterning formation during embryonic development. Hh signal activity does not entirely disappear after development and may be reactivated in adulthood within tissue-injury-associated diseases, including idiopathic pulmonary fibrosis (IPF). The dysregulation of Hh-associated activating transcription factors, genomic abnormalities, and microenvironments is a co-factor that induces the initiation and progression of IPF.

Surprising genetic and pathological findings in a patient with giant bilateral periadrenal tumours: PEComas and mutations of PTCH1 in Gorlin-Goltz syndrome

Gorlin-Goltz syndrome (GGS) or nevoid basal cell carcinoma syndrome is a rare tumour-overgrowth syndrome associated with multiple developmental anomalies and a wide variety of tumours. Here, we describe a case of a man aged 23 years with GGS with bilateral giant tumours adjacent to both adrenals that raised the suspicion of malignancy on imaging. Histological analysis of both surgically resected tumours revealed perivascular epitheloid cell tumours (PEComas) that were independent of the adrenals. Exome sequencing of the patient’s blood sample revealed a novel germline heterozygous frameshift mutation in the PTCH1 gene. As a second hit, a somatic five nucleotide long deletion in the PTCH1 gene was demonstrated in the tumour DNA of both PEComas. To the best of our knowledge, this is the first report on PEComa in GGS, and this finding also raises the potential relevance of PTCH1 mutations and altered sonic hedgehog signalling in PEComa pathogenesis. The presence of the same somatic mutation in the bilateral tumours might indicate the possibility of a postzygotic somatic mutation that along with the germline mutation of the same gene could represent an intriguing genetic phenomenon (type 2 segmental mosaicism).

Hedgehog Pathway Inhibitors against Tumor Microenvironment

Targeting the hedgehog (HH) pathway to treat aggressive cancers of the brain, breast, pancreas, and prostate has been ongoing for decades. Gli gene amplifications have been long discovered within malignant glioma patients, and since then, inhibitors against HH pathway-associated molecules have successfully reached the clinical stage where several of them have been approved by the FDA. Albeit this success rate implies suitable progress, clinically used HH pathway inhibitors fail to treat patients with metastatic or recurrent disease. This is mainly due to heterogeneous tumor cells that have acquired resistance to the inhibitors along with the obstacle of effectively targeting the tumor microenvironment (TME). Severe side effects such as hyponatremia, diarrhea, fatigue, amenorrhea, nausea, hair loss, abnormal taste, and weight loss have also been reported. Furthermore, HH signaling is known to be involved in the regulation of immune cell maturation, angiogenesis, inflammation, and polarization of macrophages and myeloid-derived suppressor cells. It is critical to determine key mechanisms that can be targeted at different levels of tumor development and progression to address various clinical issues. Hence current research focus encompasses understanding how HH controls TME to develop TME altering and combinatorial targeting strategies. In this review, we aim to discuss the pros and cons of targeting HH signaling molecules, understand the mechanism involved in treatment resistance, reveal the role of the HH pathway in anti-tumor immune response, and explore the development of potential combination treatment of immune checkpoint inhibitors with HH pathway inhibitors to target HH-driven cancers.

Emerging roles of the Hedgehog signalling pathway in inflammatory bowel disease

The Hedgehog (Hh) signalling pathway plays a critical role in the growth and patterning during embryonic development and maintenance of adult tissue homeostasis. Emerging data indicate that Hh signalling is implicated in the pathogenesis of inflammatory bowel disease (IBD). Current therapeutic treatments for IBD require optimisation, and novel effective drugs are warranted. Targeting the Hh signalling pathway may pave the way for successful IBD treatment. In this review, we introduce the molecular mechanisms underlying the Hh signalling pathway and its role in maintaining intestinal homeostasis. Then, we present interactions between the Hh signalling and other pathways involved in IBD and colitis-associated colorectal cancer (CAC), such as the Wnt and nuclear factor-kappa B (NF-κB) pathways. Furthermore, we summarise the latest research on Hh signalling associated with the occurrence and progression of IBD and CAC. Finally, we discuss the future directions for research on the role of Hh signalling in IBD pathogenesis and provide viewpoints on novel treatment options for IBD by targeting Hh signalling. An in-depth understanding of the complex role of Hh signalling in IBD pathogenesis will contribute to the development of new effective therapies for IBD patients.

Mosmo Is Required for Zebrafish Craniofacial Formation

Hedgehog (Hh) signaling is a highly regulated molecular pathway implicated in many developmental and homeostatic events. Mutations in genes encoding primary components or regulators of the pathway cause an array of congenital malformations or postnatal pathologies, the extent of which is not yet fully defined. Mosmo (Modulator of Smoothened) is a modulator of the Hh pathway, which encodes a membrane tetraspan protein. Studies in cell lines have shown that Mosmo promotes the internalization and degradation of the Hh signaling transducer Smoothened (Smo), thereby down-modulating pathway activation. Whether this modulation is essential for vertebrate embryonic development remains poorly explored. Here, we have addressed this question and show that in zebrafish embryos, the two mosmo paralogs, mosmoa and mosmob, are expressed in the head mesenchyme and along the entire ventral neural tube. At the cellular level, Mosmoa localizes at the plasma membrane, cytoplasmic vesicles and primary cilium in both zebrafish and chick embryos. CRISPR/Cas9 mediated inactivation of both mosmoa and mosmob in zebrafish causes frontonasal hypoplasia and craniofacial skeleton defects, which become evident in the adult fish. We thus suggest that MOSMO is a candidate to explain uncharacterized forms of human congenital craniofacial malformations, such as those present in the 16p12.1 chromosomal deletion syndrome encompassing the MOSMO locus.

Patidegib in Dermatology: A Current Review

Background: Basal cell carcinoma is one of the most common types of non-melanoma skin cancers, which can be locally destructive despite low-rate metastasis. Surgery is the treatment of choice, but it lacks of efficacy on advanced cases. Hedgehog pathway inhibitors are a class of drugs providing a new therapeutic option for patients affected by advanced disease. Besides systemic therapy, such as vismodegib and sonidegib, also topical inhibitors have been developed. Patidegib is able to decrease tumor burden, reducing the adverse effects induced by systemic targeted therapies. Methods: We performed comprehensive research to summarize the use of patidegib in advanced and recurrent aggressive basal cell carcinomas. Only English language human studies were included in the search. Results: Seven trials reported the application of patidegib. Both topical and systemic patidegib demonstrated safety, tolerability, and efficacy in naïve patients with stage II and III basal cell carcinomas, while stage IV disease and not-naïve patients did not show any benefit. Conclusion: Unlike systemic Hedgehog pathway inhibitors, patidegib 2% gel is not associated with systemic adverse effects and allows a better patient management. Considering the multidisciplinary management of neoplasia, in the era of precision medicine, it is mandatory to confide in pharmacogenomics to obtain personalized combined or sequential therapies.

The Role of the Hedgehog Pathway in Cholangiocarcinoma

Simple Summary

Cholangiocarcinoma (CCA) is one of the most refractory malignancies with a high mortality rate. Among all the pathways involved in CCA development, emerging evidence highlights Hedgehog (HH) signaling as a substantial player in CCA-genesis and development. The pro-tumoral function of HH provides potential therapeutic implications, and recently the use of HH inhibitors has paved the way for clinical application in various solid tumors. Targeting HH members, namely Hedgehog ligands, SMO transmembrane protein and GLI transcription factors may thus confer therapeutic options for the improvement of CCA treatment outcome.

Abstract

Cholangiocarcinoma (CCA) is a poorly treatable type of cancer and, along with hepatocellular carcinoma (HCC), is the predominant type of primitive liver cancer in adults. The lack of understanding of CCA biology has slowed down the identification of novel targets and the development of effective treatments. While tumors share some general characteristics, detailed knowledge of specific features is essential for the development of effectively tailored therapeutic approaches. The Hedgehog (HH) signaling cascade regulates stemness biology, embryonal development, tissue homeostasis, and cell proliferation and differentiation. Its aberrant activation has been associated with a variety of solid and hematological human malignancies. Several HH-inhibiting compounds have been indeed developed as potential anticancer agents in different types of tumors, with Smoothened and GLI inhibitors showing the most promising results. Beside its well-established function in other tumors, findings regarding the HH signaling in CCA are still controversial. Here we will give an overview of the most important clinical and molecular features of cholangiocarcinoma, and we will discuss the available evidence of the crosstalk between the HH signaling pathway and the cholangiocarcinoma cell biology.

Genomic Biomarkers of Meningioma: A Focused Review

Meningiomas represent a phenotypically and genetically diverse group of tumors which often behave in ways that are not simply explained by their pathologic grade. The genetic landscape of meningiomas has become a target of investigation as tumor genomics have been found to impact tumor location, recurrence risk, and malignant potential. Additionally, targeted therapies are being developed that in the future may provide patients with personalized chemotherapy based on the genetic aberrations within their tumor. This review focuses on the most common genetic mutations found in meningiomas of all grades, with an emphasis on the impact on tumor location and clinically relevant tumor characteristics. NF-2 and the non-NF-2 family of genetic mutations are summarized in the context of low-grade and high-grade tumors, followed by a comprehensive discussion regarding the genetic and embryologic basis for meningioma location and phenotypic heterogeneity. Finally, targeted therapies based on tumor genomics currently in use and under investigation are reviewed and future avenues for research are suggested. The field of meningioma genomics has broad implications on the way meningiomas will be treated in the future, and is gradually shifting the way clinicians approach this diverse group of tumors.

The Role of Sonic Hedgehog in Human Holoprosencephaly and Short-Rib Polydactyly Syndromes

The Hedgehog (HH) signalling pathway is one of the major pathways controlling cell differentiation and proliferation during human development. This pathway is complex, with HH function influenced by inhibitors, promotors, interactions with other signalling pathways, and non-genetic and cellular factors. Many aspects of this pathway are not yet clarified. The main features of Sonic Hedgehog (SHH) signalling are discussed in relation to its function in human development. The possible role of SHH will be considered using examples of holoprosencephaly and short-rib polydactyly (SRP) syndromes. In these syndromes, there is wide variability in phenotype even with the same genetic mutation, so that other factors must influence the outcome. SHH mutations were the first identified genetic causes of holoprosencephaly, but many other genes and environmental factors can cause malformations in the holoprosencephaly spectrum. Many patients with SRP have genetic defects affecting primary cilia, structures found on most mammalian cells which are thought to be necessary for canonical HH signal transduction. Although SHH signalling is affected in both these genetic conditions, there is little overlap in phenotype. Possible explanations will be canvassed, using data from published human and animal studies. Implications for the understanding of SHH signalling in humans will be discussed.

Cancer Stem Cells and their Management in Cancer Therapy

BACKGROUND

In the last decade, the proposed Cancer Stem Cell (CSC) hypothesis has steadily changed the way cancer treatment is approached. CSCs may be the source of the heterogeneous non-tumorigenic cell population included in a neoplasm. Intratumor and intertumoral heterogeneity is a well-known phenomenon that massively entangles the diagnosis and treatment of cancer. The literature seems to suggest that heterogeneity develops progressively within tumor-initiating stem cells. CSCs harbor genetic and/or epigenetic alterations that allow them to differentiate into multiple tumor cell types sequentially.

OBJECTIVE

The CSC hypothesis, cellular therapy, and the most recent patents on CSCs were reviewed.

METHODS

PubMed, Scopus, and Google Scholar were screened for this information. Also, an analysis of the most recent data targeting CSCs in pediatric cancer developed at two Canadian institutions is provided. The genes involved with the activation of CSCs and the drugs used to antagonize them are also highlighted.

RESULTS

It is underlined that (1) CSCs possess stem cell-like properties, including the ability for self-renewal; (2) CSCs can start carcinogenesis and are responsible for tumor recurrence after treatment; (3) Although some limitations have been raised, which may oppose the CSC hypothesis, cancer progression and metastasis have been recognized to be caused by CSCs.

CONCLUSION

The significant roles of cell therapy may include an auto-transplant with high-dose treatment, an improvement of the immune function, creation of chimeric antigen receptor T cells, and the recruitment of NK cell-based immunotherapy.

Connexin 43 and Sonic Hedgehog Pathway Interplay in Glioblastoma Cell Proliferation and Migration

Simple Summary

Glioblastoma is the product of accumulated genetic and epigenetic alteration where tumor cells support each other through cellular communication mechanisms and deregulated signalling processes. The autocrine and paracrine pathways between the intracellular and extracellular milieu is mediated by connexin 43, the main gap junction-forming protein driving glioblastoma progression. In this scenario, sonic hedgehog pathway, a key deregulated pathway involved in cell network signalling may affect connexin 43 expression, promoting glioblastoma pathobiology. In this study, we sought to explore how the modulation of the sonic hedgehog affects connexin 43 inducing glioblastoma hallmarks. To do this we evaluated biological effects of sonic hedgehog pathway modulation by purmorphamine and cyclopamine, a smoothened agonist and antagonist, respectively. We revealed that cell migration and proliferation are associated with connexin 43 expression upon sonic hedgehog modulation. Our study suggests that sonic hedgehog and connexin 43 axis may represent a potential therapeutic strategy for glioblastoma.

Abstract

Glioblastoma (GBM) represents the most common primary brain tumor within the adult population. Current therapeutic options are still limited by high rate of recurrences and signalling axes that promote GBM aggressiveness. The contribution of gap junctions (GJs) to tumor growth and progression has been proven by experimental evidence. Concomitantly, tumor microenvironment has received increasing interest as a critical process in dysregulation and homeostatic escape, finding a close link between molecular mechanisms involved in connexin 43 (CX43)-based intercellular communication and tumorigenesis. Moreover, evidence has come to suggest a crucial role of sonic hedgehog (SHH) signalling pathway in GBM proliferation, cell fate and differentiation. Herein, we used two human GBM cell lines, modulating SHH signalling and CX43-based intercellular communication in in vitro models using proliferation and migration assays. Our evidence suggests that modulation of the SHH effector smoothened (SMO), by using a known agonist (i.e., purmorphamine) and a known antagonist (i.e., cyclopamine), affects the CX43 expression levels and therefore the related functions. Moreover, SMO activation also increased cell proliferation and migration. Importantly, inhibition of CX43 channels was able to prevent SMO-induced effects. SHH pathway and CX43 interplay acts inducing tumorigenic program and supporting cell migration, likely representing druggable targets to develop new therapeutic strategies for GBM.

A systematic summary of survival and death signalling during the life of hair follicle stem cells

Hair follicle stem cells (HFSCs) are among the most widely available resources and most frequently approved model systems used for studying adult stem cells. HFSCs are particularly useful because of their self-renewal and differentiation properties. Additionally, the cyclic growth of hair follicles is driven by HFSCs. There are high expectations for the use of HFSCs as favourable systems for studying the molecular mechanisms that contribute to HFSC identification and can be applied to hair loss therapy, such as the activation or regeneration of hair follicles, and to the generation of hair using a tissue-engineering strategy. A variety of molecules are involved in the networks that critically regulate the fate of HFSCs, such as factors in hair follicle growth and development (in the Wnt pathway, Sonic hedgehog pathway, Notch pathway, and BMP pathway), and that suppress apoptotic cues (the apoptosis pathway). Here, we review the life cycle, biomarkers and functions of HFSCs, concluding with a summary of the signalling pathways involved in HFSC fate for promoting better understanding of the pathophysiological changes in the HFSC niche. Importantly, we highlight the potential mechanisms underlying the therapeutic targets involved in pathways associated with the treatment of hair loss and other disorders of skin and hair, including alopecia, skin cancer, skin inflammation, and skin wound healing.