Tight Junctions and Cancer: Targeting Claudin-1 and Claudin-4 in Thyroid Pathologies.

Purpose: Claudins are tight junction proteins partaking in epithelial-mesenchymal transition and cancer progression. In this study, we investigated the expression patterns of claudin-1 and claudin-4 in thyroid pathologies, discussed their links with the pathogenesis of thyroid cancers, and reviewed the therapeutic potential of targeting claudins in cancers. Methods: The research group 162 cores of thyroid samples from patients (70 female and 11 male) diagnosed with thyroid adenoma, goiter, papillary, medullary, and anaplastic thyroid cancers. All samples were stained for the expression of claudin-1 and claudin-4, and the analysis of IHC was performed. Results: Goiter samples showed negative claudin-1 and mostly positive expression of claudin-4. Papillary thyroid cancer and thyroid adenoma showed positive expression of claudin-1, while claudin-4 was positive in papillary thyroid cancers, goiters, and adenomas. In The Cancer Genome Atlas cohort, claudin-1 and claudin-4 were overexpressed in papillary thyroid cancer compared to normal thyroid tissues. Patients with high claudin-1 expression had significantly lower 5-year overall survival than patients with low claudin-1 levels (86.75% vs. 98.65, respectively). In multivariate analysis, high claudin-1 expression (HR 7.91, CI 95% 1.79-35, p = 0.006) and advanced clinical stage remained statistically significant prognostic factors of poor prognosis in papillary thyroid cancer. Conclusions: The pattern of claudin-1 staining was pathology-specific and changed between cancers of different histology. This phenomenon may be associated with the different pathogenesis of thyroid cancers and early metastasis. The loss of claudin-1 and claudin-4 characterized more aggressive cancers. Several studies have shown the benefits of targeting claudins in cancers, but their implementation into clinical practice requires further trials.

PCMT1 as a prognostic marker in breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) is one of the most aggressive cancers in women, therefore it is necessary to determine novel prognostic markers to estimate survival and advancement the treatment of the disease. Recently, PCMT1, a protein mediating TNBC immune infiltration, has gained attention as a potential therapeutic target. The aim of the study was to demonstrate the relationship between PCMT1 protein overexpression as a prognostic indicator for patients with TNBC cancer and patient survival. MATERIALS AND METHODS: The study included 64 samples collected from 64 TNBC patients. We used the ImageJ software with the IHC Profiler driver for image analysis. To improve the reliability of the results, we expanded the analysis by including The Cancer Genome Atlas cohort. RESULTS: We observed strong PCMT1 immunoreactivity in breast cancer samples and PCMT1 expression in TNBC was significantly higher than in the control group. Patients with high PCMT1 expression had a significantly lower overall survival rate (60.62% vs. 90.35%, respectively) than patients with low PCMT1 expression. In our study and TCGA groups, PCMT1 expression did not correlate with lymph node involvement and distant metastases but correlated with tumor stage. The results obtained in a larger TCGA group are consistent with those in our research group. Overexpression of PCMT1 was a prognostic marker of shorter survival in patients with TNBC. CONCLUSIONS: The overexpression of the PCMT1 protein in triple negative breast cancer significantly correlated with shorter overall survival. The confirmed association could be a potential prognostic biomarker for patients with TNBC.

SARS-CoV-2 Infection during Delivery Causes Histopathological Changes in the Placenta.

BACKGROUND: SARS-CoV-2 can damage human placentas, leading to pregnancy complications, such as preeclampsia and premature birth. This study investigates the histopathological changes found in COVID-19-affected placentas. MATERIALS AND METHODS: This study included 23 placentas from patients with active COVID-19 during delivery and 22 samples from patients without COVID-19 infection in their medical history. The samples underwent histopathological examination for pathology, such as trophoblast necrosis, signs of vessel damage, or fetal vascular malperfusion. RESULTS: Newborns from the research group have lower weights and Apgar scores than healthy newborns. In the COVID-19 group, calcifications and collapsed intervillous space were more frequent, and inflammation was more severe than in the healthy group. At the same time, the placenta of SARS-CoV-2-positive patients showed signs of accelerated vascular maturation. Trophoblast necrosis was found only in the placentas of the research group. The expression of CD68+ was elevated in the COVID-19 cohort, suggesting that macrophages constituted a significant part of the inflammatory infiltrate. The increase in lymphocyte B markers was associated with placental infarctions, while high levels of CD3+, specific for cytotoxic T lymphocytes, correlated with vascular injury. CONCLUSIONS: SARS-CoV-2 is associated with pathological changes in the placenta, including trophoblast necrosis, calcification, and accelerated villous maturation. Those changes appear to be driven by T cells and macrophages, whose increased expression reflects ongoing histiocytic intervillositis in the placenta.

The role of IL-17 in the pathogenesis and treatment of glioblastoma-an update on the state of the art and future perspectives.

Glioblastoma (GBM) is the most common malignant brain tumor, which, despite significant progress made in the last years in the field of neuro-oncology, remains an incurable disease. GBM has a poor prognosis with a median survival of 12-15 months, and its aggressive clinical course is related to rapid growth, extensive infiltration of adjacent tissues, resistance to chemotherapy, radiotherapy and immunotherapy, and frequent relapse. Currently, several molecular biomarkers are used in clinical practice to predict patient prognosis and response to treatment. However, due to the overall unsatisfactory efficacy of standard multimodal treatment and the remaining poor prognosis, there is an urgent need for new biomarkers and therapeutic strategies for GBM. Recent evidence suggests that GBM tumorigenesis is associated with crosstalk between cancer, immune and stromal cells mediated by various cytokines. One of the key factors involved in this process appears to be interleukin-17 (IL-17), a pro-inflammatory cytokine that is significantly upregulated in the serum and tissue of GBM patients. IL-17 plays a key role in tumorigenesis, angiogenesis, and recurrence of GBM by activating pro-oncogenic signaling pathways and promoting cell survival, proliferation, and invasion. IL-17 facilitates the immunomodulation of the tumor microenvironment by promoting immune cells infiltration and cytokine secretion. In this article we review the latest scientific reports to provide an update on the role of IL-17 role in tumorigenesis, tumor microenvironment, diagnosis, prognosis, and treatment of GBM.

High MAL2 expression predicts shorter survival in women with triple-negative breast cancer.

INTRODUCTION: Due to its lack of conventional surface receptors, triple-negative breast cancer (TNBC) is inherently resistant to most targeted therapies. MAL2 overexpression prompts endocytosis, conferring resistance to novel therapeutics. This study explores the role of MAL2 and PD-L1 in TNBC patients' prognosis. METHODS: We performed immunohistochemical analysis on 111 TNBC samples collected from 76 patients and evaluated the expression of MAL2 and PD-1. We expanded the study by including The Cancer Genome Atlas (TCGA) cohort. RESULTS: MAL2 expression did not correlate with stage, grade, tumor size, lymph node invasion, metastasis, and PD-1 expression. Patients with high MAL2 had significantly lower 5-year survival rates (71.33% vs. 89.59%, p = 0.0224). In the tissue microarray cohort (TMA), node invasions, size, recurrence, and low MAL2 (HR 0.29 [CI 95% 0.087-0.95]; p < 0.05) predicted longer patients' survival. In the TCGA cohort, patients with low MAL2 had significantly longer overall survival and disease-specific survival than patients with high MAL2. Older age and high MAL2 expression were the only independent predictors of shorter patient survival in the BRCA TCGA cohort. CONCLUSION: High MAL2 predicts unfavorable prognosis in triple-negative breast cancer, and its expression is independent of PD-1 levels and clinicopathological features of TNBC.

Targeting apoptosis in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cancer, accounting for approximately 80% of all renal cell cancers. Due to its exceptional inter- and intratumor heterogeneity, it is highly resistant to conventional systemic therapies. Targeting the evasion of cell death, one of cancer's hallmarks, is currently emerging as an alternative strategy for ccRCC. In this article, we review the current state of apoptosis-inducing therapies against ccRCC, including antisense oligonucleotides, BH3 mimetics, histone deacetylase inhibitors, cyclin-kinase inhibitors, inhibitors of apoptosis protein antagonists, and monoclonal antibodies. Although preclinical studies have shown encouraging results, these compounds fail to improve patients' outcomes significantly. Current evidence suggests that inducing apoptosis in ccRCC may promote tumor progression through apoptosis-induced proliferation, anastasis, and apoptosis-induced nuclear expulsion. Therefore, re-evaluating this approach is expected to enable successful preclinical-to-clinical translation.

Atypical Presentation of Bronchogenic Cyst in the Retroperitoneal Space.

Bronchogenic cysts, benign congenital malformations resulting from abnormal tracheobronchial tree budding, primarily manifest in the mediastinum, with retroperitoneal occurrence being exceedingly rare. Typically incidental findings on imaging, and their diagnosis pose challenges, particularly when malignancy is suspected. We present a case involving a 55-year-old woman diagnosed with chronic back pain. Physical examination revealed a painful mass in the left renal region. Subsequent MRI identified a smooth mass in the left adrenal gland without infiltration of surrounding structures. Laparoscopic surgery successfully removed the lesion without complications. Pathomorphological examination confirmed a gelatinous-filled cyst, identified as a retroperitoneal bronchogenic cyst in the left adrenal gland. Increasing reports of retroperitoneal bronchogenic cysts contribute to a better understanding of their characteristics, aiding preoperative diagnosis. However, given potential malignancy and definitive diagnosis through histopathological examination, surgical resection remains the preferred method.

Mechanisms of SARS-CoV-2 Placental Transmission.

The widespread occurrence of SARS-CoV-2 infections and the diverse range of symptoms have placed significant strain on healthcare systems worldwide. Pregnancy has also been affected by COVID-19, with an increased risk of complications and unfavorable outcomes for expectant mothers. Multiple studies indicate that SARS-CoV-2 can infiltrate the placenta, breach its protective barrier, and infect the fetus. Although the precise mechanisms of intrauterine transmission remain unclear, factors such as perinatal infection, macrophages, sexual intercourse, and the virus' interaction with host angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP-1) proteins appear to play a role in this process. The integrity of the placental barrier fluctuates throughout pregnancy and appears to influence the likelihood of fetal transmission. The expression of placental cell receptors, like ACE2, changes during pregnancy and in response to placental damage. However, due to the consistent presence of others, such as NRP-1, SARS-CoV-2 may potentially enter the fetus at different stages of pregnancy. NRP-1 is also found in macrophages, implicating maternal macrophages and Hofbauer cells as potential routes for viral transmission. Our current understanding of SARS-CoV-2's vertical transmission pathways remains limited. Some researchers question the ACE2-associated transmission model due to the relatively low expression of ACE2 in the placenta. Existing studies investigating perinatal transmission and the impact of sexual intercourse have either involved small sample sizes or lacked statistical significance. This review aims to explore the current state of knowledge regarding the potential mechanisms of COVID-19 vertical transmission, identifying areas where further research is needed to fill the gaps in our understanding.

Targeting circulating tumor cells to prevent metastases.

Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor, enter the bloodstream or body fluids, and spread to other body parts, leading to metastasis. Their presence and characteristics have been linked to cancer progression and poor prognosis in different types of cancer. Analyzing CTCs can offer valuable information about tumors' genetic and molecular diversity, which is crucial for personalized therapy. Epithelial-mesenchymal transition (EMT) and the reverse process, mesenchymal-epithelial transition (MET), play a significant role in generating and disseminating CTCs. Certain proteins, such as EpCAM, vimentin, CD44, and TGM2, are vital in regulating EMT and MET and could be potential targets for therapies to prevent metastasis and serve as detection markers. Several devices, methods, and protocols have been developed for detecting CTCs with various applications. CTCs interact with different components of the tumor microenvironment. The interactions between CTCs and tumor-associated macrophages promote local inflammation and allow the cancer cells to evade the immune system, facilitating their attachment and invasion of distant metastatic sites. Consequently, targeting and eliminating CTCs hold promise in preventing metastasis and improving patient outcomes. Various approaches are being explored to reduce the volume of CTCs. By investigating and discussing targeted therapies, new insights can be gained into their potential effectiveness in inhibiting the spread of CTCs and thereby reducing metastasis. The development of such treatments offers great potential for enhancing patient outcomes and halting disease progression.

Refining PD-1/PD-L1 assessment for biomarker-guided immunotherapy: A review.

Anti-programmed cell death ligand 1 (anti-PD-L1)  immunotherapy is an increasingly crucial in cancer treatment. To date, the Federal Drug Administration (FDA) has approved four PD-L1 immunohistochemistry (IHC) staining protocols, commercially available in the form of "kits", facilitating testing for PD-L1 expression. These kits comprise four PD-L1 antibodies on two separate IHC platforms, each utilizing distinct, non-interchangeable scoring systems. Several factors, including tumor heterogeneity and the size of the tissue specimens assessed, can lead to PD-L1 status misclassification, potentially hindering the initiation of therapy. Therefore, the development of more accurate predictive biomarkers to distinguish between responders and non-responders prior to anti-PD-1/PD-L1 therapy warrants further research. Achieving this goal necessitates refining sampling criteria, enhancing current methods of PD-L1 detection, and deepening our understanding of the impact of additional biomarkers. In this article, we review potential solutions to improve the predictive accuracy of PD-L1 assessment in order to more precisely anticipate patients' responses to anti-PD-1/PD-L1 therapy, monitor disease progression and predict clinical outcomes.

Flow cytometry in the detection of circulating tumor cells in neoplastic effusions.

PURPOSE: Despite its limitations, the cytology of body fluids is widely used in diagnosing neoplastic cells. Flow cytometry detects and identifies individual cells, enabling the detection of circulating tumor cells and facilitating diagnosis. This study compared the diagnostic utility of flow cytometry and cytology for detecting cancer cells in peritoneal and pleural fluids. METHODOLOGY: We used flow cytometry and cytology to examine 119 pleural and peritoneal effusions received for routine screening. Antibodies against clusters of differentiation 45 (CD45), 14 (CD14), and Epithelial cell adhesion molecule (EpCAM) were used to detect malignant cells. Based on combined clinical and diagnostic information, 37 fluid specimens were malignant, and 77 were benign. RESULTS: Flow cytometry correctly identified 34 cancers, while cytology identified 26 cancers (sensitivity 91.89 % vs. 70.27, respectively). Both methods had equal specificity (98.7 %). At a cut-off of > 0.29 % EpCAM(+) cells to all cells in the samples, flow cytometry accurately detected cancer cells, achieving 89.2 % sensitivity, 90.9 % specificity, and an AUC of 0.959 (p < 0.001). CONCLUSION: Flow cytometry improves the detection of epithelial cancer cells in peritoneal and pleural fluids compared to conventional cytology. Due to similar specificity and higher sensitivity, flow cytometry offers a promising alternative to cytology for patient screening.

Diagnostic biopsy does not accurately reflect the PD-L1 expression in triple-negative breast cancer.

PD-L1 expression is known to predict the benefits of immune checkpoint inhibitor therapy for triple-negative breast cancer (TNBC). We examined whether the PD-L1 expression evaluated in biopsy specimens accurately reflects its expression in the whole tumor. Immunohistochemistry was performed on 81 biopsy and resection specimens from patients with TNBC to determine their PD-L1 status. We found PD-L1-positive tumors in 23 (28%) biopsy specimens and primarily PD-L1-negative tumors in 58 (72%). The PD-L1 status was reevaluated in matching postoperative specimens of primarily PD-L1-negative tumors. Of them, 31% (18/58) were positive, whereas 69% (40/58) were negative. Considering the pre- and postoperative analyses, 41 (51%) patients had PD-L1-positive tumors, while 40 had PD-L1-negative tumors. We found 18 (22%) more PD-L1-positive tumors while examining the resection specimens compared to biopsies, and the difference was statistically significant (p = 0.0038). Diagnostic biopsies do not fully reflect the PD-L1 expression in TNBC. Our results suggest that a significant subset of TNBC patients may be misclassified as PD-L1-negative and disqualified from anti-PD-L1 therapy.

The prognostic role of p53 and its correlation with CDK9 in urothelial carcinoma.

PURPOSE: The mutation of p53 is considered a pivotal step in bladder cancer pathogenesis. Recently, distinct interactions between p53 and CDK9, a transcription regulator, have been described. In this work, we explored the prognostic role of p53 expression and evaluated its associations with CDK9 in urothelial carcinoma. MATERIALS AND METHODS: The research group consisted of 67 bladder cancer samples and 32 normal urothelial mucosa samples. All specimens were analyzed using ImageJ and the IHC profiler plugin. To validate the results, 406 cases from The Cancer Genome Atlas database were analyzed. RESULTS: P53 and CDK9 are overexpressed in urothelial cancer tissues when compared to normal urothelial tissues (p < 0.05). High p53 expression was observed in metastatic tumors and tumors with high CDK9 expression (p < 0,05). High p53 expression was predictive for shorter survival in patients with non-muscle-invasive bladder cancer (HR = 0.107 [0.012-0.96]; p = 0.046) but did not correlate with prognosis in the muscle-invasive group. In high CDK9 cancers, high p53 expression correlated with the occurrence of high-grade and muscle-invasive tumors (p < 0.05). CONCLUSION: High expression of p53 correlates with unfavorable clinical features of bladder cancer. CDK9 is associated with the expression of p53, possibly through interactions with p53 inhibitors. Since the blockade of CDK9 in other malignancies reactivates wild-p53 activity, confirming the crosstalk between p53 and CDK9 in bladder cancer may be another step to explain the mechanism of tumor progression in its early stages.

Assessment of immunomodulation and regulation of cell cycle in epithelium and stroma after Cidofovir injection in patients with recurrent respiratory papillomatosis-Pilot study.

Recurrent respiratory papillomatosis is strictly connected with human papillomavirus (HPV) infection of the epithelium of the upper respiratory tract. The main treatment of lesions located in the larynx or lower pharynx includes microsurgical excision by using a CO2 laser. To decrease the amount of surgical procedures gain in importance combined therapy with antiviral agents. The aim of this study was to investigate the effect of the intralesional application of Cidofovir on the tissue of laryngeal papillomas. We have shown that simultaneous microsurgery with adjuvant therapy of Cidofovir reduces chronic inflammation (by measuring the expression of CD4 and CD8 in tissue samples), cell proliferation, and regulates the cell cycle of HPV-infected cells by reducing the expression of p53 and p63 proteins. In addition, this strategy reduces the multiple surgical procedures and regrowth of the pathology.

TOLLIP Protein Expression Predicts Unfavorable Outcome in Renal Cell Carcinoma.

Resistance to systemic therapy is one of the hallmarks of renal cell carcinoma (RCC). Recently, TOLLIP has emerged as a possible driver of autophagy and chemoresistance. We explored the relationship between primary and metastatic RCC tumor characteristics, patient survival, and TOLLIP expression. The tissue microarrays cohort contained 95 cores of the primary tumor, matched metastases, and matched adjacent tissues derived from 32 RCC patients. TOLLIP expression in tumor samples was evaluated using the H-score. All examined samples showed cytoplasmic TOLLIP expression, with a median value of 100 in primary tumors, 107.5 in metastases, and 220 in the control group. The expression was significantly higher in the normal adjacent tissues compared to primary or metastatic RCC (p < 0.05). We found a positive correlation between expressions of TOLLIP in the primary tumor and its metastases (p < 0.05; k = 0.48). TOLLIP expression significantly correlates with a lower overall survival rate (p = 0.047). TOLLIP functions as a ubiquitin-LC3 adaptor in the intracellular pathway associated with autophagy. Relative TOLLIP overexpression may augment autophagy-related signaling, limiting susceptibility to therapy. The blockade of TOLLIP physiological function seems to be a promising approach to overcoming resistance to systemic therapy.

The Role of Inflammatory Cytokines in the Pathogenesis of Colorectal Carcinoma-Recent Findings and Review.

The inflammatory process plays a significant role in the development of colon cancer (CRC). Intestinal cytokine networks are critical mediators of tissue homeostasis and inflammation but also impact carcinogenesis at all stages of the disease. Recent studies suggest that inflammation is of greater importance in the serrated pathway than in the adenoma-carcinoma pathway. Interleukins have gained the most attention due to their potential role in CRC pathogenesis and promising results of clinical trials. Malignant transformation is associated with the pro-tumorigenic and anti-tumorigenic cytokines. The harmony between proinflammatory and anti-inflammatory factors is crucial to maintaining homeostasis. Immune cells in the tumor microenvironment modulate immune sensitivity and facilitate cancer escape from immune surveillance. Therefore, clarifying the role of underlying cytokine pathways and the effects of their modulation may be an important step to improve the effectiveness of cancer immunotherapy.

The Prognostic Role of CDK9 in Bladder Cancer.

Introduction: Most patients with urothelial carcinoma are diagnosed with non-invasive tumors, but the prognosis worsens with the progression of the disease. Overexpression of cyclin-dependent kinase 9 has been recently linked to increased cancer proliferation, faster progression, and worse prognosis. However, some cancers seem to contradict this rule. In this work, we explored the prognostic role of CDK9 expression in urothelial carcinoma. Materials and Methods: We performed immunohistochemical analysis on 72 bladder cancer samples. To assess a larger group of patients, the Cancer Genome Atlas (TCGA) database containing 406 cases and transcriptomics information through the Human Pathology Atlas were analyzed. Results: CDK9 is overexpressed in urothelial cancer tissues when compared to normal urothelial tissues (p < 0.05). High CDK9 expression was observed in low-stage, low-grade, and non-muscle-invasive tumors (p < 0.05). The patients with high CDK9 expression had a significantly higher 5-year overall survival rate than those with low CDK9 expression (77.54% vs. 53.6% in the TMA group and 57.75% vs. 35.44% in the TCGA group, respectively) (p < 0.05). The results were consistent in both cohorts. Multivariate Cox regression analysis indicated that low CDK9 status was an independent predictor for poor prognosis in the TCGA cohort (HR 1.60, CL95% 1.1−2.33, p = 0.014). Conclusions: High CDK9 expression predicts a favorable prognosis in urothelial carcinoma and is associated with clinicopathological features characteristic for early-stage disease. The decrease in CDK9 expression can be associated with the build-up of genetic instability and may indicate a key role for CDK9 in the early stages of urothelial carcinoma.

CDK9 inhibitors in multiple myeloma: a review of progress and perspectives.

Currently, multiple myeloma is not yet considered a curable disease. Despite the recent advances in therapy, the average patient lifespan is still unsatisfactory. Recently, CDK9 inhibitors emerged as a suitable agent to overcome resistance and prolong survival in patients with poor diagnoses. Downregulation of c-MYC, XIAP, Mcl-1 and restoration of p53 tumor-suppressive functions seems to play a key role in achieving clinical response. The applicability of the first generation of CDK9 inhibitors was limited due to relatively high toxicity, but the introduction of novel, highly selective drugs, seems to reduce the effects of off-target inhibition. CDK9 inhibitors were able to induce dose-dependent cytotoxicity in Doxorubicin-resistant, Lenalidomide-resistant and Bortezomib-resistant cell lines. They seem to be effective in cell lines with unfavorable prognostic factors, such as p53 deletion, t(4; 14) and t(14; 16). In preclinical trials, the application of CDK9 inhibitors led to tumor cells apoptosis, tumor growth inhibition and tumor mass reduction. Synergistic effects between CDK9 inhibitors and either Venetoclax, Bortezomib, Lenalidomide or Erlotinib have been proven and are awaiting verification in clinical trials. Although conclusions should be drawn with due care, obtained reports suggest that including CDK9 inhibitors into the current drug regimen may turn out to be beneficial, especially in poor prognosis patients.

Current Challenges in Targeting Tumor Desmoplasia to Improve the Efficacy of Immunotherapy.

Desmoplasia is crucial for the development, progression and treatment of immune-resistant malignancies. Targeting desmoplasia-related metabolic pathways appears to be an interesting approach to expand our stock of disposable anti-tumor agents. CXCL12/CXCR4 axis inhibition reduces fibrosis, alleviates immunosuppression and significantly enhances the efficacy of PD-1 immunotherapy. CD40L substitute therapy may increase the activity of T-cells, downregulate CD40+, prolong patients' survival and prevent cancer progression. Although FAPα antagonists used in preclinical models did not lead to permanent cure, an alleviation of immune-resistance, modification of desmoplasia and a decrease in angiogenesis were observed. Targeting DDR2 may enhance the effect of anti-PD-1 treatment in multiple neoplasm cell lines and has the ability to overcome the adaptation to BRAF-targeted therapy in melanoma. Reprogramming desmoplasia could potentially cooperate not only with present treatment, but also other potential therapeutic targets. We present the most promising metabolic pathways related to desmoplasia and discuss the emerging strategies to improve the efficacy of immunotherapy.

CDK9: Therapeutic Perspective in HCC Therapy.

CDK9 is an important cell-cycle control enzyme essential in transcription, elongation, and mRNA maturation. Overexpression of CDK9 has been reported in several diseases, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, and malignant melanoma. Recent research revealed that CDK9-inhibitors have a major impact on the induction of apoptosis in hepatocellular carcinoma (HCC) cell lines. Despite surprisingly promising results in in vitro and in vivo research, no CDK9 related therapy is currently allowed in cases of HCC. Furthermore, due to their high specificity, the inhibitors had no effects on unaltered hepatocytes and no toxic effects were shown. Considering that they were well tolerated and showed relatively few severe side-effects in mice, CDK9- inhibitors would seem to be promising targets in HCC biomarker-guided immunotherapy. Studies have verified that CDK9 has a pivotal role in c-Myc-mediated tumor growth and CDK9 inhibitors inhibit not only its progression but diametrically decrease both the mass and size of HCC nodules. CDK9-inhibitors seem to be a promising target in HCC treatment.