Progress and future prospective of FDG-PET/CT imaging combined with optimized procedures in lung cancer: toward precision medicine

With a 5-year overall survival of approximately 20%, lung cancer has always been the number one cancer-specific killer all over the world. As a fusion of positron emission computed tomography (PET) and computed tomography (CT), PET/CT has revolutionized cancer imaging over the past 20 years. In this review, we focused on the optimization of the function of ¹⁸F-flurodeoxyglucose (FDG)-PET/CT in diagnosis, prognostic prediction and therapy management of lung cancers by computer programs. FDG-PET/CT has demonstrated a surprising role in development of therapeutic biomarkers, prediction of therapeutic responses and long-term survival, which could be conducive to solving existing dilemmas. Meanwhile, novel tracers and optimized procedures are also developed to control the quality and improve the effect of PET/CT. With the continuous development of some new imaging agents and their clinical applications, application value of PET/CT has broad prospects in this area.

IL-24 Inhibits Lung Cancer Growth by Suppressing GLI1 and Inducing DNA Damage

Aberrant expression of GLI1 is responsible for aggressive tumor behavior and survival due to its effects on the DNA damage response (DDR). We investigated whether interleukin (IL)-24, a tumor suppressor, inhibits GLI1 and the associated DDR pathway in human NSCLCs. IL-24 treatment reduces mRNA and protein expression of GLI1 in lung tumor cells, but not in normal cells. GLI1 reporter assay and mRNA studies demonstrated that IL-24 regulates GLI1 at the post-transcriptional level by favoring mRNA degradation. Associated with GLI1 inhibition was marked suppression of the ATM-mediated DDR pathway resulting in increased DNA damage, as evidenced by γ-H2AX foci and Comet assay. Furthermore, attenuation of GLI1-associated DDR by IL-24 increased caspase-3 and PARP activity, resulting in cancer cell apoptosis. GLI1 inhibition and overexpression confirmed that IL-24-mediated anti-tumor effects involved the GLI-dependent pathway. Finally, we observed that IL-24-mediated alteration in GLI1 is independent of the canonical hedgehog-signaling pathway. Our study provides evidence that IL-24 treatment induces DNA damage, and reduces GLI1 expression and offers an opportunity for testing IL-24-based therapy for inhibiting GLI1 in lung cancer.

Defining aggressive or early progressing nononcogene-addicted non-small-cell lung cancer: a separate disease entity?

A substantial proportion of patients with nononcogene-addicted non-small-cell lung cancer (NSCLC) has 'aggressive disease', as reflected in short time to progression or lack of disease control with initial platinum-based chemotherapy. Recently, clinical correlates of aggressive disease behavior during first-line therapy have been shown to predict greater benefit from addition of nintedanib to second-line docetaxel in adenocarcinoma NSCLC. Positive predictive effects of aggressive disease have since been reported with other anti-angiogenic agents (ramucirumab and bevacizumab), while such features may negatively impact on outcomes with nivolumab in nonsquamous NSCLC with low PD-L1 expression. Based on a review of the clinical data, we recommend aggressive nonsquamous NSCLC should be defined by progression within <6-9 months of first-line treatment initiation.

IL-24 modulates the high mobility group (HMG) A1/miR222 /AKT signaling in lung cancer cells

Interleukin (IL)-24, a novel tumor suppressor/cytokine exhibits antitumor activity against a broad-spectrum of human cancer cells. In a recent study, we showed that IL-24 inhibited AKT in lung cancer cells. However, the molecular mechanism of AKT inhibition by IL-24 remains elusive.The high mobility group (HMG) A1 a member of the non-histone chromosomal proteins and commonly referred to as architectural transcription factor, regulates transcription of various genes involved in cell growth and survival. Overexpression of HMGA1 has been shown to be associated with tumor progression and metastasis in several cancers, including human lung cancer. A recent study demonstrated that HMGA1 activates AKT function by reducing the activity of the protein phosphatase, phosphatase 2A subunit B (PPP2R2A) via the oncogenic micro (mi) RNA-222. Based on this report we hypothesized that IL-24-mediated AKT inhibition involved the HMGA1/miR-222 axis.To test our hypothesis, in the present study we used a H1299 lung cancer cell line that expressed exogenous human IL-24 when induced with doxycycline (DOX). Induction of IL-24 expression in the tumor cells markedly reduced HMGA1 mRNA and protein levels. Using a mechanistic approach, we found that IL-24 reduced miR-222-3p and -5p levels, as determined by qRT-PCR. Associated with HMGA1 and miR-222 inhibition was a marked increase in PPP2R2A, with a concomitant decrease in phosphorylated AKTT308/S473 expression. SiRNA-mediated knockdown of HMGA1 in combination with IL-24 significantly reduced AKT T308/S473 protein expression and greatly reduced cell migration and invasion compared with individual treatments. Further combination of IL-24 and a miR-222-3p inhibitor significantly increased PPP2R2A expression.Our results demonstrate for the first time that IL-24 inhibits AKT via regulating the HMGA1/miR-222 signaling node in human lung cancer cells and acts as an effective tumor suppressor. Thus, a therapy combining IL-24 with HMGA1 siRNA or miR-222-3p inhibitor should present effective treatment of lung cancer.

Thyroid transcription factor-1 expression in advanced non- small cell lung cancer: impact on survival outcome

BACKGROUND

The prognostic role of thyroid transcription factor-1 (TTF-1) expression in lung cancer has been assessed but with inconsistent results. The present study aimed to evaluate the prognostic value of TTF1 expression in advanced non-squamous non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

In this retrospective study, patients with stage IIIB-IV non-squamous NSCLC were enrolled. Progression free survival (PFS) and overall survival (OS) were assessed according to TTF1 expression status, age categories (≤60 vs >60 years), gender, performance status (PS) (0-2 vs 3-4), type of 1st line chemotherapy (pemetrexed containing vs others) and EGFR status.

RESULTS

A total of 120 patients were included. In univariate analysis, PFS was improved in patients with PS 0-2 (7.0 vs 2.0 months, p=0.002) and those who received pemetrexed-containing chemotherapy (9.2 vs 5.8 months, p=0.004). OS was improved in female patients (23.0 vs 8.7 months, p<0.0001), PS 0-2 (14.4 vs 2.0 months, p<0.0001), those with pemetrexed-containing chemotherapy (17.0 vs 11.0 months, p=0.019), TTF1-positive (12.8 vs 5.8 months, p=0.011) and EGFR- mutant patients (23.0 vs 11.7 months, p=0.006). In multivariate analysis, male gender (HR=2.34, p=0.025) and non-pemetrexed containing therapy (HR=2.24, p=0.022) were independent predictors of worse PFS. Wild EGFR status (HR=2.49, p=0.015) and male gender (HR=2.78, p=0.008) were predictors of worse OS.

CONCLUSIONS

Pemetrexed-containing therapy significantly improved PFS while OS was improved in EGFR mutant patients. Female patients had better PFS and OS. TTF1 expression was not a prognostic marker in advanced non-squamous NSCLC.