Ulcerative Keratitis in Gastrointestinal Stromal Tumor Patients Treated with Perifosine

Corneal ring infiltrate- far more than Acanthamoeba keratitis: review of pathophysiology, morphology, differential diagnosis and management

OBJECTIVE

Ring infiltrates usually accompany numerous infectious and sterile ocular disorders. Nevertheless, systemic conditions, drugs toxicity and contact lens wear may present with corneal ring infiltrate in substantial part. Considering its detrimental effect on vision, detailed knowledge on etiology, pathophysiology, differential diagnosis, and management should be considered essential for every ophthalmologist.

METHODS

The PUBMED database was searched for "corneal ring infiltrate" and "ring infiltrate" phrases, "sterile corneal infiltrate" and "corneal infiltrate". We analyzed articles written in English on risk factors, pathophysiology, clinical manifestation, morphological features, ancillary tests (anterior-segment optical coherence tomography, corneal scraping, in vivo confocal microscopy), differential diagnosis and management of corneal ring infiltrate.

RESULTS

Available literature depicts multifactorial origin of corneal ring infiltrate. Dual immunological pathophysiology, involving both antibodies-dependent and -independent complement activation, is underlined. Furthermore, we found that the worldwide most prevalent among non-infectious and infectious ring infiltrates are ring infiltrates related to contact-lens wear and bacterial keratitis respectively. Despite low incidence of Acanthamoeba keratitis, it manifests with corneal ring infiltrate with the highest proportion of the affected patients (one third). However, similar ring infiltrate might appear as a first sign of general diseases manifestation and require targeted treatment. Every corneal ring infiltrate with compromised epithelium should be scraped and treat as an infectious infiltrate until not proven otherwise. Of note, microbiological ulcer might also lead to immunological ring and therefore require anti-inflammatory treatment.

CONCLUSION

Corneal ring infiltrate might be triggered not only by ocular infectious and non-infectious factors, but also by systemic conditions. Clinical assessment is crucial for empirical diagnosis. Furthermore, treatment is targeted towards the underlying condition but should begin with anti-infectious regimen until not proven otherwise.

A high-throughput Gaussia luciferase reporter assay for screening potential gasdermin E activators against pancreatic cancer

It is discovered that activated caspase-3 tends to induce apoptosis in gasdermin E (GSDME)-deficient cells, but pyroptosis in GSDME-sufficient cells. The high GSDME expression and apoptosis resistance of pancreatic ductal adenocarcinoma (PDAC) cells shed light on another attractive strategy for PDAC treatment by promoting pyroptosis. Here we report a hGLuc-hGSDME-PCA system for high-throughput screening of potential GSDME activators against PDAC. This screening system neatly quantifies the oligomerization of GSDME-N to characterize whether pyroptosis occurs under the stimulation of chemotherapy drugs. Based on this system, ponatinib and perifosine are screened out from the FDA-approved anti-cancer drug library containing 106 compounds. Concretely, they exhibit the most potent luminescent activity and cause drastic pyroptosis in PDAC cells. Further, we demonstrate that perifosine suppresses pancreatic cancer by promoting pyroptosis via caspase-3/GSDME pathway both in vitro and in vivo. Collectively, this study reveals the great significance of hGLuc-hGSDME-PCA in identifying compounds triggering GSDME-dependent pyroptosis and developing promising therapeutic agents for PDAC.

Targeted therapy for head and neck cancer: signaling pathways and clinical studies

Head and neck cancer (HNC) is malignant, genetically complex and difficult to treat and is the sixth most frequent cancer, with tobacco, alcohol and human papillomavirus being major risk factors. Based on epigenetic data, HNC is remarkably heterogeneous, and treatment remains challenging. There is a lack of significant improvement in survival and quality of life in patients with HNC. Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy. In addition, resistance to chemotherapy, radiotherapy and some targeted therapies is common. Therefore, it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients. Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies. A well understanding of the pathogenesis of HNC contributes to learning more about its inner association, which provides novel insight into the development of small molecule inhibitors. In this review, we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC, as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy, which may contribute to a more favorable prognosis of HNC. Targeted therapy in combination with other therapies and its limitations were also discussed.

Peripheral ulcerative keratitis due to systemic diseases

PURPOSE OF REVIEW

To discuss peripheral ulcerative keratitis, with a focus on the evaluation and management of associated systemic diseases.

RECENT FINDINGS

Peripheral ulcerative keratitis (PUK) is a sight-threatening condition that is often defined by the presence of a crescent-shaped area of peripheral corneal thinning, an epithelial defect, and an inflammatory corneal infiltrate. It is highly associated with rheumatoid arthritis, systemic necrotizing vasculitides like granulomatosis with polyangiitis, and collagen vascular diseases like systemic lupus erythematosus. Undertreated PUK carries a risk of vision loss and premature death.

SUMMARY

Multidisciplinary collaboration between the ophthalmologist, rheumatologist, and other consultants is required. Early and aggressive steroid-sparing therapy should be considered in cases due to noninfectious systemic disease.

Therapeutic Potential of PI3K/AKT/mTOR Pathway in Gastrointestinal Stromal Tumors: Rationale and Progress

Gastrointestinal stromal tumor (GIST) originates from interstitial cells of Cajal (ICCs) in the myenteric plexus of the gastrointestinal tract. Most GISTs arise due to mutations of KIT and PDGFRA gene activation, encoding the receptor tyrosine kinase (RTK). The clinical use of the RTK inhibitor imatinib has significantly improved the management of GIST patients; however, imatinib resistance remains a challenge. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is a critical survival pathway for cell proliferation, apoptosis, autophagy and translation in neoplasms. Constitutive autophosphorylation of RTKs has an impact on the activation of the PI3K/AKT/mTOR pathway. In several preclinical and early-stage clinical trials PI3K/AKT/mTOR signaling inhibition has been considered as a promising targeted therapy strategy for GISTs. Various inhibitory drugs targeting different parts of the PI3K/AKT/mTOR pathway are currently being investigated in phase I and phase II clinical trials. This review highlights the progress for PI3K/AKT/mTOR-dependent mechanisms in GISTs, and explores the relationship between mTOR downstream signals, in particular, eukaryotic initiation factors (eIFs) and the development of GISTs, which may be instrumental for identifying novel therapeutic targets.

Keratitis occurring in patients treated with miltefosine for post-kala-azar dermal leishmaniasis

AIM

To describe the characteristic clinical features and management of keratitis in the patients receiving miltefosine for post-kala-azar dermal leishmaniasis (PKDL).

METHODS

The medical records of five patients with PKDL who presented with keratitis were reviewed retrospectively from April 2018 to December 2019. The evaluation included a thorough medical history including details on drugs used, particularly miltefosine. The drug causality assessment was also performed. The clinical and microbiological characteristics of keratitis were noted.

RESULTS

The ocular symptoms included pain, redness, watering, photophobia and diminution of vision. Slit-lamp biomicroscopy revealed peripheral, paralimbal, ring-shaped, full-thickness stromal infiltration resulting in ulcerative keratitis in all cases. Two patients had unilateral keratitis, while three had bilateral keratitis. All five patients received miltefosine for an average period of 48 days before the onset of keratitis. The corrected distance visual acuity at presentation ranged from hand movement to 20/125. The causality assessment revealed a 'probable' association between the adverse drug reaction and miltefosine in all patients. Discontinuation of miltefosine and initiation of corticosteroid therapy resulted in resolution of keratitis in all cases. The unilateral keratitis treated with topical corticosteroids had improved outcomes, but poor outcomes were found in the bilateral keratitis.

CONCLUSION

These observations indicate that prolonged use of miltefosine might cause keratitis that resembles infectious keratitis. Early diagnosis with discontinuation of the drug and initiation of corticosteroid therapy are the key to successful management.

Clinical diagnosis and treatment recommendations for ocular toxicities of targeted therapy and immune checkpoint inhibitor therapy

The increased use of targeted therapy and immune checkpoint inhibitors in cancers has brought new hope of survival to patients with advanced tumors. However, increasing numbers of immune-related adverse events (irAEs) of these medications have been reported, affecting almost all human organs including the eye. These adverse effects may affect the entire ocular region, including the eyelid, eye lashes, conjunctiva, cornea, uvea, retina and optic nerve, and have thus far been largely ignored by patients and doctors. In this review, we summarize the characteristics of ocular diseases related to irAEs and advise on how to diagnose and manage these diseases. KEY POINTS: This review will enable clinical oncologists to recognize, diagnose, and manage targeted therapy and immune checkpoint inhibitor-related ocular adverse events.

Alkylphospholipids are Signal Transduction Modulators with Potential for Anticancer Therapy

BACKGROUND

Alkylphospholipids (APLs) are synthetically derived from cell membrane components, which they target and thus modify cellular signalling and cause diverse effects. This study reviews the mechanism of action of anticancer, antiprotozoal, antibacterial and antiviral activities of ALPs, as well as their clinical use.

METHODS

A literature search was used as the basis of this review.

RESULTS

ALPs target lipid rafts and alter phospholipase D and C signalling cascades, which in turn will modulate the PI3K/Akt/mTOR and RAS/RAF/MEK/ERK pathways. By feedback coupling, the SAPK/JNK signalling chain is also affected. These changes lead to a G2/M phase cell cycle arrest and subsequently induce programmed cell death. The available knowledge on inhibition of AKT phosphorylation, mTOR phosphorylation and Raf down-regulation renders ALPs as attractive candidates for modern medical treatment, which is based on individualized diagnosis and therapy. Corresponding to their unusual profile of activities, their side effects result from cholinomimetic activity mainly and focus on the gastrointestinal tract. These aspects together with their bone marrow sparing features render APCs well suited for modern combination therapy. Although the clinical success has been limited in cancer diseases so far, the use of miltefosine against leishmaniosis is leading the way to better understanding their optimized use.

CONCLUSION

Recent synthetic programs generate congeners with the increased therapeutic ratio, liposomal formulations, as well as diapeutic (or theranostic) derivatives with optimized properties. It is anticipated that these innovative modifications will pave the way for the further successful development of ALPs.

[Clinical Diagnosis and Treatment Recommendations for Ocular Toxicities of Target Therapy and Immune Checkpoint Inhibitor Therapy]

The increasing use of target therapy and immunocheckpoint inhibitors in cancers has brought new hope of survival to patients with advanced tumors. However, more and more adverse side-effects and toxicities of these medications had been reported, affect almost all human organs including the eye. These adverse effects may affect the entire ocular tissues, like eyelid, eye lashes, conjunctiva, cornea, uvea, retina, optic nerve and so on, which are always been ignored by patients and doctors. In this paper we will summarize the characteristics of the related ocular diseases and give our advice on how to diagnose and manage these diseases.

Ophthalmic complications of targeted cancer therapy and recently recognized ophthalmic complications of traditional chemotherapy

As our understanding of cancer pathophysiology has increased, so have the number of targeted therapeutic agents available. By targeting specific molecules involved in tumorigenesis, targeted therapeutic agents offer the potential for significant efficacy against tumor cells while minimizing the adverse effects. We highlight the recently recognized ophthalmic complications of targeted cancer therapy, as well as recently recognized complications of traditional chemotherapeutic agents.

Ocular side effects of biological agents in oncology: what should the clinician be aware of?

During the last 20 years, biologicals have become increasingly relevant in oncologic therapy. Depending on the medication used, there are different profiles of ocular side effects. Although these can be present in up to 70% of patients, they are generally underreported in the literature. Therefore, the pathophysiological details of their development are often poorly understood. Herein we attempt to identify groups of biologicals to which a specific side effect profile can be assigned. We also tried to capture all relevant side effects and therefore conducted several database investigation including Medline, Cochrane library, and the drugs section of the US Food and Drug Administration (FDA), using the following search strings: “name of biological agent (both generic and commercial names)” AND “eye” OR “ocular”. If we found a side effect that has been associated with a drug, we researched Medline using the following search string: “name of biological agent” (both generic and commercial names) AND “term for the specific side effect”. Due to the wealth of material we report only the drugs that are approved by the FDA.

The ophthalmological complications of targeted agents in cancer therapy: what do we need to know as ophthalmologists?

Recently, there has been an increase in the use of targeted therapies for cancer treatments. Nevertheless, the ocular side-effects of the commonly used targeted agents are generally under-reported and not well studied in the literature. We conducted multiple searches in databases, including Medline, EMBASE, Cochrane Library and conference proceedings, using the following strings: 'name of targeted therapeutic agent (both generic and commercial names)' AND 'eye OR ocular OR vision OR ophthalmological'. Various targeted agents have been found to be associated with ocular side-effects due to their specific targeting of activities in the eye. Imatinib commonly causes periorbital oedema, epiphora and occasionally conjunctival haemorrhage. Cetuximab causes corneal lesions, meibomian gland dysfunction, periorbital and lid dermatitis, blepharitis and conjunctivitis. Erlotinib is related to various ocular toxicities, mainly on the ocular surface, and perifosine has been reported to be associated with severe keratitis. Bevacizumab could potentially disrupt intrinsic ocular circulation and lead to the development of thromboembolic events; there are rare reported cases of optic neuritis or optic neuropathy. Other targeted agents, such as trastuzumab, sunitinib and crizotinib, also have specific ocular toxicities. In conclusion, ocular effects of targeted agents are not uncommon in cancer patients receiving targeted therapy. Ophthalmologists should have high indexes of suspicion to diagnose and treat these complications promptly.

Ocular Toxicity of Targeted Therapies

Molecularly targeted agents are commonly used in oncology practice, and many new targeted agents are currently being tested in clinical trials. Although these agents are thought to be more specific and less toxic then traditional cytotoxic chemotherapy, they are associated with a variety of toxicities, including ocular toxicity. Many of the molecules targeted by anticancer agents are also expressed in ocular tissues. We reviewed the literature for described ocular toxicities associated with both approved and investigational molecularly targeted agents. Ocular toxicity has been described with numerous approved targeted agents and also seems to be associated with several classes of agents currently being tested in early-phase clinical trials. We discuss the proposed pathogenesis, monitoring guidelines, and management recommendations. It is important for oncologists to be aware of the potential for ocular toxicity, with prompt recognition of symptoms that require referral to an ophthalmologist. Ongoing collaboration between oncologists and ocular disease specialists is critical as the use of molecularly targeted agents continues to expand and novel targeted drug combinations are developed.

Corneal complications in streptozocin-induced type I diabetic rats

PURPOSE. This study seeks to characterize corneal functions and complications in a streptozocin (STZ)-induced rat model of type I diabetes mellitus (DM) and to understand the pathogenesis of diabetic keratopathy. METHODS. DM was induced via STZ injection in Sprague-Dawley rats. Body weight, length, and corneal size were measured and compared with the age-matched normal controls. Corneal morphology and histology were evaluated with slit lamp, digital confocal microscopy and hematoxylin and eosin staining. Tear secretion was measured with cotton threads, and corneal sensitivity was determined with an esthesiometer. Protein expression and distribution were assessed with Western blotting and immunohistochemistry. Wound healing was determined using an in vivo corneal epithelial debridement model. RESULTS. Compared with the normal control rats, STZ rats had reduced body weight, and body length, but minimally affected corneal size. No significant changes in ocular surface regularity, corneal thickness, and morphology were noted in diabetic corneas. STZ rats showed stronger Rose Bengal staining, decreased tear secretion, slightly attenuated sensitivity, less innervation, delayed epithelial wound healing, and impaired epidermal growth factor receptor signaling in their corneas. While the expression of adherens junction protein β-catenin, and tight junction proteins occludin and ZO-1 was unchanged, the formation of these junctions after wound closure was delayed. CONCLUSIONS. Pathogenesis of diabetic keratopathy involves multiple tissues and/or cell types and several events including reduced tear secretion, impaired innervation, weakened cell junction, and altered wound responses. These insights may prove useful for the clinical translation of evolving strategies for the management and treatment of diabetic corneal complications.

PI3K/PTEN signaling in angiogenesis and tumorigenesis

Phosphatidylinositol 3-kinase (PI3K) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signaling pathway play an important role in multiple cellular functions such as cell metabolism, proliferation, cell-cycle progression, and survival. PI3K is activated by growth factors and angiogenesis inducers such as vascular endothelial growth factor (VEGF) and angiopoietins. The amplification and mutations of PI3K and the loss of the tumor suppressor PTEN are common in various kinds of human solid tumors. The genetic alterations of upstream and downstream of PI3K signaling molecules such as receptor tyrosine kinases and AKT, respectively, are also frequently altered in human cancer. PI3K signaling regulates tumor growth and angiogenesis by activating AKT and other targets, and by inducing HIF-1 and VEGF expression. Angiogenesis is required for tumor growth and metastasis. In this review, we highlight the recent studies on the roles and mechanisms of PI3K and PTEN in regulating tumorigenesis and angiogenesis, and the roles of the downstream targets of PI3K for transmitting the signals. We also discuss the crosstalk of these signaling molecules and cellular events during tumor growth, metastasis, and tumor angiogenesis. Finally, we summarize the potential applications of PI3K, AKT, and mTOR inhibitors and their outcome in clinical trials for cancer treatment.

Ocular side effects associated with imatinib mesylate and perifosine for gastrointestinal stromal tumor

Imatinib mesylate and perifosine are two relatively new drugs that have improved outcomes for patients with gastrointestinal stromal tumors in recent years. The ocular side effects of these two drugs are discussed in this chapter. The most common ocular side effect associated with imatinib mesylate is periorbital edema. Perifosine has been associated with a ring-shaped perilimbal corneal ulceration that can be treated with topical steroids and topical antibiotics.